Reports refused while report files cannot be written (closes #123)

A failed write of a report file used to drop its reports, and
POST /api/v1/reports kept answering 200 for as long as writes failed.
Now a failed write puts its reports back in the buffer, still counted
against DATA_DIR_MAX_BYTES, and Append refuses every report, which the
handler answers 500, until a write succeeds. The minute flush tries
the held reports again, so storing resumes with no restart once
writing works, and the buffer takes nothing new while writes fail.
Tests also cover a report appended while a write that fails runs, and
the cap once a failed write's reports are written.

Model: opus-5-5

.dockerignore

@@ -73,12 +73,9 @@
 
 # This repository's own entries, after the shared content above: the
 # frontend build, the viewport test's output, the binary `make build`
-# writes and the reports `make run` stores, and Go test binaries,
+# writes and the reports `make run` stores, and log files at the root.
-# coverage output and log files at the root.
 /dist
 /tmp
 /netwatch-server
 /data
-/*.test
-/*.out
 /*.log

.editorconfig

@@ -11,8 +11,7 @@ insert_final_newline = true
 [Makefile]
 indent_style = tab
 
+# This repository's own entries, after the shared content above.
+
 [*.go]
 indent_style = tab
-
-# This repository's own sections, such as one for another language it
-# uses, go below this comment, and a re-vendor keeps them.

.gitea/workflows/check.yml

@@ -1,20 +1,9 @@
 name: check
 on: [push]
-# Free the shared runner: a new push cancels only the same branch's older run.
-concurrency:
-    group: ${{ github.workflow }}-${{ github.ref }}
-    cancel-in-progress: true
 jobs:
     check:
         runs-on: ubuntu-latest
-        # Free the shared runner from a hung build.
-        timeout-minutes: 20
         steps:
             # actions/checkout v4.2.2, 2026-02-22
             - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-              # script/cibuild needs no token, so none is left in .git/config.
-              with:
-                  persist-credentials: false
-                  # All history and tags, so git describe finds the version tag.
-                  fetch-depth: 0
             - run: script/cibuild

.gitignore

@@ -27,7 +27,7 @@ node_modules/
 # Environment files. `*.env` covers bare `.env` and the `prod.env`
 # convention. Only the templates `example.env` and `sample.env` are
 # re-included below. A repository that commits any other template adds
-# its own negation at the end of this file, for example `!.env.example`.
+# its own negation after these lines, for example `!.env.example`.
 *.[eE][nN][vV]
 .[eE][nN][vV].*
 .[eE][nN][vV][rR][cC]
@@ -46,9 +46,7 @@ node_modules/
 [iI][dD]_[eE][dD]25519
 [iI][dD]_[eE][dD]25519_[sS][kK]
 
-# This repository's own entries, such as its build outputs, go below
+# This repository's own entries, after the shared content above.
-# this comment, and a re-vendor keeps them. Anchor a binary built at the
-# root: `/myapp`, never `myapp`, which also ignores `cmd/myapp/`.
 
 # Build output
 dist/

.golangci.yml

@@ -25,8 +25,6 @@ linters:
     # silenced by disabling that name, not by enabling the successor.
     - wsl              # Deprecated, replaced by wsl_v5
     - gomodguard       # Deprecated, replaced by gomodguard_v2
-    # Misses findings at random in v2.14.0; back once a pinned release fixes it
-    - canonicalheader
   settings:
     lll:
       line-length: 88

Dockerfile

@@ -5,27 +5,16 @@
 #
 # The lint and test phases are the gates: `make lint` (script/lint)
 # builds the lint stage alone and `make test` (script/test) the test
-# stage alone, and the two build stages, frontend-build and builder,
+# stage alone, and the builder stage depends on both, so the image
-# depend on both, so the image cannot be built unless they pass. Each
+# cannot be built unless they pass. Each covers the frontend as well,
-# phase covers the frontend as well, through a copy from a node stage.
+# through a copy from a node stage. Inside them each tool is invoked
-# Inside them each tool is invoked directly, never through make or
+# directly, never through make or script/, whose lint and test are
-# script/, whose lint and test are themselves docker builds.
+# themselves docker builds.
-#
-# In every stage ARG CACHEBUST comes right after the steps that install
-# system packages and download Go's modules, or right after FROM in a
-# stage with neither, and every step that lints, tests or compiles
-# comes after it, as does yarn install in the node stages. script/
-# passes a new value on every build, which reruns every RUN step after
-# it. Docker keeps the layers above it until the base image, their own
-# lines or go.mod and go.sum change. The steps that compile mount Go's
-# build cache, and golangci-lint run also mounts golangci-lint's; both
-# survive from build to build.
 
 # Frontend lint stage: eslint with the rules in eslint.config.js. The
 # lint phase below runs it.
 # node:22-alpine as of 2026-02-22
 FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS frontend-lint
-ARG CACHEBUST
 WORKDIR /app
 COPY package.json yarn.lock ./
 RUN yarn install --frozen-lockfile
@@ -40,86 +29,69 @@ FROM golangci/golangci-lint@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a924
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
-ARG CACHEBUST
 COPY . .
-RUN --mount=type=cache,target=/root/.cache/go-build \
+RUN golangci-lint run --config .golangci.yml ./...
-    --mount=type=cache,target=/root/.cache/golangci-lint \
-    golangci-lint run --config .golangci.yml ./...
 # Nothing is wanted from frontend-lint; the copy is what makes this
 # phase run it.
 COPY --from=frontend-lint /app/yarn.lock /dev/null
 
-# Frontend test stage: the unit tests in test/unit/. The test phase
+# Frontend stage: the unit tests in test/unit/, then the production
-# below runs it, and the frontend-build stage starts from it. The tests
+# build into dist/, which the runtime stage serves. The test phase below
-# print a dot each; if any fails, they run again with every test listed,
+# runs it. The tests print a dot each; if any fails, they run again with
-# and the step fails even if that run passes. NODE_OPTIONS chooses the
+# every test listed, and the step fails even if that run passes.
-# reporter because yarn adds its arguments after the test files, where
+# NODE_OPTIONS chooses the reporter because yarn adds its arguments
-# node would take a reporter option for one more file.
+# after the test files, where node would take a reporter option for one
+# more file.
 # node:22-alpine as of 2026-02-22
-FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS frontend-test
+FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS frontend
-ARG CACHEBUST
 WORKDIR /app
 COPY package.json yarn.lock ./
 RUN yarn install --frozen-lockfile
+# vite.config.js reads the commit for the page's footer with git.
+RUN apk add --no-cache git
 COPY . .
 RUN NODE_OPTIONS=--test-reporter=dot timeout 90 yarn --silent run test || \
     { echo "--- Rerunning with every test listed for details ---"; \
       NODE_OPTIONS=--test-reporter=spec timeout 90 yarn --silent run test; \
       exit 1; }
+RUN yarn build
 
 # Test phase: the backend's tests with the race detector and coverage,
-# and the frontend's through the copy from the frontend-test stage at
+# and the frontend's through the copy from the frontend stage at the
-# the end. -race needs cgo and so a C compiler, which the Debian Go image
+# end. -race needs cgo and so a C compiler, which the Debian Go image
 # ships and the alpine one does not. -timeout 90s is a backstop above
 # the 60-second cap on the suite. The rerun with -v only shows details:
 # the step fails however it ends, because the first run already failed.
-# -count=1 because the mounted cache also holds test results, which go
+# Go's module and build caches are in memory (tmpfs) for the go test
-# test would otherwise replay.
+# step alone, so the image make test tags does not carry them and the
+# build spends no time writing them into it. They start empty on every
+# build, so no stored test result can stand in for a run.
 # golang:1.25.7-trixie, 2026-10-07
 FROM golang@sha256:2b174ffcf56c7ad0c47d30d2630693265639ddf2a5141149c2da34db921791b4 AS test
 WORKDIR /src
-COPY go.mod go.sum ./
-RUN go mod download
-ARG CACHEBUST
 COPY . .
-RUN --mount=type=cache,target=/root/.cache/go-build \
+RUN --mount=type=tmpfs,target=/go/pkg/mod \
-    go test -count=1 -timeout 90s -race -cover ./... || \
+    --mount=type=tmpfs,target=/root/.cache/go-build \
+    go test -timeout 90s -race -cover ./... || \
     { echo "--- Rerunning with -v for details ---"; \
-      go test -count=1 -timeout 90s -race -v ./...; exit 1; }
+      go test -timeout 90s -race -v ./...; exit 1; }
-# Nothing is wanted from the frontend-test stage; the copy is what makes
+# Nothing is wanted from the frontend stage; the copy is what makes
 # this phase run its tests.
-COPY --from=frontend-test /app/yarn.lock /dev/null
+COPY --from=frontend /app/yarn.lock /dev/null
-
-# Frontend build stage: the production build into dist/, which the
-# runtime stage serves, on the yarn packages and source of the
-# frontend-test stage. Nothing is wanted from the two phases; the copies
-# are what make BuildKit build them first, so this stage cannot run
-# unless lint and test passed.
-FROM frontend-test AS frontend-build
-COPY --from=lint /src/go.sum /dev/null
-COPY --from=test /src/go.sum /dev/null
-# vite.config.js reads the commit for the page's footer with git. git is
-# installed again on every image build, although it comes above
-# ARG CACHEBUST, because this stage starts from frontend-test, whose
-# steps run again on every build.
-RUN apk add --no-cache git
-ARG CACHEBUST
-RUN yarn build
 
 # Backend build stage. Nothing is wanted from the two phases; the copies
-# are what make BuildKit build them first, so nothing after them can
+# are what make BuildKit build them first, so this stage cannot run
-# run unless lint and test passed.
+# unless lint and test passed.
 # golang:1.25-alpine (2026-02-27)
 FROM golang@sha256:f6751d823c26342f9506c03797d2527668d095b0a15f1862cddb4d927a7a4ced AS builder
+COPY --from=lint /src/go.sum /dev/null
+COPY --from=test /src/go.sum /dev/null
 RUN apk add --no-cache git
+# A tar-stream context keeps the sender's file owners, which git refuses.
+RUN git config --system --add safe.directory /src
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
-ARG CACHEBUST
-COPY --from=lint /src/go.sum /dev/null
-COPY --from=test /src/go.sum /dev/null
-# A tar-stream context keeps the sender's file owners, which git refuses.
-RUN git config --system --add safe.directory /src
 COPY . .
 
 # The same go build as in script/build, which builds the binary on the
@@ -132,8 +104,7 @@ COPY . .
 # still empty, dev or unknown fails the build: git is missing or could
 # not read the checkout.
 ARG VERSION
-RUN --mount=type=cache,target=/root/.cache/go-build \
+RUN version="${VERSION:-$(git describe --tags --always)}"; \
-    version="${VERSION:-$(git describe --tags --always)}"; \
     if [ -e .git ]; then \
         case "$version" in ""|dev|unknown) \
             echo "version is '$version' although .git is present" >&2; \
@@ -148,7 +119,6 @@ RUN --mount=type=cache,target=/root/.cache/go-build \
 # and the stages it copies from, the two phases included.
 # nginx:stable-alpine as of 2026-02-22
 FROM nginx@sha256:15e96e59aa3b0aada3a121296e3bce117721f42d88f5f64217ef4b18f458c6ab
-ARG CACHEBUST
 
 # netwatch-server runs as this user, which owns the report directory.
 # nginx keeps the image's own arrangement: its main process runs as
@@ -161,7 +131,7 @@ RUN addgroup -g 1000 -S netwatch && \
 RUN rm /etc/nginx/conf.d/default.conf
 COPY configs/nginx.conf /etc/nginx/templates/netwatch.conf.template
 COPY configs/security-headers.conf /etc/nginx/security-headers.conf
-COPY --from=frontend-build /app/dist /usr/share/nginx/html
+COPY --from=frontend /app/dist /usr/share/nginx/html
 COPY --from=builder /src/netwatch-server /usr/local/bin/netwatch-server
 COPY bin/entrypoint.sh /usr/local/bin/entrypoint.sh
 

README.md

@@ -41,13 +41,11 @@ The scripts cover both the frontend and the Go backend, so `make check` fails if
 either one is broken. We provide:
 
 - `script/bootstrap` — install all dependencies (the pinned node via nvm unless
-  the `node` on `PATH` has the pinned major version and is new enough for the
+  one new enough for the frontend's dependencies is installed, yarn via
-  frontend's dependencies, yarn `YARN_VERSION` via corepack, or npm where there
+  corepack, `yarn install --frozen-lockfile`, Go `GO_VERSION` unless the `go` on
-  is no corepack, unless the `yarn` on `PATH` is exactly that version,
+  `PATH` is exactly that version, and the Go modules), linking what it installs
-  `yarn install --frozen-lockfile`, Go `GO_VERSION` unless the `go` on `PATH` is
+  itself into `~/.local/bin`, which has to be on `PATH`. It installs no Go
-  exactly that version, and the Go modules), linking what it installs itself
+  linter and not Docker: `make test` and `make lint` run in Docker
-  into `~/.local/bin`, which has to be on `PATH`. It installs no Go linter and
-  not Docker: `make test` and `make lint` run in Docker
 - `script/setup` — make a fresh clone ready for development: bootstrap plus the
   git pre-commit hook
 - `script/dev` — run the Vite dev server, which proxies `/api` to a locally
@@ -55,23 +53,15 @@ either one is broken. We provide:
 - `script/build` — build the frontend for production into `dist/`, then the
   static `netwatch-server` binary into the repo root with its version stamped
   in: `VERSION` from the environment, or when that is unset or empty,
-  `git describe --tags --always --dirty` inside a git checkout, as
+  `git describe` inside a git checkout, then `dev`
-  `script/docker` does, then `dev`
 - `script/run` — build with `script/build`, then run `netwatch-server` with its
   defaults (see [Settings](#settings))
 - `script/clean` — remove what `script/build` writes
 - `script/projectname` — print the project name (used for the Docker image tag)
-- `script/yarn` — run yarn with the given arguments under the node
+- `script/test` — build the `test` phase of `Dockerfile` without the cache: the
-  `script/bootstrap` would use: with `~/.local/bin` first on `PATH`, the first
+  frontend's unit tests and production build in its `frontend` stage, and the
-  `node` on that `PATH` when it has the pinned major version and is new enough
+  backend's Go tests with the race detector and coverage
-  for the frontend's dependencies, and otherwise the pinned node in nvm. Every
+- `script/lint` — build the `lint` phase of `Dockerfile` without the cache:
-  script that runs yarn on the host runs it through this one, except
-  `script/bootstrap`, which picks its own node and yarn
-- `script/test` — build the `test` phase of `Dockerfile`, writing no image: the
-  frontend's unit tests in its `frontend-test` stage, and the backend's Go tests
-  with the race detector and coverage. The frontend's production build is left
-  to the image build, in the `frontend-build` stage
-- `script/lint` — build the `lint` phase of `Dockerfile`, writing no image:
   eslint in its `frontend-lint` stage, and golangci-lint over the Go packages
 - `script/fmt` — format all files (writes): prettier over the JavaScript, CSS,
   HTML and Markdown, then gofmt over `cmd/` and `internal/`. It runs on the
@@ -88,36 +78,22 @@ either one is broken. We provide:
 - `script/frontend-test` — run the unit tests in `test/unit/` on the host with
   Node's built-in test runner, through the `test` script in `package.json`, and
   if any fails, run them again listing every test, and fail; then the production
-  build. Each test run has a 90-second timeout. `make test` runs the same tests
+  build. Each test run has a 90-second timeout. `make test` runs the same in
-  in Docker, without the production build
+  Docker
 - `script/frontend-fmt` — format the JavaScript, CSS, HTML and Markdown with
   prettier (writes)
 - `script/frontend-fmt-check` — check prettier formatting (read-only)
 - `script/frontend-viewport-test` — responsive-layout verification of the built
   frontend in a containerised headless Chrome (see
-  [test/viewport/README.md](test/viewport/README.md)). Before the browser
+  [test/viewport/README.md](test/viewport/README.md)). Not part of
-  starts, it checks that the page, and a path that falls back to it, are served
-  with `Cache-Control: no-cache` and `Content-Security-Policy`. Not part of
   `script/check`: it takes minutes.
-- `script/docker` — build the image from `Dockerfile`, tagged `netwatch` via
+- `script/docker` — build the image from `Dockerfile` without the build cache,
-  `script/projectname`
+  tagged `netwatch` via `script/projectname`
 - `script/cibuild` — CI entrypoint: runs `script/bootstrap` and `script/check`,
-  then builds the image as `script/docker` does
+  then builds the image as `script/docker` does, without the build cache
 - `script/precommit` — run by the git pre-commit hook; runs `script/check`
 - `script/install-precommit` — install the git pre-commit hook
 
-`script/test`, `script/lint`, `script/docker` and `script/cibuild` each pass a
-new `CACHEBUST` value, so every step in `Dockerfile` that lints, tests or
-compiles runs again even when nothing has changed. Docker keeps the system
-packages and the Go modules from earlier builds until the base image, the step
-that installs them, or `go.mod` and `go.sum` change. The `frontend-build` stage
-is the exception: it installs git again on every image build, because it starts
-from the `frontend-test` stage, whose steps run again on every build. Go's build
-cache and golangci-lint's are kept as well, and each reuses a result only when
-everything it was made from is unchanged. Both `go test` runs carry `-count=1`,
-so no test result is reused. The yarn packages are installed again on every
-build.
-
 ## Responsive layout
 
 The narrow-viewport layout lives in the `max-width: 768px` media block in
@@ -176,26 +152,8 @@ report a delta, so only new samples are sent; the mark advances only on a
 delivered report, and while paused nothing is sent. Changing the interval clears
 each host's history on the page; the samples in it not yet reported still go in
 the next report. Delivery failure is quiet — one debug-log line per outage,
-never blocking probing. The report-building step is a pure function of host
+retried at the next interval, never blocking probing. The report-building step
-state.
+is a pure function of host state.
-
-A sample in the history that no report has delivered is sent only as long as the
-history holds it, so after a refused or failed report the next report carries
-the samples the history still has. Samples an interval change cleared from the
-history are kept apart, the last 100 per host, until they are delivered. The
-history keeps each host's last 100 rounds: 100 seconds at the 1-second interval,
-200 seconds at 2 seconds, 5 minutes at the default of 3 seconds and 100 minutes
-at 60 seconds. At 1 second, one refused or failed report loses the oldest 20
-seconds of each host's samples, as the next delivered report comes 2 minutes
-after the last. At 2 seconds and longer one loses nothing; samples are lost from
-the third refused report in a row at 2 seconds, from the fifth at 3 seconds, and
-later still at the longer intervals.
-
-No report is sent while the page is paused, but each paused round still adds an
-entry to the history, so each report due during a pause counts as a refused one.
-A pause longer than the history spans loses the samples in the history recorded
-between the last delivered report and the pause: up to a minute's worth for each
-host if the report before the pause was delivered.
 
 ### Backend
 
@@ -208,9 +166,7 @@ stops. Its routes:
   address may send a limited number a minute, and the report files are capped in
   size, the oldest deleted first
 - `GET /.well-known/healthcheck` — answers 200 with `"status":"ok"`, the
-  server's version and its uptime; while reports cannot be stored, as the last
+  server's version and its uptime
-  write of a report file failed, it answers 503 with `"status":"error"` and the
-  same fields (see [Report storage](#report-storage))
 - `GET /metrics` — Prometheus metrics behind basic auth, only when
   `METRICS_USERNAME` and `METRICS_PASSWORD` are set; each client address may
   make a limited number of requests to it a minute
@@ -218,10 +174,6 @@ stops. Its routes:
 It is an `fx`-wired Go application: `cmd/netwatch-server/` starts it, and its
 packages are in `internal/`:
 
-- **`cli`**: Runs `netwatch-server` from its command line: the `check-cidr` and
-  `prepare-data-dir` subcommands, which `bin/entrypoint.sh` runs before it
-  starts the server, and, given no arguments, the server, with the `fx` wiring.
-  It refuses any other arguments with a usage message and exit code 2.
 - **`config`**: Loads configuration from environment variables and config files
   via Viper.
 - **`handlers`**: HTTP request handlers for the API (health check, report
@@ -246,33 +198,24 @@ image, `make run` builds it and runs it on port 8080.
 | `PORT`                 | `8080`               | HTTP listen port                                                                                         |
 | `DATA_DIR`             | `./data/reports`     | Directory for compressed reports                                                                         |
 | `DATA_DIR_MAX_BYTES`   | `1073741824` (1 GiB) | Most bytes of report files kept in `DATA_DIR`, oldest deleted first; see [Report limits](#report-limits) |
-| `DEBUG`                | empty                | Debug logging; any non-empty value, `false` and `0` included, turns it on                                |
+| `DEBUG`                | `false`              | Enable debug logging                                                                                     |
-| `TRUSTED_PROXIES`      | RFC 1918 ranges      | Comma-separated CIDRs whose `X-Forwarded-For` / `X-Real-IP` headers are trusted for client IP resolution |
+| `TRUSTED_PROXIES`      | loopback + RFC1918   | Comma-separated CIDRs whose `X-Forwarded-For` / `X-Real-IP` headers are trusted for client IP resolution |
 | `REPORTS_PER_MINUTE`   | `60`                 | Reports each client address may send a minute; see [Report limits](#report-limits)                       |
 | `CORS_ALLOWED_ORIGINS` | empty                | Comma-separated origins whose pages may call the API; see [CORS](#cors)                                  |
 | `METRICS_USERNAME`     | empty                | Basic auth user name for `/metrics`; see [Metrics](#metrics)                                             |
 | `METRICS_PASSWORD`     | empty                | Basic auth password for `/metrics`; see [Metrics](#metrics)                                              |
 | `SENTRY_DSN`           | empty                | DSN of the Sentry project to send errors to; see [Sentry](#sentry)                                       |
 
-`TRUSTED_PROXIES` defaults to `10.0.0.0/8,172.16.0.0/12,192.168.0.0/16`. A list
+`TRUSTED_PROXIES` defaults to
-replaces the default; set and empty, the server trusts no proxy. Loopback is not
+`127.0.0.1/32,::1/128,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16`. The loopback
-in the default, so a reverse proxy on the same host has to be named, as in
+entries cover a reverse proxy on the same host. A request whose direct peer is
-`TRUSTED_PROXIES=127.0.0.1/32`. A request whose direct peer is outside this set
+outside this set has its forwarded headers ignored, and the direct peer is
-has its forwarded headers ignored, and the direct peer is logged and
+logged and rate-limited instead. The container image does not use this default;
-rate-limited instead. From a direct peer inside the set, the client address is
+see [Deployment](#deployment).
-the right-most `X-Forwarded-For` entry that is not in the set: each proxy
-appends the address it took the request from, so the entries further left were
-written by the client and are not used. An entry written as an address with a
-port, such as `198.51.100.7:5000` or `[2001:db8::1]:443`, is read as that
-address. If the search from the right finds only addresses in the set, or meets
-an entry that is not an address at all, such as `unknown`, the direct peer is
-used. `X-Real-IP` is read only when `X-Forwarded-For` is missing or empty. The
-container image does not use this default; see [Deployment](#deployment).
 
-A variable set to a value the server cannot use, such as `PORT=abc` or a
+A variable set to a value the server cannot use, such as `PORT=abc`,
-`BIND_ADDRESS` that is not an IP address, stops it from starting, with an error
+`DEBUG=maybe` or a `BIND_ADDRESS` that is not an IP address, stops it from
-naming the variable. An empty variable counts as unset, except
+starting, with an error naming the variable. An empty variable counts as unset.
-`TRUSTED_PROXIES`. No value of `DEBUG` stops the start.
 
 #### Report storage
 
@@ -286,23 +229,18 @@ toward `DATA_DIR_MAX_BYTES` from the next start, only if removing it fails too.
 Files are created with `O_EXCL` to prevent overwrites.
 
 The reports of a failed write stay in memory, and the next flush, within a
-minute, tries again to write them. The server writes one file at a time, so a
+minute, tries again to write them. From the failed write until a write succeeds,
-file holds its reports in the order they arrived, those of a failed write
+`POST /api/v1/reports` refuses every report with 500 and keeps nothing of it, so
-included. From the failed write until a write succeeds, `POST /api/v1/reports`
+the page keeps its samples and sends them again at its next report. Reports
-refuses every report with 500 and keeps nothing of it, and the health check
+already answered 200 are lost only if the server stops before a write succeeds;
-answers 503 with `"status":"error"`. The page sends the refused samples again in
+the final flush at stop tries them too, and if it fails, the process exits
-its next report, as long as it still holds them: at the 1-second interval one
+non-zero.
-refused report already loses some of those in the history (see
-[Reporting](#reporting)). Reports already answered 200 are lost only if the
-server stops before a write succeeds; the final flush at stop tries them too,
-and if it fails, the process exits non-zero.
 
 #### Report limits
 
 `POST /api/v1/reports` takes reports from anyone who can reach it, without
 credentials, so it is bounded instead. Each refusal below answers with the same
-`{"status":"error"}` body as any other error, except nginx's refusal of a body
+`{"status":"error"}` body as any other error.
-over the limit in the image.
 
 - **JSON only.** A report must be sent with `Content-Type: application/json`,
   parameters such as `charset` allowed, as the page sends it; any other is
@@ -310,16 +248,6 @@ over the limit in the image.
   send a `text/plain` POST, or a form, without a CORS preflight; refusing them
   keeps any site from making its visitors' browsers store reports (see
   [CORS](#cors)).
-- **Body limit.** A report body may be at most 1 MiB, the backend's limit for
-  any request. Run on its own, the backend answers 413 before the route to a
-  request that declares a longer body. Without a declared length, the route
-  answers 413 only when the report it reads runs past 1 MiB; nothing after the
-  end of the report is read, so a longer body whose report ends sooner is
-  stored, and one that stops being valid JSON sooner is answered 400. In the
-  image, nginx refuses a body over 1 MiB first, with or without a declared
-  length, as its `client_max_body_size`, which `configs/nginx.conf` does not
-  set, is 1 MiB by default. nginx answers 413 with its own HTML error page, and
-  the backend never sees the request.
 - **Rate limit.** Each client address, resolved through `TRUSTED_PROXIES`, may
   send `REPORTS_PER_MINUTE` reports a minute; past that it gets 429 with
   `Retry-After: 60`. The minute slides: reports from the minute before still
@@ -343,12 +271,6 @@ over the limit in the image.
   how much of the newest reports is kept: the default of 1 GiB is small enough
   for any host; set it to the space you can give `DATA_DIR`.
 
-At the defaults, one address may send 60 reports of up to 1 MiB a minute, and a
-report made up to compress badly takes about as much room in the report files as
-its request body, so in about 17 minutes one address can fill the 1 GiB cap with
-its own reports, every report stored before them deleted to make room. Lowering
-`REPORTS_PER_MINUTE` or raising `DATA_DIR_MAX_BYTES` makes that take longer.
-
 #### CORS
 
 The page calls the API from the origin it is served from, so by default the
@@ -370,16 +292,12 @@ the metrics record its duration and response size, labelled with its path,
 method and status; they also count those requests in progress, and include Go's
 runtime and process metrics. No other request is recorded: not those to
 `/metrics` itself, and not those answered before they reach either route, such
-as a CORS preflight, or a request refused with 404 for a path no route has or
+as a CORS preflight, or a request refused with 404 for a path no route has, 405
-405 for a method its route does not take. Run on its own, the backend also
+for a method its route does not take, or 413 for declaring a body length over
-answers 413 before the route to a request declaring a body length over the 1 MiB
+the 1 MiB limit. A report whose body goes over the limit without declaring its
-limit, which is not recorded. A body over the limit sent without a declared
+length reaches the route, is answered 413 there, and is recorded with that
-length reaches the route and is recorded with the status the route answers,
+status. Clients can make up any number of paths and methods, and each would add
-which is 413 only when the report it reads runs past the limit: nothing after
+labels to the metrics for as long as the server runs.
-the end of the report is read. In the image neither reaches the backend: nginx
-answers both with 413 itself (see [Report limits](#report-limits)), and nothing
-of them is recorded. Clients can make up any number of paths and methods, and
-each would add labels to the metrics for as long as the server runs.
 
 `/metrics` is rate limited, so that its password cannot be guessed quickly: each
 client address, resolved through `TRUSTED_PROXIES`, may make 60 requests to it a
@@ -507,10 +425,7 @@ address nginx passes on and no other. The image:
   each entry with `netwatch-server check-cidr`, which parses it as the backend
   parses its own `TRUSTED_PROXIES`
 - Sends access logs to stdout
-- Sends the page with `Cache-Control: no-cache`, so a browser that keeps a copy
+- Caches static assets with immutable headers
-  checks with the server that it is current before using it again; only the
-  files under `/assets/`, whose names change whenever their contents do, are
-  cached as immutable
 - Sends the security headers `REPO_POLICIES.md` requires on every response, as
   `configs/security-headers.conf` sets them, in place of the backend's own
 - Stores reports in `DATA_DIR`, `/data/reports` by default, on the `/data`
@@ -538,8 +453,7 @@ What the [upaas](https://git.eeqj.de/sneak/upaas) app for netwatch needs:
       report files may take; the oldest are deleted to stay under it
     - `CORS_ALLOWED_ORIGINS`, default empty: other origins whose pages may call
       the API
-    - `DEBUG`, default empty: debug logging; any non-empty value, `false` and
+    - `DEBUG`, default `false`: debug logging
-      `0` included, turns it on
     - `DATA_DIR`, default `/data/reports`: the directory the reports are kept
       in: `/data` or a path below it, with no `.` or `..` part and no extra `/`.
       The container also stops if the path goes through a symbolic link that
@@ -567,16 +481,9 @@ What the [upaas](https://git.eeqj.de/sneak/upaas) app for netwatch needs:
       stops the container. Empty, the backend sends nothing to Sentry
 - **Health check:** the image's `HEALTHCHECK` requests
   `/.well-known/healthcheck` through nginx every 30 seconds, so it fails unless
-  both nginx and the backend answer. It also fails while reports cannot be
+  both nginx and the backend answer. upaas reads the container's health 60
-  stored, as when the volume is full or `DATA_DIR` cannot be written: the health
+  seconds after a deploy and fails the deploy unless it is `healthy`. The
-  check answers 503 from a failed write of a report file until a write succeeds,
+  container also stops when either process exits.
-  and the backend tries the write again every minute. Three failed checks in a
-  row make the container `unhealthy`, and one that passes makes it `healthy`
-  again. upaas reads the container's health once, 60 seconds after a deploy, and
-  fails the deploy unless it is `healthy`. A container that turns `unhealthy`
-  after that is neither restarted nor reported by upaas, whose `unless-stopped`
-  restart policy ignores health; only `docker ps` and `docker inspect` show it.
-  The container also stops when either process exits.
 
 ## Browser Compatibility
 

REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-10-18
+last_modified: 2026-10-04
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -54,39 +54,34 @@ style conventions are in separate documents:
   `cibuild`. `script/bootstrap` installs all dependencies idempotently and
   assumes nothing is present: base tools come from nix, apt, brew, or apk
   (detected in that order; apt runs noninteractive). For node it uses the
-  installed node only when its major version is the pinned one; otherwise (node
+  installed node if present; otherwise it installs a PINNED node version via
-  missing, or another major, such as the node 24 the CI runner image ships) it
+  nvm, first installing nvm itself if missing — from a hash-verified GitHub
-  installs the PINNED node version via nvm and installs yarn and the packages
+  release archive (never `curl | sh`), with bash installed as an explicit
-  under it. nvm itself is installed first if missing, from a hash-verified
+  prerequisite since nvm requires bash. yarn is then pinned via
-  GitHub release archive (never `curl | sh`), with bash installed as an explicit
+  `corepack prepare yarn@<version> --activate`. Never install "latest" or "lts";
-  prerequisite since nvm requires bash. Only the major version is compared
+  always exact versions. `script/cibuild` runs the CI build: it changes to the
-  because the `Dockerfile` stages start from a node image whose exact version is
+  repo root, runs `script/bootstrap`, runs `script/check`, and builds the image
-  not the pin, and nvm cannot install a prebuilt node on alpine. yarn is pinned
+  with the version; the Gitea workflow calls it. **`script/cibuild` runs
-  via `corepack prepare yarn@<version> --activate`. Never install "latest" or
-  "lts"; always exact versions. `script/cibuild` runs the CI build: it changes
-  to the repo root, runs `script/bootstrap`, runs `script/check`, and builds the
-  image with the version; the Gitea workflow calls it. **`script/cibuild` runs
   `script/bootstrap` first**, because the workflow checks out the repo and runs
   nothing else, while `script/fmt-check` runs the formatter on the host: on a
   pristine checkout with nothing installed the run dies there, after the
-  containerised gates have passed. **The bootstrap alone is not enough**: when
+  containerised gates have passed. **The bootstrap alone is not enough**:
-  `script/bootstrap` installs node and yarn under nvm it leaves neither on the
+  `script/bootstrap` installs node and yarn under nvm and leaves neither on the
-  `PATH` of the shell that called it, so a bare `yarn` either exits 127 or runs
+  `PATH` of the shell that called it, so a bare `yarn` still exits 127. The host
-  under another node. The host entrypoints that need yarn — `script/fmt` and
+  entrypoints that need yarn — `script/fmt` and `script/fmt-check` — therefore
-  `script/fmt-check` — therefore use the same test as `script/bootstrap`: when
+  source nvm for the pinned node version before invoking it, exactly as
-  the node on `PATH` has the pinned major version they run the `yarn` on `PATH`,
+  `script/bootstrap`'s own install step does. A runner carrying nothing but
-  and otherwise they load nvm through `$HOME/.nvm/nvm.sh` and run yarn under the
+  docker and git then gets through `script/check`. Four further scripts are our
-  pinned node. A runner carrying nothing but docker and git then gets through
+  own extensions to the standard: `script/check` runs `script/test`,
-  `script/check`. Four further scripts are our own extensions to the standard:
+  `script/lint` and `script/fmt-check`; `script/precommit` is what the git
-  `script/check` runs `script/test`, `script/lint` and `script/fmt-check`;
+  pre-commit hook runs, and it calls `script/check`; `script/install-precommit`
-  `script/precommit` is what the git pre-commit hook runs, and it calls
+  installs the git pre-commit hook (the `make hooks` target shims to it); and
-  `script/check`; `script/install-precommit` installs the git pre-commit hook
+  `script/projectname` (literally that filename) simply outputs the project's
-  (the `make hooks` target shims to it); and `script/projectname` (literally
+  name. Scripts that need the name call `script/projectname` — e.g.
-  that filename) simply outputs the project's name. Scripts that need the name
+  `script/docker` assembles its image tag from it — so those scripts stay
-  call `script/projectname` — e.g. `script/docker` assembles its image tag from
+  byte-identical across all repos. Repo-type-specific pre-commit extras (e.g.
-  it — so those scripts stay byte-identical across all repos. Repo-type-specific
+  `go mod tidy` verification in Go repos) belong in `script/precommit`, not in
-  pre-commit extras (e.g. `go mod tidy` verification in Go repos) belong in
+  the hook itself. Model scripts are at
-  `script/precommit`, not in the hook itself. Model scripts are at
   `https://git.eeqj.de/sneak/prompts/raw/branch/main/script/<name>`. The README
   must document the provided scripts in an **Entrypoints** section (see the
   README requirements below).
@@ -123,10 +118,8 @@ style conventions are in separate documents:
   and nothing else:
 
     ```sh
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache --target lint -t "$(script/projectname)-lint" .
-        --target lint --output type=cacheonly .
+    docker build --no-cache --target test -t "$(script/projectname)-test" .
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
-        --target test --output type=cacheonly .
     ```
 
     **A stage that is not the last one in the file is built only when the final
@@ -136,15 +129,10 @@ style conventions are in separate documents:
     plain `docker build .` builds the last stage alone and exits 0 having linted
     and tested nothing.
 
-    **The gate builds write no image.** With `--output type=cacheonly` the phase
+    **Every `docker build` in `script/` is tagged**, here and in
-    runs and a failing step fails the build, but the result is not exported.
+    `script/cibuild` and `script/docker`. An untagged build leaves a dangling
-    Nothing uses those images, and writing one out is slow: a Go test phase's
+    image behind on every invocation, on every developer host and every CI
-    image holds the toolchain. A build given neither `--output` nor `-t` writes
+    runner; a tagged one replaces the previous image.
-    an untagged image and leaves it dangling, on every developer host and every
-    CI runner. `script/cibuild` and `script/docker` build the image that ships
-    and tag it, so each build replaces the previous image; each assigns the tag
-    on its own line before the build, so `set -e` stops it where
-    `script/projectname` fails.
 
     Inside a phase the tool is invoked directly — `golangci-lint`, `go test`,
     `eslint`, `prettier` — never through `make lint` or `script/test`, which are
@@ -159,42 +147,22 @@ style conventions are in separate documents:
     one's findings, and a host-global lock in `$TMPDIR` makes concurrent runs
     exit non-zero with `parallel golangci-lint is running` — a status a caller
     cannot tell from real findings. Both have produced wrong verdicts in this
-    org, in both directions. A container has its own `TMPDIR`, so the lock is
+    org, in both directions. A container has its own cache, its own `TMPDIR` and
-    out of reach. The lint phase does keep golangci-lint's cache between check
+    a digest-pinned binary, so neither is reachable.
-    builds (below), but it lints every checkout at `/src`, and a finding is
-    taken from that cache only for the same files, settings and golangci-lint
-    version.
 
-- **Any build that runs checks is given a new `CACHEBUST` value.** Docker
+- **Any build that runs checks is built with `--no-cache`.** Docker invalidates
-  invalidates a `COPY` layer only when the copied content changes, so on an
+  a `COPY` layer only when the copied content changes, so on an unchanged tree
-  unchanged tree the check `RUN` is served from cache, nothing executes, and the
+  the check `RUN` is served from cache, nothing executes, and the build still
-  build still exits 0. Every `docker build` in `script/` therefore passes
+  exits 0. Every `docker build` in `script/` therefore passes `--no-cache`:
-  `--build-arg CACHEBUST="$(date +%s)-$$"`, the time and the script's process
+  `script/lint`, `script/test`, `script/cibuild` and `script/docker` are the
-  id, so no two builds share a value, not even the three in one
+  four, and there is no fifth — `script/check` runs the two gate phases and
-  `script/cibuild`. `script/lint`, `script/test`, `script/cibuild` and
+  `script/fmt-check`, and builds no image of its own. A bare `docker build .` is
-  `script/docker` are the four, and there is no fifth — `script/check` runs the
+  not evidence that anything ran: a sub-second build reporting success is a
-  two gate phases and `script/fmt-check`, and builds no image of its own. In
+  cache hit, not a result. Never invalidate by pruning — `docker builder prune`
-  every stage of the `Dockerfile`, `ARG CACHEBUST` comes right after the steps
+  and friends destroy a build cache shared with every other build on the host.
-  that install system packages and download Go's modules, or right after `FROM`
+  When a check is added or changed, prove it works by planting a defect it must
-  in a stage with neither, and every step that lints, tests or compiles comes
+  catch and watching the run fail on it, then revert the defect. A green run
-  after it. A step that installs anything else as well, such as a
+  alone shows neither that the check ran nor that it covers what it should.
-  `script/bootstrap` that also installs node packages, comes after it too. A new
-  value reruns every `RUN` step after that line; `COPY` steps are compared by
-  content and need nothing. Docker keeps the layers above the line until the
-  base image, their own lines or the files they copy change. A stage without the
-  `ARG` line is served from cache on an unchanged tree, so a repository
-  re-vendors the scripts and adds the `ARG` lines in one commit. The scripts do
-  not pass `--no-cache`: it reruns every step too, but it also builds the layers
-  above the line again and empties every cache mount, so Go's build cache and
-  golangci-lint's, which the canonical Go `Dockerfile` below mounts so that they
-  survive between check builds, would start empty every time. A bare
-  `docker build .` is not evidence that anything ran: a sub-second build
-  reporting success is a cache hit, not a result. Never invalidate by pruning —
-  `docker builder prune` and friends destroy a build cache shared with every
-  other build on the host. When a check is added or changed, prove it works by
-  planting a defect it must catch and watching the run fail on it, then revert
-  the defect. A green run alone shows neither that the check ran nor that it
-  covers what it should.
 
 - **The gate phases are separate stages, and the build stage depends on both.**
   The lint phase is based on the `golangci/golangci-lint` image (pinned by
@@ -203,56 +171,40 @@ style conventions are in separate documents:
   `Dockerfile`:
 
     ```dockerfile
-    # In every stage ARG CACHEBUST comes right after the steps that install
-    # system packages and download Go's modules, or right after FROM in a
-    # stage with neither, and every step that lints, tests or compiles
-    # comes after it. script/ passes a new value on every build, which
-    # reruns every RUN step after it. Docker keeps the layers above it
-    # until the base image, their own lines or go.mod and go.sum change.
-    # The steps that compile mount Go's build cache, and golangci-lint run
-    # also mounts golangci-lint's; both survive from build to build.
-
     # Lint phase
     # golangci/golangci-lint:v2.x.x, YYYY-MM-DD
     FROM golangci/golangci-lint@sha256:... AS lint
     WORKDIR /src
     COPY go.mod go.sum ./
     RUN go mod download
-    ARG CACHEBUST
     COPY . .
-    RUN --mount=type=cache,target=/root/.cache/go-build \
+    RUN golangci-lint run --config .golangci.yml ./...
-        --mount=type=cache,target=/root/.cache/golangci-lint \
-        golangci-lint run --config .golangci.yml ./...
 
     # Test phase. -race needs cgo and so a C compiler, which the Debian Go
-    # image ships and the alpine one does not. -count=1 because the mounted
+    # image ships and the alpine one does not.
-    # cache also holds test results, which go test would otherwise replay.
     # golang:1.x, YYYY-MM-DD
     FROM golang@sha256:... AS test
     WORKDIR /src
     COPY go.mod go.sum ./
     RUN go mod download
-    ARG CACHEBUST
     COPY . .
-    RUN --mount=type=cache,target=/root/.cache/go-build \
+    RUN go test -timeout 90s -race -cover ./... || \
-        go test -count=1 -timeout 90s -race -cover ./... || \
         { echo "--- Rerunning with -v for details ---"; \
-          go test -count=1 -timeout 90s -race -v ./...; exit 1; }
+          go test -timeout 90s -race -v ./...; exit 1; }
 
     # Build stage. Nothing is wanted from either phase above; the copies
-    # are what make BuildKit build them first, so nothing after them can
+    # are what make BuildKit build them first, so this stage cannot run
-    # run unless lint and test passed.
+    # unless lint and test passed.
     # golang:1.x-alpine, YYYY-MM-DD
     FROM golang@sha256:... AS builder
+    COPY --from=lint /src/go.sum /dev/null
+    COPY --from=test /src/go.sum /dev/null
     RUN apk add --no-cache git
+    # A tar-stream context keeps the sender's file owners, which git refuses.
+    RUN git config --system --add safe.directory /src
     WORKDIR /src
     COPY go.mod go.sum ./
     RUN go mod download
-    ARG CACHEBUST
-    COPY --from=lint /src/go.sum /dev/null
-    COPY --from=test /src/go.sum /dev/null
-    # A tar-stream context keeps the sender's file owners, which git refuses.
-    RUN git config --system --add safe.directory /src
     COPY . .
 
     # The VERSION build arg when one is given, otherwise
@@ -260,8 +212,7 @@ style conventions are in separate documents:
     # .git present, a version that is still empty, dev or unknown fails the
     # build: git is missing or could not read the checkout.
     ARG VERSION
-    RUN --mount=type=cache,target=/root/.cache/go-build \
+    RUN VERSION="${VERSION:-$(git describe --tags --always)}"; \
-        VERSION="${VERSION:-$(git describe --tags --always)}"; \
         if [ -e .git ]; then \
             case "$VERSION" in ""|dev|unknown) \
                 echo "version is '$VERSION' although .git is present" >&2; \
@@ -274,7 +225,6 @@ style conventions are in separate documents:
 
     # Runtime stage, and the last one
     FROM alpine@sha256:...
-    ARG CACHEBUST
     COPY --from=builder /app /usr/local/bin/app
     ENTRYPOINT ["app"]
     ```
@@ -289,26 +239,6 @@ style conventions are in separate documents:
     - Keep the runtime stage last, and if you add a stage after it, give it the
       same two copies. A plain `docker build .` builds the last stage's chain
       and nothing else.
-    - Check builds keep these, and none of them can hand back a stale result:
-        - The layers above `ARG CACHEBUST`: the system packages and Go's
-          modules. Docker installs the packages again when the base image or the
-          install line changes, and downloads the modules again when `go.mod` or
-          `go.sum` changes. Go checks every module against `go.sum` as it
-          downloads it, and no later build can change a kept layer. The modules
-          are kept in a layer rather than a cache mount because a cache mount is
-          shared by every build on the host, and Go builds from whatever files
-          it holds without checking them again (only `go mod verify` does), so a
-          file changed there would go unnoticed.
-        - Go's build cache (`/root/.cache/go-build`, where Go keeps it for
-          root), mounted on the steps that compile: `golangci-lint run`, both
-          `go test` runs and `go build`. Go reuses a compiled package only when
-          all its inputs are unchanged. The cache also holds test results, which
-          is why both `go test` runs carry `-count=1`.
-        - golangci-lint's cache (`/root/.cache/golangci-lint`, where the pinned
-          image keeps it), mounted on `golangci-lint run`. golangci-lint reuses
-          a package's findings only when the package's files and those of every
-          package it imports, `go.mod`, the linters and their settings in
-          `.golangci.yml`, and the golangci-lint version are all unchanged.
     - If the project uses `//go:embed` directives that reference build artifacts
       (e.g. a web frontend compiled in a separate stage), the lint phase must
       create placeholder files so the embed directives resolve. Example:
@@ -317,20 +247,12 @@ style conventions are in separate documents:
       in the lint phase. The `golangci/golangci-lint` image is Debian-based and
       has no `apk`, so install with `apt-get` under the Debian package name
       (`libvips-dev`, where alpine says `vips-dev`), and delete the package
-      lists in the same `RUN`, so the layer does not keep them. The test phase,
+      lists in the same `RUN`, so the layer does not keep them:
-      on the Debian Go image, installs the libraries its tests need the same
-      way. Either install goes right after `FROM`, above `ARG CACHEBUST`, so
-      Docker keeps it until the base image or the install line changes:
 
         ```dockerfile
-        FROM golangci/golangci-lint@sha256:... AS lint
         RUN apt-get update \
             && apt-get install -y --no-install-recommends libvips-dev \
             && rm -rf /var/lib/apt/lists/*
-        WORKDIR /src
-        COPY go.mod go.sum ./
-        RUN go mod download
-        ARG CACHEBUST
         ```
 
     - `.dockerignore` lets `.git` into the build context. It keeps out every git
@@ -356,39 +278,20 @@ style conventions are in separate documents:
       `.git` and the version still comes out empty, `dev` or `unknown`. A plain
       `docker build .` with no build arguments must succeed; a Dockerfile that
       refuses an empty build argument drops that refusal and keeps the argument.
-      A checkout whose `.git` is a file (a linked worktree, or a repository
-      checked out as a submodule) is the exception: that file points to a git
-      directory outside the build context, so the build cannot read the version
-      and a plain `docker build .` fails; pass the version with
-      `--build-arg VERSION=...`, as `script/docker` and `script/cibuild` already
-      do.
 
 - Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
-  runs `script/cibuild` on push, and checks out the repo as its only other step,
+  runs `script/cibuild` on push, and checks out the repo as its only other step.
-  with `persist-credentials: false`: `script/cibuild` needs no token, and
+  That script bootstraps, runs the gate phases, and then builds the image, so a
-  without it the checkout leaves the job's token in `.git/config` for every
+  successful run means every check passed; a bare `docker build .` does not
-  later step. The checkout step also sets `fetch-depth: 0`, which fetches the
-  tags `git describe` needs: by default it clones shallow with no tags, and a
-  tagged repository's CI build would stamp a bare short commit id. The
-  workflow's `concurrency` block groups runs by workflow and branch
-  (`${{ github.workflow }}-${{ github.ref }}`) with `cancel-in-progress: true`,
-  so a new push cancels the older run on the same branch, queued or running, and
-  no other: runs for replaced commits do not hold up the shared runner.
-  `script/cibuild` bootstraps, runs the gate phases, and then builds the image,
-  so a successful run means every check passed; a bare `docker build .` does not
   carry the same guarantee, because its gate phases may come from the cache. The
-  image build gets a `CACHEBUST` value of its own and so runs the gate phases a
+  image build is uncached and so runs the gate phases a second time. That is the
-  second time. That is the price of the rule above, and it is worth paying: the
+  price of the rule above, and it is worth paying: the image that ships is built
-  image that ships is built from a run of its own gates rather than from a cache
+  from a run of its own gates rather than from a cache entry. A separate
-  entry. The `check` job sets `timeout-minutes: 20`, so a hung build frees the
+  workflow limited to `main` by a `branches` list under `on: push` cannot be
-  shared runner after 20 minutes. That allows for the three Docker builds
+  checked by review: to try a change to it, add the feature branch to that list
-  described above (the test phase, the lint phase, then the image), each held to
+  and push, then remove the branch from the list again before merging. Keep any
-  the 5-minute Docker build limit below, plus the bootstrap. A separate workflow
+  job in it that publishes behind `if: github.ref_name == 'main'`, so the run
-  limited to `main` by a `branches` list under `on: push` cannot be checked by
+  from the feature branch publishes nothing.
-  review: to try a change to it, add the feature branch to that list and push,
-  then remove the branch from the list again before merging. Keep any job in it
-  that publishes behind `if: github.ref_name == 'main'`, so the run from the
-  feature branch publishes nothing.
 
 - Use platform-standard formatters: `black` for Python, `prettier` for
   JS/CSS/Markdown/HTML, `go fmt` for Go. Always use default configuration with
@@ -448,11 +351,12 @@ style conventions are in separate documents:
     That cache is Go's own, separate from Docker's layer cache. Go stores a
     passing result in its cache directory (`GOCACHE`), and when the same tests
     run again on unchanged code it prints that result, marked `(cached)`,
-    without running them. The directory lasts from one run to the next on a
+    without running them. That matters on a developer's machine, where this
-    developer's machine, where this target runs, and in the `test` phase of the
+    target runs and the directory lasts from one run to the next. The `test`
-    `Dockerfile`, which mounts it to keep compiled packages between check
+    phase of the `Dockerfile` needs no `-count=1`: its base image holds no
-    builds, so the phase's `go test` runs carry `-count=1` too. A new
+    result for this repo's tests and nothing before its `go test` step runs a
-    `CACHEBUST` value (above) is what makes that step run on an unchanged tree.
+    test, so there is nothing to replay. `--no-cache` (above) is what makes that
+    step run on an unchanged tree.
 
     Python example:
 
@@ -480,12 +384,9 @@ style conventions are in separate documents:
 
 - `.gitignore` should be comprehensive from the start: OS files (`.DS_Store`),
   editor files (`.swp`, `*~`), in-repo agent scratch directories (`.claude/`),
-  `node_modules/`, and the repo's own build outputs. Fetch the standard
+  language build artifacts, and `node_modules/`. Fetch the standard `.gitignore`
-  `.gitignore` from
+  from `https://git.eeqj.de/sneak/prompts/raw/branch/main/.gitignore` when
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.gitignore` when setting up
+  setting up a new repo. These patterns are written to `.gitignore`'s own
-  a new repo. A repo's `.gitignore` is the standard file followed by the repo's
-  own entries, such as its binaries; a re-vendor replaces the standard part and
-  keeps those entries. These patterns are written to `.gitignore`'s own
   semantics, in which an unanchored pattern already matches at every depth; they
   are not a `.dockerignore` and must not be transplanted into one unmodified.
 
@@ -533,15 +434,13 @@ style conventions are in separate documents:
   byte-identically across repos:
 
     ```sh
-    # The version and the tag each get their own line: a failing command
+    # Own line: a failing command substitution inside an argument does not
-    # substitution inside an argument does not trip `set -e`, so the inline
+    # trip `set -e`, so the inline form degrades to an empty constant.
-    # form degrades to an empty constant.
     version="$(git describe --tags --always --dirty 2>/dev/null || true)"
     [ -n "$version" ] || version="unknown"
-    tag="$(script/projectname)"
+    docker build --no-cache \
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
         --build-arg VERSION="$version" \
-        -t "$tag" .
+        -t "$(script/projectname)" .
     ```
 
     `--always` makes an untagged repo yield an abbreviated commit hash rather
@@ -553,8 +452,8 @@ style conventions are in separate documents:
     there because `ARG` is stage-scoped; passing `VERSION` to a repo whose
     Dockerfile declares no such `ARG` is ignored and costs nothing, which is why
     the scripts stay byte-identical. One consequence for CI: the standard
-    checkout action clones shallow and fetches no tags, so the canonical
+    checkout action clones shallow and fetches no tags, so a repo that embeds a
-    `.gitea/workflows/check.yml` sets `fetch-depth: 0` on its checkout step.
+    tag-derived version must set `fetch-depth: 0` on its checkout step.
 
 - **Verify `.dockerignore` by enumerating the image, not by reading the
   patterns.** Plant files at the root _and_ at least two directories deep, build
@@ -621,11 +520,6 @@ style conventions are in separate documents:
       function defined and never invoked has the same exit status and the same
       empty output as one that worked.
 
-    Node is the exception to the whole-token comparison: the canonical
-    `script/bootstrap` compares only its major version, because the node 22
-    alpine image the `Dockerfile` stages start from is not the exact pin, and
-    nvm cannot install a prebuilt node on alpine.
-
     Keep it POSIX sh: no arrays, no `[[`, no `grep -P`.
 
     A Go tool a repo needs on the host is installed with `go install` pinned to
@@ -742,11 +636,7 @@ style conventions are in separate documents:
       Never edit existing migrations after release.
 
 - All repos should have an `.editorconfig` enforcing the project's indentation
-  settings: the standard file from
+  settings.
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.editorconfig`, which sets
-  tabs for `Makefile` and Go files, followed by the repo's own sections, such as
-  one for another language it uses. A re-vendor replaces the standard part and
-  keeps those sections.
 
 - Avoid putting files in the repo root unless necessary. Root should contain
   only project-level config files (`README.md`, `AGENTS.md`, `Makefile`,

TODO.md

@@ -9,12 +9,10 @@
 
 # Status
 
-pre-1.0. Release candidates are tagged on `next`, the first being `v1.0.0-rc1`;
+pre-1.0. No git tags. `main` is the stable branch and `next` the development
-`git tag --merged origin/next` lists them. `main` is the stable branch and
+branch, which every PR targets. The frontend and the Go backend ship as one
-`next` the development branch, which every PR targets. The frontend and the Go
+Docker image, and the Gitea workflow `.gitea/workflows/check.yml` runs
-backend ship as one Docker image, and the Gitea workflow
+`script/cibuild` on every push. Working toward 1.0.0.
-`.gitea/workflows/check.yml` runs `script/cibuild` on every push, and cancels
-the older run on the same branch. Working toward 1.0.0.
 
 # Next Step
 
@@ -23,269 +21,6 @@ Run `make frontend-viewport-test` in CI as its own step; it is not part of
 
 # Completed Steps
 
-- 2026-10-19: the server's `OnStart` hook in `internal/server/server.go` starts
-  `listenAndServe` with `go func() { s.listenAndServe() }()`, as the Go style
-  guide asks ([#162](https://git.eeqj.de/sneak/netwatch/issues/162)); it was
-  `go s.listenAndServe()`. No other `go` statement in the Go code called a
-  function directly. Nothing the server does changed
-- 2026-10-19: `.gitignore`, `.editorconfig` and `.golangci.yml` are the
-  sneak/prompts copies at `0653579`
-  ([#174](https://git.eeqj.de/sneak/netwatch/issues/174)). `.gitignore` is the
-  standard file followed by this repository's own entries; `.editorconfig` is
-  the standard file alone, which now carries the `[*.go]` section.
-  `.golangci.yml` disables `canonicalheader`, as the canonical copy does,
-  because golangci-lint v2.14.0 misses its findings at random
-- 2026-10-19: `package.json` has no `version` field and is marked
-  `"private": true` ([#158](https://git.eeqj.de/sneak/netwatch/issues/158)). It
-  said `1.0.0`, a release that has not been made, and nothing read it; the git
-  tag is the one version, which the image and `make build` take from
-  `git describe --tags`. The package is never published
-- 2026-10-19: Status names `v1.0.0-rc1`, the first release candidate, and says
-  release candidates are tagged on `next`, where it said there were no git tags
-  ([#157](https://git.eeqj.de/sneak/netwatch/issues/157)). The rest of Status
-  matches the tree
-- 2026-10-19: `netwatch-server` starts the server only when given no arguments
-  ([#179](https://git.eeqj.de/sneak/netwatch/issues/179)). `check-cidr CIDR` and
-  `prepare-data-dir DATA_DIR` behave as before; any other arguments, such as a
-  subcommand with no value or two, or a misspelt one, print a one-line usage
-  message naming both forms to stderr and exit 2. They used to start the server.
-  Unit tests call `cli.Main` with no arguments and check that it starts the
-  server, and with each subcommand given no value and two values and with a
-  misspelt subcommand, and check the exit code, the message and that the server
-  does not start
-- 2026-10-19: `main()` in `cmd/netwatch-server/main.go` is one call into a new
-  package, `internal/cli`, as the Go style guide asks
-  ([#160](https://git.eeqj.de/sneak/netwatch/issues/160)). `internal/cli` runs
-  the `check-cidr` and `prepare-data-dir` subcommands, with the same arguments,
-  messages and exit codes, and otherwise the server, with the `fx` wiring.
-  `Appname` and `Version` stay in `main`, where the build sets `Version`, and
-  `main` gives `cli.Main` stderr and the function that runs the server, which
-  the tests replace with a buffer and a function that fails them. Unit tests
-  call `cli.Main` with `check-cidr` and a CIDR the server takes and one it
-  refuses, and check the exit code and what it writes to stderr, and with
-  `prepare-data-dir` and a path outside `/data`, and check that it exits 1 with
-  the error from looking up the `netwatch` user, which the test image does not
-  have. Others give the functions behind the subcommands input they take and
-  input they refuse, and check the exit code and what they write to stderr
-- 2026-10-19: when `VERSION` is unset or empty, `script/build` stamps the
-  version from `git describe --tags --always --dirty`, as `script/docker` does
-  ([#156](https://git.eeqj.de/sneak/netwatch/issues/156)). Without `--tags` it
-  skipped lightweight tags, so `make run` could report a commit where the image
-  built from the same tree reported the tag. Checked once with a lightweight tag
-  on a scratch clone: `make build` stamped it
-- 2026-10-19: `.dockerignore` keeps Go test binaries and coverage output at the
-  root out of the build context, with `/*.test` and `/*.out` in the repository's
-  own section ([#155](https://git.eeqj.de/sneak/netwatch/issues/155)). Such
-  files went into the build context of every `docker build` in `script/` and
-  were copied into the lint, test and build stages. Checked with a probe image
-  that copies the whole context: `x.test` and `x.out` planted at the root no
-  longer land in it, and nothing else changed. The entries match only at the
-  root, so the same files in a subdirectory still reach the image
-- 2026-10-19: `.gitea/workflows/check.yml` is the sneak/prompts copy at
-  `0653579` ([#153](https://git.eeqj.de/sneak/netwatch/issues/153)). Its
-  checkout step sets `fetch-depth: 0`, so CI clones all history and tags, and
-  `git describe` in `script/cibuild` gives the image built from a tagged commit
-  the tag as its version; it gave the short commit. The checkout step also sets
-  `persist-credentials: false`, so the job's token is not left in `.git/config`.
-  A new push cancels the older run on the same branch, and a run stops after 20
-  minutes
-- 2026-10-19: `script/bootstrap` keeps the `yarn` on `PATH` only when
-  `yarn --version` is exactly `YARN_VERSION`, and otherwise installs that
-  version as it did when no yarn was installed
-  ([#154](https://git.eeqj.de/sneak/netwatch/issues/154)); any yarn used to be
-  kept. It uses the `node` on `PATH` only when that node has the major version
-  of `NODE_VERSION`, as `REPO_POLICIES.md` asks, and is at least
-  `NODE_MIN_VERSION`; a node 24 was kept before. After installing node or yarn
-  it looks the tool up through `PATH` again and stops if that one fails the same
-  check, as it does for Go, and it prints the node and yarn versions it uses.
-  Every script that runs yarn on the host, except `script/bootstrap`, which
-  picks its own node and yarn, runs it through the new `script/yarn`. That
-  script puts `~/.local/bin` first on `PATH`, uses the first `node` on that
-  `PATH` when it passes the same test, and otherwise runs yarn under the pinned
-  node in nvm; `make build` ran yarn under whatever node was first on `PATH`
-- 2026-10-19: `bin/entrypoint.sh` has each of its steps in a function, and a
-  `main` at the end calls them in order, as the shell section of the code style
-  guide asks ([#163](https://git.eeqj.de/sneak/netwatch/issues/163)). It is
-  still POSIX sh with no `set -e`, and does what it did, with the same messages
-  and exit codes. Checked by running the image with each script: a normal start,
-  bad `PORT`, `TRUSTED_PROXIES` and `DATA_DIR` values, `docker stop`, INT, and
-  nginx exiting on its own
-- 2026-10-19: while report files cannot be written, the health check answers 503
-  with `"status":"error"` and the same fields, so the image's `HEALTHCHECK`
-  reports the container `unhealthy`
-  ([#142](https://git.eeqj.de/sneak/netwatch/issues/142)). It answered 200
-  `"status":"ok"` whatever happened, so the platform saw a healthy container
-  while every report was refused with 500. It answers 200 at start, before any
-  write has failed, and again from the first write that succeeds. A unit test
-  removes `DATA_DIR` to make a write fail and checks the 503, then puts it back
-  and checks the 200 after the next write
-- 2026-10-19: report file writes no longer overlap
-  ([#150](https://git.eeqj.de/sneak/netwatch/issues/150)), so the reports of
-  failed writes are written in the order they arrived. Two writes that failed at
-  the same time put their reports back in the wrong order when the older failed
-  first. One write runs at a time, and each takes the waiting reports only when
-  it starts, after a failed write has put its own back. The write `Append`
-  starts when 10 MiB are waiting waits for any write under way, and `Append`
-  starts no other while it waits. Files written since the start are deleted to
-  make room in the order they were written, after those found at start. A unit
-  test holds a write open, starts a second at 10 MiB, fails both and checks the
-  order in the next file. Others check that `Append` starts no second write at
-  10 MiB while one waits, that it starts one again the next time 10 MiB are
-  waiting, and that the first file written since the start is the first deleted
-- 2026-10-19: `DEBUG` unset or empty leaves debug logging off, and any other
-  value, `false` and `0` included, turns it on, as the code style guide says
-  ([#159](https://git.eeqj.de/sneak/netwatch/issues/159)). No value of it stops
-  the start any more; before, only `1`, `t`, `T`, `TRUE`, `true`, `True`, `0`,
-  `f`, `F`, `FALSE`, `false` and `False` were accepted. `README.md` no longer
-  gives `false` as its default
-- 2026-10-19: check builds keep Go's modules and compiled packages between runs
-  ([#118](https://git.eeqj.de/sneak/netwatch/issues/118)), on sneak's rulings in
-  [prompts#113](https://git.eeqj.de/sneak/prompts/issues/113) and
-  [prompts#130](https://git.eeqj.de/sneak/prompts/issues/130).
-  `REPO_POLICIES.md`, `script/test`, `script/lint`, `script/docker` and
-  `script/cibuild` are the sneak/prompts copies at `0653579`: the scripts pass a
-  new `CACHEBUST` value where they passed `--no-cache`, and the lint and test
-  builds write no image. In each stage of `Dockerfile`, `ARG CACHEBUST` comes
-  after the system packages and the Go module download, and before every step
-  that lints, tests or compiles and the node stages' `yarn install`. Go's build
-  cache and golangci-lint's are cache mounts, and both `go test` runs carry
-  `-count=1`. The test phase's Go caches used to be in memory, empty on every
-  build
-- 2026-10-19: the three unit tests of a check whose result is discarded (its
-  round given up, the user paused, or the first round) also check that the
-  host's history is still empty, its status still `pending`, and nothing was
-  written to the console
-  ([#151](https://git.eeqj.de/sneak/netwatch/issues/151)). They checked only the
-  row, so a change that recorded the result and skipped only the row would have
-  kept them passing
-- 2026-10-18: when the backend runs on its own, a `DATA_DIR` that cannot be
-  created or read, or where no file can be created, stops the start with an
-  error naming `DATA_DIR` and its value, as the other settings' errors do
-  ([#148](https://git.eeqj.de/sneak/netwatch/issues/148)); the first two named
-  only the path, and the third was found only at the first write of a report
-  file. At start the server creates a file in `DATA_DIR` and removes it. Unit
-  tests start the buffer with `DATA_DIR` below a regular file and with
-  `DATA_DIR` set to `/proc`, and check the error. The report file number is an
-  `atomic.Int64`, as the Go style guide asks for int types
-  ([#161](https://git.eeqj.de/sneak/netwatch/issues/161)); file names are
-  unchanged
-- 2026-10-18: the image's nginx sends the page with `Cache-Control: no-cache`
-  ([#141](https://git.eeqj.de/sneak/netwatch/issues/141)), so a browser that
-  keeps a copy checks with the server that it is current before using it again.
-  The page went out with no `Cache-Control`, so a browser could keep it after a
-  deploy and ask for files under `/assets/` that the new build no longer has,
-  and show an empty page. A path that `location /` answers with the page through
-  its `try_files` fallback gets the same header. `location /` now includes the
-  security headers again, as `/assets/` does, since its own `add_header` drops
-  the server's. `/assets/` keeps its immutable caching.
-  `make frontend-viewport-test` fails unless `/` and a path that falls back to
-  the page carry `Cache-Control: no-cache` and `Content-Security-Policy`, which
-  comes from the same file as the other security headers
-- 2026-10-18: `README.md` says what the page loses while reports are refused or
-  the page is paused ([#145](https://git.eeqj.de/sneak/netwatch/issues/145)),
-  how fast one address can replace the stored reports
-  ([#146](https://git.eeqj.de/sneak/netwatch/issues/146)), and that in the image
-  nginx answers a body over 1 MiB itself
-  ([#147](https://git.eeqj.de/sneak/netwatch/issues/147)). A sample in the
-  history that no report has delivered is sent only as long as the history holds
-  it: at the 1-second interval one refused or failed report loses the oldest 20
-  seconds of each host's samples, and a pause longer than the history loses
-  every sample between the last delivered report and the pause. Samples an
-  interval change cleared are kept apart, the last 100 per host, until they are
-  delivered. At the defaults, one address sending 1 MiB reports made up to
-  compress badly can fill the 1 GiB cap in about 17 minutes. nginx's
-  `client_max_body_size` is also 1 MiB by default, so in the image it answers a
-  larger body with 413 and its own HTML page, and the backend never sees or
-  records it; the backend's own 413 sentences now say they apply to it run on
-  its own. The reporter, the body limit and nginx are unchanged
-- 2026-10-18: a browser that cannot format the header's clocks still probes
-  ([#149](https://git.eeqj.de/sneak/netwatch/issues/149)). The clocks name the
-  local time zone through `Intl.DateTimeFormat`'s `shortGeneric` option, which
-  Chrome before 95, Firefox before 91 and Safari before 15.4 reject with an
-  error; it came before the first round started, so such a browser never checked
-  a target. The clocks now start last, after the rounds, and an error formatting
-  them leaves both blank. The footer's color legend reads `>=500ms` for red,
-  where it read `>500ms`, so 500 ms, which is red, is in one of its colors
-  ([#152](https://git.eeqj.de/sneak/netwatch/issues/152)). Unit tests check the
-  clocks with a working `Intl.DateTimeFormat` and with one that rejects
-  `shortGeneric`, and draw the page and check the legend against every entry of
-  `CONFIG.latencyColors`
-- 2026-10-18: `netwatch-server prepare-data-dir` no longer changes the owner of
-  a file outside `/data` through a hard link in the volume
-  ([#143](https://git.eeqj.de/sneak/netwatch/issues/143)). A file with a second
-  name (hard link) keeps its owner, and the start logs its path. Owners are now
-  set on the opened directory, file or link, never by name, so a hard link
-  swapped in after the check is caught too; a symbolic link is opened without
-  following it and given to the netwatch user itself, so the server can still
-  follow one in a sticky directory that anyone can write to. Devices, named
-  pipes and sockets keep their owner. Setting the owner on an open file that is
-  not a directory is built only for Linux: `prepare-data-dir` runs only in the
-  Linux image, and macOS, where the backend is also built for development, has
-  neither `O_PATH` nor `AT_EMPTY_PATH`. On any other system the package still
-  builds, and `prepare-data-dir` fails at the first file that is not a
-  directory. The test that runs as root hard-links a file, a symbolic link and a
-  named pipe from outside the volume into it and finds their owners unchanged
-- 2026-10-18: from a trusted proxy, the backend takes the client address from
-  the right-most `X-Forwarded-For` entry that is not in `TRUSTED_PROXIES`
-  ([#144](https://git.eeqj.de/sneak/netwatch/issues/144)). It took the left-most
-  entry, which the client writes itself behind a proxy that appends to the
-  header, so a client could choose the address the rate limit counts and the
-  request log records. An entry written as an address with a port is read as
-  that address. With only trusted addresses in the header, or an entry that is
-  not an address at all (such as `unknown`) met on the way, the direct peer is
-  used. `X-Real-IP` is read only without `X-Forwarded-For`, and every
-  `X-Forwarded-For` header line is read, not only the first. The image's nginx,
-  and the `TRUSTED_PROXIES=127.0.0.1/32` it starts the backend with, are
-  unchanged; the comment in `configs/nginx.conf` that said the backend takes the
-  first entry now says it takes the one address nginx passes on. Unit tests
-  resolve the address from chains ending in an untrusted address, in trusted
-  ones, of only trusted ones, with ports, with an entry that is not an address,
-  and split over two header lines
-- 2026-10-18: after an interval change, the summary's Reachable slot reads
-  `--/--` in white, as at page load, until the second round since the change
-  ends ([#140](https://git.eeqj.de/sneak/netwatch/issues/140)). It used to read
-  0/26 in red from the change on, as no WAN host had a check recorded, for up to
-  two intervals with the network fine. The summary update now writes `--/--`
-  while every WAN host still waits for its first check. A unit test resets the
-  hosts as the interval menu does and checks the slot; another checks that it
-  reads 0/26 in red once every WAN host's check has failed
-- 2026-10-14: stopping the server waits for a report file write already under
-  way, the periodic flush's or the one `Append` starts when 10 MiB are waiting,
-  before the final flush
-  ([#122](https://git.eeqj.de/sneak/netwatch/issues/122)). It used to return at
-  once, and the process exiting cut the write off, losing its reports. A write
-  under way that fails puts its reports back in memory, so the final flush
-  writes them; the stop fails, and the process exits non-zero, only if that
-  flush fails too. Two tests hold the periodic write and the one at 10 MiB open
-  and find the stop waiting until each is released; a third makes the held write
-  fail and finds its report written by the final flush. They run in a
-  `testing/synctest` bubble, so the periodic flush comes without waiting a
-  minute
-- 2026-10-14: `make test` no longer runs the frontend's production build, which
-  the tests do not need ([#118](https://git.eeqj.de/sneak/netwatch/issues/118)).
-  `yarn build` moved out of the stage that runs the frontend's unit tests, now
-  named `frontend-test`, into a new `frontend-build` stage, which starts from it
-  and, like the `builder` stage, waits on the lint and test phases, so the image
-  still cannot be built unless they pass. The runtime stage copies `dist/` from
-  it, and the `git` that `vite.config.js` reads the commit with is installed
-  there. No build cache was added
-- 2026-10-14: opening the debug log no longer raises the measured latencies
-  ([#131](https://git.eeqj.de/sneak/netwatch/issues/131)). With the panel open,
-  each line written drew the panel again with every line before it, up to 1000,
-  and a check that ends while the page draws is timed only when the drawing is
-  done. Each line is now added at the end of the open panel, its first line is
-  dropped once it holds more than 1000, and it scrolls to its newest line once a
-  frame rather than once a line; the whole panel is drawn only when it is
-  opened. A unit test writes more lines than the panel keeps and checks that the
-  lines already shown are left as they are
-- 2026-10-14: unset, the backend's own `TRUSTED_PROXIES` trusts `10.0.0.0/8`,
-  `172.16.0.0/12` and `192.168.0.0/16`, and no longer loopback; a list replaces
-  that; set and empty, it trusts no proxy, where it used to get the default, as
-  viper reads an empty environment variable as unset
-  ([#129](https://git.eeqj.de/sneak/netwatch/issues/129)). A value it cannot
-  parse still stops the start, and the image still starts the backend with
-  `TRUSTED_PROXIES=127.0.0.1/32`. Tests load the config with it unset, empty and
-  set to a list
 - 2026-10-14: while report files cannot be written, `POST /api/v1/reports`
   answers 500, and storing recovers once writing works again, with no restart
   ([#123](https://git.eeqj.de/sneak/netwatch/issues/123)). A failed write puts

bin/entrypoint.sh

@@ -13,27 +13,24 @@ set -u
 # address and start anyway, and reports a bad port without naming
 # PORT, so a value that is not a usable port stops the container here,
 # before either process starts.
-check_port() {
+export PORT="${PORT:-8080}"
-    export PORT="${PORT:-8080}"
+case "$PORT" in
-    case "$PORT" in
+    *[!0-9]*)
-        *[!0-9]*)
+        echo "entrypoint: PORT must be a port number, not '$PORT'" >&2
-            echo "entrypoint: PORT must be a port number, not '$PORT'" >&2
-            exit 1
-            ;;
-    esac
-    # The length is checked first because, for a number too big for it,
-    # the shell's test prints an error and is false, so the range checks
-    # alone would let it through.
-    if [ "${#PORT}" -gt 5 ] || [ "$PORT" -lt 1 ] || [ "$PORT" -gt 65535 ]; then
-        echo "entrypoint: PORT must be from 1 to 65535, not '$PORT'" >&2
         exit 1
-    fi
+        ;;
-    if [ "$PORT" -eq 8081 ]; then
+esac
-        echo "entrypoint: PORT cannot be 8081, netwatch-server" \
+# The length is checked first because, for a number too big for it,
-            "listens there" >&2
+# the shell's test prints an error and is false, so the range checks
-        exit 1
+# alone would let it through.
-    fi
+if [ "${#PORT}" -gt 5 ] || [ "$PORT" -lt 1 ] || [ "$PORT" -gt 65535 ]; then
-}
+    echo "entrypoint: PORT must be from 1 to 65535, not '$PORT'" >&2
+    exit 1
+fi
+if [ "$PORT" -eq 8081 ]; then
+    echo "entrypoint: PORT cannot be 8081, netwatch-server listens there" >&2
+    exit 1
+fi
 
 # TRUSTED_PROXIES names the reverse proxies in front of the container,
 # as IP addresses or CIDRs separated by commas. nginx takes the client
@@ -50,38 +47,35 @@ check_port() {
 # TRUSTED_PROXIES. Its error, naming the CIDR, is dropped for the one
 # below, naming the entry as written. set -f keeps a * in an entry from
 # becoming a list of file names.
-write_trusted_proxies() {
+TRUSTED_PROXIES="${TRUSTED_PROXIES-10.0.0.0/8,172.16.0.0/12,192.168.0.0/16}"
-    TRUSTED_PROXIES="${TRUSTED_PROXIES-10.0.0.0/8,172.16.0.0/12,192.168.0.0/16}"
+set -f
-    set -f
+for proxy in $(printf '%s' "$TRUSTED_PROXIES" | tr ',' ' '); do
-    for proxy in $(printf '%s' "$TRUSTED_PROXIES" | tr ',' ' '); do
+    case "$proxy" in
-        case "$proxy" in
+        */*) cidr="$proxy" ;;
-            */*) cidr="$proxy" ;;
+        *:*) cidr="$proxy/128" ;;
-            *:*) cidr="$proxy/128" ;;
+        *) cidr="$proxy/32" ;;
-            *) cidr="$proxy/32" ;;
+    esac
-        esac
+    if ! netwatch-server check-cidr "$cidr" 2> /dev/null; then
-        if ! netwatch-server check-cidr "$cidr" 2> /dev/null; then
+        echo "entrypoint: TRUSTED_PROXIES must be IP addresses or CIDRs" \
-            echo "entrypoint: TRUSTED_PROXIES must be IP addresses or CIDRs" \
+            "separated by commas; '$proxy' is neither" >&2
-                "separated by commas; '$proxy' is neither" >&2
+        exit 1
-            exit 1
+    fi
-        fi
+    echo "set_real_ip_from $cidr;"
-        echo "set_real_ip_from $cidr;"
+done > /etc/nginx/trusted-proxies.conf
-    done > /etc/nginx/trusted-proxies.conf
-}
 
 # netwatch-server keeps its report files in DATA_DIR, on the /data
 # volume, which may be a host directory owned by root or by another
 # uid. Here, as root, netwatch-server prepare-data-dir creates DATA_DIR
-# and gives /data and the directories, regular files and symbolic links
+# and gives /data and everything in it to the netwatch user, so the
-# in it to the netwatch user, so the host directory needs no preparing.
+# host directory needs no preparing. It stops the start, naming
-# A file with a second name (hard link) keeps its owner, as that name
+# DATA_DIR, unless DATA_DIR is /data or a path below it, and it acts on
-# could be outside /data, and its path is logged. It stops the start,
+# nothing outside /data, whatever symbolic links it meets there.
-# naming DATA_DIR, unless DATA_DIR is /data or a path below it, and it
+export DATA_DIR="${DATA_DIR:-/data/reports}"
-# acts on nothing outside /data, whatever symbolic or hard links it
+netwatch-server prepare-data-dir "$DATA_DIR" || exit 1
-# meets there.
+
-prepare_data_dir() {
+# A stop signal is only noted here; the loop below acts on it.
-    export DATA_DIR="${DATA_DIR:-/data/reports}"
+stop_requested=""
-    netwatch-server prepare-data-dir "$DATA_DIR" || exit 1
+trap 'stop_requested=yes' TERM INT
-}
 
 # netwatch-server runs as the netwatch user and listens on loopback
 # only, on a port other than the public one; configs/nginx.conf proxies
@@ -90,11 +84,9 @@ prepare_data_dir() {
 # the container has. The netwatch user has no login shell, hence -s
 # /bin/sh. busybox su replaces itself with the command instead of
 # staying on as its parent, so $! is the server's own PID.
-start_backend() {
+BIND_ADDRESS=127.0.0.1 PORT=8081 TRUSTED_PROXIES=127.0.0.1/32 \
-    BIND_ADDRESS=127.0.0.1 PORT=8081 TRUSTED_PROXIES=127.0.0.1/32 \
+    su -s /bin/sh netwatch -c 'exec netwatch-server' &
-        su -s /bin/sh netwatch -c 'exec netwatch-server' &
+backend=$!
-    backend=$!
-}
 
 # nginx starts through the nginx image's own entrypoint, which applies
 # the image's start-up configuration and then replaces itself with
@@ -103,11 +95,9 @@ start_backend() {
 # that rendering to PORT: a variable nginx itself uses, such as $uri,
 # would otherwise be replaced by an environment variable of the same
 # name.
-start_nginx() {
+NGINX_ENVSUBST_FILTER='^PORT$' \
-    NGINX_ENVSUBST_FILTER='^PORT$' \
+    /docker-entrypoint.sh nginx -g 'daemon off;' &
-        /docker-entrypoint.sh nginx -g 'daemon off;' &
+nginx=$!
-    nginx=$!
-}
 
 running() {
     kill -0 "$1" 2>/dev/null
@@ -116,47 +106,26 @@ running() {
 # POSIX sh cannot wait for whichever of two children exits first, so
 # look once a second. The shell collects a child that has exited while
 # it runs sleep, and running() is false for that child from then on.
-wait_for_stop_or_exit() {
+while [ -z "$stop_requested" ] && running "$backend" && running "$nginx"; do
-    while [ -z "$stop_requested" ] && running "$backend" && running "$nginx"; do
+    sleep 1
-        sleep 1
+done
-    done
-}
 
 # Stop both, then wait until neither is left.
-stop_both() {
+kill -TERM "$backend" "$nginx" 2>/dev/null
-    kill -TERM "$backend" "$nginx" 2>/dev/null
+while running "$backend" || running "$nginx"; do
-    while running "$backend" || running "$nginx"; do
+    sleep 1
-        sleep 1
+done
-    done
+
-}
+wait "$backend"
+backend_status=$?
+wait "$nginx"
+nginx_status=$?
+echo "entrypoint: netwatch-server exited $backend_status," \
+    "nginx exited $nginx_status"
 
 # Success is a requested stop that both processes exited cleanly from.
-exit_with_status() {
+if [ -n "$stop_requested" ] && [ "$backend_status" -eq 0 ] &&
-    wait "$backend"
+    [ "$nginx_status" -eq 0 ]; then
-    backend_status=$?
+    exit 0
-    wait "$nginx"
+fi
-    nginx_status=$?
+exit 1
-    echo "entrypoint: netwatch-server exited $backend_status," \
-        "nginx exited $nginx_status"
-    if [ -n "$stop_requested" ] && [ "$backend_status" -eq 0 ] &&
-        [ "$nginx_status" -eq 0 ]; then
-        exit 0
-    fi
-    exit 1
-}
-
-main() {
-    check_port
-    write_trusted_proxies
-    prepare_data_dir
-    # A stop signal is only noted here; wait_for_stop_or_exit acts on it.
-    stop_requested=""
-    trap 'stop_requested=yes' TERM INT
-    start_backend
-    start_nginx
-    wait_for_stop_or_exit
-    stop_both
-    exit_with_status
-}
-
-main "$@"

cmd/netwatch-server/main.go

@@ -1,11 +1,22 @@
-// Package main is the entry point for netwatch-server; package cli
+// Package main is the entry point for netwatch-server.
-// does the work.
 package main
 
 import (
+	"fmt"
 	"os"
+	"os/user"
 
-	"sneak.berlin/go/netwatch/internal/cli"
+	"sneak.berlin/go/netwatch/internal/config"
+	"sneak.berlin/go/netwatch/internal/globals"
+	"sneak.berlin/go/netwatch/internal/handlers"
+	"sneak.berlin/go/netwatch/internal/healthcheck"
+	"sneak.berlin/go/netwatch/internal/logger"
+	"sneak.berlin/go/netwatch/internal/middleware"
+	"sneak.berlin/go/netwatch/internal/reportbuf"
+	"sneak.berlin/go/netwatch/internal/server"
+
+	"go.uber.org/fx"
+	"go.uber.org/fx/fxevent"
 )
 
 //nolint:gochecknoglobals // set via ldflags at build time
@@ -15,5 +26,64 @@ var (
 )
 
 func main() {
-	os.Exit(cli.Main(os.Stderr, Appname, Version, os.Args[1:], cli.RunServer))
+	// "netwatch-server check-cidr CIDR" exits 1, with the error, if
+	// this server would refuse CIDR in its TRUSTED_PROXIES.
+	// bin/entrypoint.sh runs it on each entry it gives nginx.
+	if len(os.Args) == 3 && os.Args[1] == "check-cidr" {
+		_, err := middleware.ParseTrustedProxies(os.Args[2:])
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+
+		return
+	}
+
+	// "netwatch-server prepare-data-dir DATA_DIR" gets DATA_DIR ready
+	// for the netwatch user, or exits 1 with the error; see
+	// reportbuf.PrepareDataDir. bin/entrypoint.sh runs it as root
+	// before it starts this server as that user.
+	if len(os.Args) == 3 && os.Args[1] == "prepare-data-dir" {
+		netwatch, err := user.Lookup("netwatch")
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+
+		err = reportbuf.PrepareDataDir("/data", os.Args[2], netwatch)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "DATA_DIR '%s': %v\n", os.Args[2], err)
+			os.Exit(1)
+		}
+
+		return
+	}
+
+	globals.Appname = Appname
+	globals.Version = Version
+
+	fx.New(
+		// fx logs each step of starting and stopping through the
+		// server's own logger, so off a terminal those lines are
+		// JSON like every other line.
+		fx.WithLogger(func(log *logger.Logger) fxevent.Logger {
+			return &fxevent.SlogLogger{Logger: log.Get()}
+		}),
+		fx.Provide(
+			config.New,
+			globals.New,
+			handlers.New,
+			healthcheck.New,
+			logger.New,
+			middleware.New,
+			reportbuf.New,
+			server.New,
+		),
+		fx.Invoke(
+			// First, so the name and version are logged even when
+			// a setting stops the start.
+			func(log *logger.Logger) { log.Identify() },
+			func(*server.Server) {},
+		),
+	).Run()
 }

configs/nginx.conf

@@ -30,13 +30,8 @@ server {
     access_log /dev/stdout combined;
     error_log  /dev/stderr warn;
 
-    # With no-cache, a browser never uses a copy of the page that names
-    # assets a newer build no longer has without first checking with the
-    # server that it is current.
     location / {
         try_files $uri $uri/ /index.html;
-        add_header Cache-Control no-cache;
-        include /etc/nginx/security-headers.conf;
     }
 
     # Cache static assets aggressively
@@ -51,9 +46,7 @@ server {
     # 127.0.0.1:8081. These headers go with every request passed to it.
     # X-Forwarded-For carries only the client address, as resolved by
     # the real IP settings above, and not the chain the request came
-    # with. bin/entrypoint.sh starts the backend with
+    # with: the backend takes the first entry, which a client can write.
-    # TRUSTED_PROXIES=127.0.0.1/32, the address nginx connects from, so
-    # the backend takes that one entry as the client address.
     proxy_set_header Host $host;
     proxy_set_header X-Real-IP $remote_addr;
     proxy_set_header X-Forwarded-For $remote_addr;

go.mod

@@ -17,7 +17,6 @@ require (
 	github.com/slok/go-http-metrics v0.13.0
 	github.com/spf13/viper v1.21.0
 	go.uber.org/fx v1.24.0
-	golang.org/x/sys v0.47.0
 )
 
 require (
@@ -42,6 +41,7 @@ require (
 	go.uber.org/multierr v1.10.0 // indirect
 	go.uber.org/zap v1.26.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/sys v0.47.0 // indirect
 	golang.org/x/text v0.40.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 )

internal/cli/cli.go

@@ -1,143 +0,0 @@
-// Package cli runs netwatch-server from its command line: the
-// check-cidr and prepare-data-dir subcommands, which bin/entrypoint.sh
-// runs before it starts the server, and, given no arguments, the
-// server, with the fx wiring.
-package cli
-
-import (
-	"fmt"
-	"io"
-	"os/user"
-
-	"sneak.berlin/go/netwatch/internal/config"
-	"sneak.berlin/go/netwatch/internal/globals"
-	"sneak.berlin/go/netwatch/internal/handlers"
-	"sneak.berlin/go/netwatch/internal/healthcheck"
-	"sneak.berlin/go/netwatch/internal/logger"
-	"sneak.berlin/go/netwatch/internal/middleware"
-	"sneak.berlin/go/netwatch/internal/reportbuf"
-	"sneak.berlin/go/netwatch/internal/server"
-
-	"go.uber.org/fx"
-	"go.uber.org/fx/fxevent"
-)
-
-// usageExitCode is what Main returns for a command line it does not
-// understand, the usual exit code for a usage error.
-const usageExitCode = 2
-
-// Main runs netwatch-server with args, its command line after the
-// program's name, and returns the exit code. With no args, Main runs
-// the server by calling serve with appname and version, the name and
-// version the server logs and reports. With "check-cidr CIDR" or
-// "prepare-data-dir DATA_DIR" it runs that subcommand, which writes its
-// errors to stderr. Any other args get a one-line usage message on
-// stderr and exit code 2. main passes os.Stderr and RunServer; the
-// tests pass a buffer and a function of their own, so that no test
-// starts the server. When serve is RunServer and the server fails to
-// start, to listen or to stop, fx's Run exits the process with status 1
-// and Main never returns.
-func Main(
-	stderr io.Writer,
-	appname, version string,
-	args []string,
-	serve func(appname, version string),
-) int {
-	// "netwatch-server check-cidr CIDR" exits 1, with the error, if
-	// this server would refuse CIDR in its TRUSTED_PROXIES.
-	// bin/entrypoint.sh runs it on each entry it gives nginx.
-	if len(args) == 2 && args[0] == "check-cidr" {
-		return checkCIDR(stderr, args[1])
-	}
-
-	// "netwatch-server prepare-data-dir DATA_DIR" gets DATA_DIR ready
-	// for the netwatch user, or exits 1 with the error; see
-	// reportbuf.PrepareDataDir. bin/entrypoint.sh runs it as root
-	// before it starts this server as that user.
-	if len(args) == 2 && args[0] == "prepare-data-dir" {
-		return prepareDataDir(stderr, "/data", args[1], "netwatch")
-	}
-
-	// Any other command line is refused, so that a mistyped one does
-	// not start the server.
-	if len(args) > 0 {
-		_, _ = fmt.Fprintln(stderr,
-			"usage: netwatch-server [check-cidr CIDR | prepare-data-dir DATA_DIR]")
-
-		return usageExitCode
-	}
-
-	serve(appname, version)
-
-	return 0
-}
-
-// checkCIDR returns 0 if the server would take cidr in its
-// TRUSTED_PROXIES, and otherwise writes the error to stderr and
-// returns 1.
-func checkCIDR(stderr io.Writer, cidr string) int {
-	_, err := middleware.ParseTrustedProxies([]string{cidr})
-	if err != nil {
-		_, _ = fmt.Fprintln(stderr, err)
-
-		return 1
-	}
-
-	return 0
-}
-
-// prepareDataDir gets dataDir ready for the user named username with
-// reportbuf.PrepareDataDir, volume being where the data volume is
-// mounted, and returns 0. Otherwise it writes the error to stderr and
-// returns 1.
-func prepareDataDir(stderr io.Writer, volume, dataDir, username string) int {
-	owner, err := user.Lookup(username)
-	if err != nil {
-		_, _ = fmt.Fprintln(stderr, err)
-
-		return 1
-	}
-
-	err = reportbuf.PrepareDataDir(volume, dataDir, owner)
-	if err != nil {
-		_, _ = fmt.Fprintf(stderr, "DATA_DIR '%s': %v\n", dataDir, err)
-
-		return 1
-	}
-
-	return 0
-}
-
-// RunServer runs the server until it is told to stop, with appname and
-// version as the name and version it logs and reports. If the server
-// fails to start, to listen or to stop, fx's Run exits the process
-// with status 1 itself.
-func RunServer(appname, version string) {
-	globals.Appname = appname
-	globals.Version = version
-
-	fx.New(
-		// fx logs each step of starting and stopping through the
-		// server's own logger, so off a terminal those lines are
-		// JSON like every other line.
-		fx.WithLogger(func(log *logger.Logger) fxevent.Logger {
-			return &fxevent.SlogLogger{Logger: log.Get()}
-		}),
-		fx.Provide(
-			config.New,
-			globals.New,
-			handlers.New,
-			healthcheck.New,
-			logger.New,
-			middleware.New,
-			reportbuf.New,
-			server.New,
-		),
-		fx.Invoke(
-			// First, so the name and version are logged even when
-			// a setting stops the start.
-			func(log *logger.Logger) { log.Identify() },
-			func(*server.Server) {},
-		),
-	).Run()
-}

internal/cli/cli_test.go

@@ -1,219 +0,0 @@
-package cli_test
-
-import (
-	"bytes"
-	"os"
-	"os/user"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"testing"
-
-	"sneak.berlin/go/netwatch/internal/cli"
-	"sneak.berlin/go/netwatch/internal/reportbuf"
-)
-
-// TestMainRunsCheckCIDR: Main given check-cidr returns 0, writing
-// nothing, for a CIDR the server takes in its TRUSTED_PROXIES, and 1,
-// with an error naming TRUSTED_PROXIES and the CIDR, for one it
-// refuses, and does not start the server.
-func TestMainRunsCheckCIDR(t *testing.T) {
-	t.Parallel()
-
-	var stderr bytes.Buffer
-
-	code := cli.Main(&stderr, "netwatch", "test",
-		[]string{"check-cidr", "10.0.0.0/8"}, failIfServerStarts(t))
-	if code != 0 || stderr.Len() != 0 {
-		t.Errorf("check-cidr 10.0.0.0/8: exit %d, stderr %q; want exit 0 and no output",
-			code, stderr.String())
-	}
-
-	stderr.Reset()
-
-	code = cli.Main(&stderr, "netwatch", "test",
-		[]string{"check-cidr", "1.2.3/32"}, failIfServerStarts(t))
-
-	want := `TRUSTED_PROXIES "1.2.3/32": `
-	if code != 1 || !strings.HasPrefix(stderr.String(), want) {
-		t.Errorf("check-cidr 1.2.3/32: exit %d, stderr %q; want exit 1 and %q...",
-			code, stderr.String(), want)
-	}
-}
-
-// TestMainRunsPrepareDataDir: Main given prepare-data-dir runs the
-// prepare-data-dir subcommand for the netwatch user, and does not start
-// the server. The test image has no netwatch user, so that subcommand
-// exits 1 with the error from looking the user up;
-// TestPrepareDataDirRefusesPathOutsideVolume checks the path.
-func TestMainRunsPrepareDataDir(t *testing.T) {
-	t.Parallel()
-
-	var stderr bytes.Buffer
-
-	code := cli.Main(&stderr, "netwatch", "test",
-		[]string{"prepare-data-dir", "/etc"}, failIfServerStarts(t))
-
-	want := user.UnknownUserError("netwatch").Error() + "\n"
-	if code != 1 || stderr.String() != want {
-		t.Errorf("prepare-data-dir /etc: exit %d, stderr %q; want exit 1 and %q",
-			code, stderr.String(), want)
-	}
-}
-
-// TestMainRunsServerWithNoArguments: Main given no arguments starts the
-// server with the name and version it was given, writes nothing and
-// returns 0.
-func TestMainRunsServerWithNoArguments(t *testing.T) {
-	t.Parallel()
-
-	var (
-		stderr                 bytes.Buffer
-		gotAppname, gotVersion string
-	)
-
-	code := cli.Main(&stderr, "netwatch", "test", []string{},
-		func(appname, version string) {
-			gotAppname, gotVersion = appname, version
-		})
-	if code != 0 || stderr.Len() != 0 {
-		t.Errorf("exit %d, stderr %q; want exit 0 and no output",
-			code, stderr.String())
-	}
-
-	if gotAppname != "netwatch" || gotVersion != "test" {
-		t.Errorf("server started with %q %q; want %q %q",
-			gotAppname, gotVersion, "netwatch", "test")
-	}
-}
-
-// TestMainRefusesOtherCommandLines: Main given a subcommand with too
-// few or too many values, or a misspelt subcommand, writes the usage
-// message to stderr, returns 2 and does not start the server.
-func TestMainRefusesOtherCommandLines(t *testing.T) {
-	t.Parallel()
-
-	want := "usage: netwatch-server " +
-		"[check-cidr CIDR | prepare-data-dir DATA_DIR]\n"
-
-	for _, commandLine := range []string{
-		"netwatch-server check-cidr",
-		"netwatch-server check-cidr 192.0.2.0/24 198.51.100.0/24",
-		"netwatch-server prepare-data-dir",
-		"netwatch-server prepare-data-dir /data/reports /data/other",
-		"netwatch-server check-cdir 192.0.2.0/24",
-	} {
-		var stderr bytes.Buffer
-
-		// Main takes the command line after the program's name.
-		args := strings.Fields(commandLine)[1:]
-
-		code := cli.Main(&stderr, "netwatch", "test", args, failIfServerStarts(t))
-		if code != 2 || stderr.String() != want {
-			t.Errorf("%q: exit %d, stderr %q; want exit 2 and %q",
-				commandLine, code, stderr.String(), want)
-		}
-	}
-}
-
-// TestCheckCIDRTakesCIDR: check-cidr exits 0, writing nothing, for a
-// CIDR the server takes in its TRUSTED_PROXIES.
-func TestCheckCIDRTakesCIDR(t *testing.T) {
-	t.Parallel()
-
-	for _, cidr := range []string{"10.0.0.0/8", "192.0.2.1/32", "2001:db8::/32"} {
-		var stderr bytes.Buffer
-
-		code := cli.CheckCIDR(&stderr, cidr)
-		if code != 0 || stderr.Len() != 0 {
-			t.Errorf("%q: exit %d, stderr %q; want exit 0 and no output",
-				cidr, code, stderr.String())
-		}
-	}
-}
-
-// TestCheckCIDRRefusesOtherInput: check-cidr exits 1, with an error
-// naming TRUSTED_PROXIES and the input, for anything the server would
-// refuse in its TRUSTED_PROXIES, such as 1.2.3/32, which nginx would
-// look up as a hostname.
-func TestCheckCIDRRefusesOtherInput(t *testing.T) {
-	t.Parallel()
-
-	for _, cidr := range []string{
-		"1.2.3/32", "example.com/32", "10.0.0.0/33", "10.0.0.1", "",
-	} {
-		var stderr bytes.Buffer
-
-		code := cli.CheckCIDR(&stderr, cidr)
-
-		want := "TRUSTED_PROXIES " + strconv.Quote(cidr) + ": "
-		if code != 1 || !strings.HasPrefix(stderr.String(), want) {
-			t.Errorf("%q: exit %d, stderr %q; want exit 1 and %q...",
-				cidr, code, stderr.String(), want)
-		}
-	}
-}
-
-// TestPrepareDataDirTakesPathInVolume: prepare-data-dir exits 0,
-// writing nothing, for a DATA_DIR below the volume, and creates it.
-func TestPrepareDataDirTakesPathInVolume(t *testing.T) {
-	t.Parallel()
-
-	volume := t.TempDir()
-	dataDir := filepath.Join(volume, "reports")
-
-	var stderr bytes.Buffer
-
-	code := cli.PrepareDataDir(&stderr, volume, dataDir, currentUsername(t))
-	if code != 0 || stderr.Len() != 0 {
-		t.Errorf("exit %d, stderr %q; want exit 0 and no output",
-			code, stderr.String())
-	}
-
-	info, err := os.Stat(dataDir)
-	if err != nil || !info.IsDir() {
-		t.Errorf("DATA_DIR not created: %v", err)
-	}
-}
-
-// TestPrepareDataDirRefusesPathOutsideVolume: prepare-data-dir exits
-// 1, with an error naming DATA_DIR and its value, for a DATA_DIR
-// outside the volume.
-func TestPrepareDataDirRefusesPathOutsideVolume(t *testing.T) {
-	t.Parallel()
-
-	volume := t.TempDir()
-
-	var stderr bytes.Buffer
-
-	code := cli.PrepareDataDir(&stderr, volume, "/etc", currentUsername(t))
-
-	want := "DATA_DIR '/etc': " + reportbuf.ErrDataDirOutsideVolume.Error() + "\n"
-	if code != 1 || stderr.String() != want {
-		t.Errorf("exit %d, stderr %q; want exit 1 and %q",
-			code, stderr.String(), want)
-	}
-}
-
-// currentUsername is the name of the user the test runs as, the only
-// owner a test not run as root can give files to.
-func currentUsername(t *testing.T) string {
-	t.Helper()
-
-	current, err := user.Current()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	return current.Username
-}
-
-// failIfServerStarts is what the tests give Main in place of
-// cli.RunServer: it fails the test instead of starting the server.
-func failIfServerStarts(t *testing.T) func(appname, version string) {
-	t.Helper()
-
-	return func(string, string) {
-		t.Error("Main started the server")
-	}
-}

internal/cli/export_test.go

@@ -1,16 +0,0 @@
-package cli
-
-import "io"
-
-// CheckCIDR exposes the check-cidr subcommand to the external tests,
-// which read what it writes to stderr.
-func CheckCIDR(stderr io.Writer, cidr string) int {
-	return checkCIDR(stderr, cidr)
-}
-
-// PrepareDataDir exposes the prepare-data-dir subcommand to the
-// external tests, which give it a volume and a user of their own in
-// place of /data and netwatch.
-func PrepareDataDir(stderr io.Writer, volume, dataDir, username string) int {
-	return prepareDataDir(stderr, volume, dataDir, username)
-}

internal/config/config.go

@@ -9,7 +9,6 @@ import (
 	"math"
 	"net/netip"
 	"net/url"
-	"os"
 	"strconv"
 	"strings"
 
@@ -22,11 +21,13 @@ import (
 )
 
 // defaultTrustedProxies lists the networks whose forwarded
-// headers are honoured when TRUSTED_PROXIES is unset: the
+// headers are honoured by default: IPv4 and IPv6 loopback,
-// RFC 1918 ranges. The container image does not use it:
+// for a reverse proxy on the same host, and the RFC1918
+// ranges. The container image does not use it:
 // bin/entrypoint.sh gives the server 127.0.0.1/32, since
 // nginx is its only client there.
-const defaultTrustedProxies = "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"
+const defaultTrustedProxies = "127.0.0.1/32,::1/128," +
+	"10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"
 
 // Default limits on stored reports; README.md gives the reasons for
 // these values.
@@ -41,6 +42,7 @@ var (
 		"must be an origin, scheme://host with an optional port",
 	)
 	errNotPort = errors.New("must be a port number, 1 to 65535")
+	errNotBool = errors.New("must be true or false")
 	errNotIP   = errors.New("must be an IP address, or empty")
 
 	errMetricsCredentials = errors.New(
@@ -100,7 +102,7 @@ func New(
 	viper.SetDefault("CORS_ALLOWED_ORIGINS", "")
 	viper.SetDefault("DATA_DIR", "./data/reports")
 	viper.SetDefault("DATA_DIR_MAX_BYTES", defaultDataDirMaxBytes)
-	viper.SetDefault("DEBUG", "")
+	viper.SetDefault("DEBUG", "false")
 	// An empty BIND_ADDRESS listens on every interface.
 	viper.SetDefault("BIND_ADDRESS", "")
 	viper.SetDefault("PORT", "8080")
@@ -119,24 +121,18 @@ func New(
 		}
 	}
 
-	// Read with strconv: viper's GetInt would read a value it cannot
+	// Read with strconv: viper's GetInt and GetBool would read a value
-	// parse as 0 instead of failing.
+	// they cannot parse as 0 or false instead of failing.
 	port, err := strconv.Atoi(viper.GetString("PORT"))
 	if err != nil || port < 1 || port > math.MaxUint16 {
 		return nil, fmt.Errorf("PORT %q: %w",
 			viper.GetString("PORT"), errNotPort)
 	}
 
-	// Any non-empty value turns debug logging on, "false" and "0"
+	debug, err := strconv.ParseBool(viper.GetString("DEBUG"))
-	// included, as the code style guide says.
+	if err != nil {
-	debug := viper.GetString("DEBUG") != ""
+		return nil, fmt.Errorf("DEBUG %q: %w",
-
+			viper.GetString("DEBUG"), errNotBool)
-	// An empty TRUSTED_PROXIES trusts no proxy, but viper reads an
-	// empty environment variable as unset and would give the default,
-	// so the environment is read first.
-	trustedProxies, set := os.LookupEnv("TRUSTED_PROXIES")
-	if !set {
-		trustedProxies = viper.GetString("TRUSTED_PROXIES")
 	}
 
 	s := &Config{
@@ -150,7 +146,7 @@ func New(
 		Port:               port,
 		ReportsPerMinute:   viper.GetInt("REPORTS_PER_MINUTE"),
 		SentryDSN:          viper.GetString("SENTRY_DSN"),
-		TrustedProxies:     splitList(trustedProxies),
+		TrustedProxies:     splitList(viper.GetString("TRUSTED_PROXIES")),
 		log:                log,
 		params:             &params,
 	}
@@ -169,8 +165,8 @@ func New(
 }
 
 // check fails with an error naming the first setting here whose value
-// the server cannot use. New checks PORT as it reads it, and the
+// the server cannot use. New checks PORT and DEBUG as it reads them,
-// middleware checks TRUSTED_PROXIES as it parses it.
+// and the middleware checks TRUSTED_PROXIES as it parses it.
 func (s *Config) check() error {
 	// viper reads a value that is not a number as 0, so this also
 	// catches a mistyped setting.

internal/config/config_test.go

@@ -1,8 +1,6 @@
 package config_test
 
 import (
-	"os"
-	"slices"
 	"strings"
 	"testing"
 
@@ -13,8 +11,8 @@ import (
 	"go.uber.org/fx"
 )
 
-// requireConfigError builds the config as cli.RunServer does and fails
+// requireConfigError builds the config as main does and fails the
-// the test unless that fails with an error naming setting. It uses
+// test unless that fails with an error naming setting. It uses
 // fx.New, because fxtest.New fails the test itself on an error.
 func requireConfigError(t *testing.T, setting string) {
 	t.Helper()
@@ -31,62 +29,6 @@ func requireConfigError(t *testing.T, setting string) {
 	}
 }
 
-// requireTrustedProxies builds the config as cli.RunServer does and
-// fails the test unless its TrustedProxies are want.
-func requireTrustedProxies(t *testing.T, want []string) {
-	t.Helper()
-
-	var cfg *config.Config
-
-	app := fx.New(
-		fx.NopLogger,
-		fx.Provide(globals.New, logger.New, config.New),
-		fx.Populate(&cfg),
-	)
-
-	err := app.Err()
-	if err != nil {
-		t.Fatalf("config error = %v", err)
-	}
-
-	if !slices.Equal(cfg.TrustedProxies, want) {
-		t.Fatalf("TrustedProxies = %q, want %q", cfg.TrustedProxies, want)
-	}
-}
-
-// TestTrustedProxiesUnsetTrustsRFC1918: unset, the server trusts the
-// RFC 1918 ranges and nothing else, loopback included.
-func TestTrustedProxiesUnsetTrustsRFC1918(t *testing.T) {
-	// t.Setenv first, so the variable is put back as it was after the
-	// test.
-	t.Setenv("TRUSTED_PROXIES", "")
-
-	err := os.Unsetenv("TRUSTED_PROXIES")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	requireTrustedProxies(t,
-		[]string{"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"})
-}
-
-// TestTrustedProxiesEmptyTrustsNothing: set and empty, the server
-// trusts no proxy. viper alone would read the empty variable as unset
-// and give the default.
-func TestTrustedProxiesEmptyTrustsNothing(t *testing.T) {
-	t.Setenv("TRUSTED_PROXIES", "")
-
-	requireTrustedProxies(t, []string{})
-}
-
-// TestTrustedProxiesListReplacesDefault: a list is used as given, with
-// none of the default ranges added.
-func TestTrustedProxiesListReplacesDefault(t *testing.T) {
-	t.Setenv("TRUSTED_PROXIES", "172.17.0.1/32, 2001:db8::/32")
-
-	requireTrustedProxies(t, []string{"172.17.0.1/32", "2001:db8::/32"})
-}
-
 // TestSettingsLoadAsGiven: valid values pass the checks and are used
 // as given. bin/entrypoint.sh starts the server with these
 // BIND_ADDRESS and PORT values.
@@ -127,52 +69,12 @@ func TestPortMustBeAPortNumber(t *testing.T) {
 	}
 }
 
-// TestDebugIsOnForAnyNonEmptyValue: unset or empty, debug logging is
+// TestDebugMustBeTrueOrFalse: viper reads any other value, such as
-// off; any other value turns it on, "false" and "0" included, and none
+// "yes", as false.
-// stops the start.
+func TestDebugMustBeTrueOrFalse(t *testing.T) {
-func TestDebugIsOnForAnyNonEmptyValue(t *testing.T) {
+	t.Setenv("DEBUG", "yes")
-	for _, tc := range []struct {
-		name  string
-		value string
-		unset bool
-		want  bool
-	}{
-		{name: "unset", unset: true, want: false},
-		{name: "empty", value: "", want: false},
-		{name: "false", value: "false", want: true},
-		{name: "0", value: "0", want: true},
-		{name: "yes", value: "yes", want: true},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			// t.Setenv first, so the variable is put back as it was
-			// after the test.
-			t.Setenv("DEBUG", tc.value)
 
-			if tc.unset {
+	requireConfigError(t, "DEBUG")
-				err := os.Unsetenv("DEBUG")
-				if err != nil {
-					t.Fatal(err)
-				}
-			}
-
-			var cfg *config.Config
-
-			app := fx.New(
-				fx.NopLogger,
-				fx.Provide(globals.New, logger.New, config.New),
-				fx.Populate(&cfg),
-			)
-
-			err := app.Err()
-			if err != nil {
-				t.Fatalf("config error = %v", err)
-			}
-
-			if cfg.Debug != tc.want {
-				t.Fatalf("Debug = %t, want %t", cfg.Debug, tc.want)
-			}
-		})
-	}
 }
 
 // TestBindAddressMustBeAnIPAddress: a host name would be looked up

internal/globals/globals.go

@@ -4,7 +4,7 @@ package globals
 
 import "go.uber.org/fx"
 
-//nolint:gochecknoglobals // set by cli.RunServer before fx starts
+//nolint:gochecknoglobals // set from main before fx starts
 var (
 	// Appname is the application name.
 	Appname string

internal/handlers/healthcheck.go

@@ -3,17 +3,9 @@ package handlers
 import "net/http"
 
 // HandleHealthCheck returns a handler for the health check
-// endpoint. It answers 200 while the status is "ok" and 503 otherwise,
+// endpoint.
-// so that the image's HEALTHCHECK fails.
 func (s *Handlers) HandleHealthCheck() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		resp := s.hc.Healthcheck()
+		s.respondJSON(w, r, s.hc.Healthcheck(), http.StatusOK)
-
-		code := http.StatusOK
-		if resp.Status != "ok" {
-			code = http.StatusServiceUnavailable
-		}
-
-		s.respondJSON(w, r, resp, code)
 	}
 }

internal/handlers/healthcheck_test.go

@@ -9,19 +9,17 @@ import (
 	"testing"
 	"time"
 
-	"sneak.berlin/go/netwatch/internal/config"
 	"sneak.berlin/go/netwatch/internal/globals"
 	"sneak.berlin/go/netwatch/internal/handlers"
 	"sneak.berlin/go/netwatch/internal/healthcheck"
 	"sneak.berlin/go/netwatch/internal/logger"
-	"sneak.berlin/go/netwatch/internal/reportbuf"
 
 	"go.uber.org/fx/fxtest"
 )
 
 // newStartedHandlers builds Handlers with a real health check for the
-// server named in g, and a report buffer in a temporary directory, and
+// server named in g, and starts them, which records the time the
-// starts them, which records the time the uptime counts from.
+// uptime counts from.
 func newStartedHandlers(t *testing.T, g *globals.Globals) *handlers.Handlers {
 	t.Helper()
 
@@ -32,23 +30,14 @@ func newStartedHandlers(t *testing.T, g *globals.Globals) *handlers.Handlers {
 		t.Fatalf("logger: %v", err)
 	}
 
-	buf, err := reportbuf.New(lc, reportbuf.Params{
-		Config: &config.Config{DataDir: t.TempDir(), DataDirMaxBytes: 1 << 20},
-		Logger: log,
-	})
-	if err != nil {
-		t.Fatalf("report buffer: %v", err)
-	}
-
 	hc, err := healthcheck.New(lc,
-		healthcheck.Params{Buffer: buf, Globals: g, Logger: log})
+		healthcheck.Params{Globals: g, Logger: log})
 	if err != nil {
 		t.Fatalf("health check: %v", err)
 	}
 
-	h, err := handlers.New(lc, handlers.Params{
+	h, err := handlers.New(lc,
-		Buffer: buf, Globals: g, Healthcheck: hc, Logger: log,
+		handlers.Params{Globals: g, Healthcheck: hc, Logger: log})
-	})
 	if err != nil {
 		t.Fatalf("handlers: %v", err)
 	}
@@ -59,12 +48,10 @@ func newStartedHandlers(t *testing.T, g *globals.Globals) *handlers.Handlers {
 	return h
 }
 
-// TestHandleHealthCheck checks the health check's answer at start, when
+// TestHandleHealthCheck checks the health check's answer: 200, a JSON
-// no write of a report file has failed: 200, a JSON content type, and a
+// content type, and a JSON object with exactly the fields of
-// JSON object with exactly the fields of healthcheck.HealthcheckResponse,
+// healthcheck.HealthcheckResponse, carrying this server's name and
-// carrying "status":"ok", this server's name and version and an uptime
+// version and an uptime counted from its start.
-// counted from its start. The answer while writes fail is checked in
-// internal/reportbuf, whose tests can make a write fail.
 func TestHandleHealthCheck(t *testing.T) {
 	t.Parallel()
 

internal/healthcheck/healthcheck.go

@@ -10,7 +10,6 @@ import (
 	"sneak.berlin/go/netwatch/internal/config"
 	"sneak.berlin/go/netwatch/internal/globals"
 	"sneak.berlin/go/netwatch/internal/logger"
-	"sneak.berlin/go/netwatch/internal/reportbuf"
 
 	"go.uber.org/fx"
 )
@@ -19,7 +18,6 @@ import (
 type Params struct {
 	fx.In
 
-	Buffer  *reportbuf.Buffer
 	Config  *config.Config
 	Globals *globals.Globals
 	Logger  *logger.Logger
@@ -70,18 +68,12 @@ func New(
 	return s, nil
 }
 
-// Healthcheck returns the current health status of the application:
+// Healthcheck returns the current health status of the application.
-// "ok", or "error" while report files cannot be written.
 func (s *Healthcheck) Healthcheck() *HealthcheckResponse {
-	status := "ok"
-	if s.params.Buffer.LastWriteFailed() {
-		status = "error"
-	}
-
 	return &HealthcheckResponse{
 		Appname:       s.params.Globals.Appname,
 		Now:           time.Now().UTC().Format(time.RFC3339Nano),
-		Status:        status,
+		Status:        "ok",
 		UptimeHuman:   s.uptime().String(),
 		UptimeSeconds: int64(s.uptime().Seconds()),
 		Version:       s.params.Globals.Version,

internal/middleware/middleware.go

@@ -11,7 +11,6 @@ import (
 	"net/http"
 	"net/netip"
 	"runtime/debug"
-	"slices"
 	"strings"
 	"time"
 
@@ -134,17 +133,6 @@ func ipFromHostPort(hostPort string) string {
 // X-Real-IP are honoured only when the direct peer is a
 // trusted proxy; otherwise the direct peer is returned so a
 // spoofed header cannot forge the logged address.
-//
-// Each proxy appends to X-Forwarded-For the address it took the
-// request from, so the entries on the right are written by the
-// trusted proxies and those further left by the client. The
-// client's address is therefore the right-most entry that is not
-// a trusted proxy. An entry written as an address with a port is
-// read as that address, both for the trust check and as the
-// result. When every entry is a trusted proxy, or the walk from
-// the right meets an entry that is not an address at all (such as
-// "unknown"), the peer is used. X-Real-IP is read only when there
-// is no X-Forwarded-For entry at all.
 func clientIP(
 	remoteAddr string,
 	header http.Header,
@@ -156,49 +144,28 @@ func clientIP(
 		return peer
 	}
 
-	forwarded := forwardedFor(header)
+	if xff := firstForwardedFor(header.Get("X-Forwarded-For")); xff != "" {
-
+		return xff
-	if len(forwarded) == 0 {
-		if xr := strings.TrimSpace(header.Get("X-Real-IP")); validIP(xr) {
-			return xr
-		}
-
-		return peer
 	}
 
-	for _, entry := range slices.Backward(forwarded) {
+	if xr := strings.TrimSpace(header.Get("X-Real-IP")); validIP(xr) {
-		if !validIP(entry) {
+		return xr
-			return peer
-		}
-
-		if !addrInAny(entry, trusted) {
-			return entry
-		}
 	}
 
 	return peer
 }
 
-// forwardedFor returns the entries of X-Forwarded-For in order,
+// firstForwardedFor returns the left-most valid address in an
-// leaving out blank ones. A proxy may add its entry as a header
+// X-Forwarded-For list (the original client), or "" if none.
-// line of its own rather than append it to the line the client
+func firstForwardedFor(value string) string {
-// sent, so every line is read, not only the first. Some proxies
-// write an entry as an address with a port, such as
-// 198.51.100.7:5000 or [2001:db8::1]:443; the port is removed so
-// that the entry is read as its address.
-func forwardedFor(header http.Header) []string {
-	value := strings.Join(header.Values("X-Forwarded-For"), ",")
-
-	var entries []string
-
 	for part := range strings.SplitSeq(value, ",") {
-		entry := strings.TrimSpace(part)
+		candidate := strings.TrimSpace(part)
-		if entry != "" {
+		if validIP(candidate) {
-			entries = append(entries, ipFromHostPort(entry))
+			return candidate
 		}
 	}
 
-	return entries
+	return ""
 }
 
 func validIP(s string) bool {

internal/middleware/middleware_test.go

@@ -25,16 +25,10 @@ import (
 const (
 	// loopbackPeer is a remote address inside the trusted-proxy allowlist.
 	loopbackPeer = "127.0.0.1:5000"
-	// loopbackIP is the address of loopbackPeer, which ClientIP returns
-	// when it uses the peer.
-	loopbackIP = "127.0.0.1"
 	// forwardedIP is the client address presented via X-Forwarded-For.
 	forwardedIP = "203.0.113.7"
 	// realIP is the client address presented via X-Real-IP.
 	realIP = "203.0.113.9"
-	// appendedIP is the X-Forwarded-For entry a trusted proxy appended
-	// after the entries the client wrote.
-	appendedIP = "198.51.100.7"
 )
 
 func mustPrefixes(t *testing.T, cidrs ...string) []netip.Prefix {
@@ -91,35 +85,10 @@ func clientIPCases() []clientIPCase {
 			want:       forwardedIP,
 		},
 		{
-			name:       "trusted proxy uses right-most of chain",
+			name:       "trusted proxy uses left-most of chain",
-			remoteAddr: loopbackPeer,
+			remoteAddr: "10.1.2.3:5000",
-			xff:        "203.0.113.9, " + appendedIP,
+			xff:        forwardedIP + ", 10.1.2.3",
-			want:       appendedIP,
+			want:       forwardedIP,
-		},
-		{
-			name:       "trusted proxy entries are skipped from the right",
-			remoteAddr: loopbackPeer,
-			xff:        "203.0.113.9, 10.0.0.5",
-			want:       "203.0.113.9",
-		},
-		{
-			name:       "chain of only trusted proxies uses peer",
-			remoteAddr: loopbackPeer,
-			xff:        "10.0.0.5, 10.1.2.3",
-			want:       loopbackIP,
-		},
-		{
-			name:       "entry that is not an address uses peer",
-			remoteAddr: loopbackPeer,
-			xff:        "203.0.113.9, unknown",
-			want:       loopbackIP,
-		},
-		{
-			name:       "x-real-ip ignored when forwarded-for has entries",
-			remoteAddr: loopbackPeer,
-			xff:        "10.0.0.5",
-			xRealIP:    realIP,
-			want:       loopbackIP,
 		},
 		{
 			name:       "trusted proxy falls back to x-real-ip",
@@ -148,7 +117,7 @@ func clientIPCases() []clientIPCase {
 			name:       "trusted proxy with garbage header uses peer",
 			remoteAddr: loopbackPeer,
 			xff:        "not-an-ip",
-			want:       loopbackIP,
+			want:       "127.0.0.1",
 		},
 	}
 }
@@ -179,47 +148,6 @@ func TestClientIP(t *testing.T) {
 	}
 }
 
-// TestClientIPReadsEveryForwardedForLine checks that an entry a proxy
-// adds as an X-Forwarded-For line of its own is read, and the line the
-// client sent before it is not taken.
-func TestClientIPReadsEveryForwardedForLine(t *testing.T) {
-	t.Parallel()
-
-	header := http.Header{}
-	header.Add("X-Forwarded-For", "203.0.113.9")
-	header.Add("X-Forwarded-For", appendedIP)
-
-	got := middleware.ClientIP(loopbackPeer, header,
-		mustPrefixes(t, "127.0.0.1/32"))
-	if got != appendedIP {
-		t.Errorf("ClientIP() = %q, want %q", got, appendedIP)
-	}
-}
-
-// TestClientIPReadsAddressWithPort checks that an X-Forwarded-For entry
-// written as an address with a port is read as that address, both for
-// the trust check and as the result.
-func TestClientIPReadsAddressWithPort(t *testing.T) {
-	t.Parallel()
-
-	trusted := mustPrefixes(t, "127.0.0.1/32", "10.0.0.0/8")
-
-	for xff, want := range map[string]string{
-		"203.0.113.9, " + appendedIP + ":5000": appendedIP,
-		"203.0.113.9, [2001:db8::1]:443":       "2001:db8::1",
-		"203.0.113.9, 10.0.0.5:5000":           "203.0.113.9",
-	} {
-		header := http.Header{}
-		header.Set("X-Forwarded-For", xff)
-
-		got := middleware.ClientIP(loopbackPeer, header, trusted)
-		if got != want {
-			t.Errorf("X-Forwarded-For %q: ClientIP() = %q, want %q",
-				xff, got, want)
-		}
-	}
-}
-
 func TestSecurityHeaders(t *testing.T) {
 	t.Parallel()
 

internal/reportbuf/datadir.go

@@ -18,15 +18,9 @@ var ErrDataDirOutsideVolume = errors.New(
 // PrepareDataDir gets dir, the server's DATA_DIR, ready for owner, the
 // user the server runs as, so that a host directory mounted at volume,
 // /data in the image, needs no preparing: it creates dir, gives volume
-// and the directories, regular files and symbolic links in it to
+// and everything in it to owner, and gives volume and dir the mode the
-// owner, and gives volume and dir the mode the server gives a directory
+// server gives a directory it creates. dir must be volume or a path
-// it creates. It leaves a file with a second name (hard link) as it
+// below it, with no '.', '..', empty part or '/' at the end.
-// is, as that name could be outside volume, and logs its path; it
-// leaves a device, named pipe or socket as it is too (see chownFile).
-// dir must be volume or a path below it, with no '.', '..', empty part
-// or '/' at the end. On any system but Linux, the system of the image, it
-// fails at the first file in volume that is not a directory (see
-// chownFile).
 //
 // bin/entrypoint.sh runs this as root, which would follow a symbolic
 // link anywhere, so every step goes through an os.Root opened on
@@ -38,9 +32,10 @@ var ErrDataDirOutsideVolume = errors.New(
 // open, never following a link at the name it creates, and follows a
 // link on the path only as the os.Root allows, so a relative link
 // inside volume can lead it to create directories elsewhere inside
-// volume. The owners and modes are set on files already opened (see
+// volume. Lchown never changes what a link points to, and the modes
-// chownAll and chmodDir), so the most that process can do is make a
+// are set on directories already opened (see chmodDir), so the most
-// step fail or wait, or act on something else inside volume.
+// that process can do is make a step fail or wait, or act on
+// something else inside volume.
 func PrepareDataDir(volume, dir string, owner *user.User) error {
 	// rel is dir as a path from volume; IsLocal is false for one that
 	// leads out of it.
@@ -71,7 +66,7 @@ func PrepareDataDir(volume, dir string, owner *user.User) error {
 		return err
 	}
 
-	err = chownAll(root, ".", uid, gid)
+	err = lchownAll(root, ".", uid, gid)
 	if err != nil {
 		return err
 	}
@@ -84,23 +79,28 @@ func PrepareDataDir(volume, dir string, owner *user.User) error {
 	return chmodDir(root, rel)
 }
 
-// chownAll gives name, a directory inside root, and the directories,
+// lchownAll gives name, a directory inside root, and everything in it
-// regular files and symbolic links in it to uid and gid, but not the
+// to uid and gid. It reads each directory opened through root, not
-// files chownFile leaves. It opens each through root and gives the
+// through root.FS(), which refuses a name that is not valid UTF-8, and
-// open file to them, as chmodDir sets a mode on the open directory.
+// calls Lchown on every entry, which gives a symbolic link itself to
-// Root.Lchown would not hold: it acts on whatever is at the name by
+// them, not what it points to. It goes into an entry only when the
-// then, and a hard link swapped in there shares its owner with a file
+// read found a directory there, so it follows no link it finds; one
-// that could be outside root. A symbolic link is given to them itself,
+// swapped in for that directory afterwards is followed only as the
-// never what it points to, because in a directory that anyone can
+// os.Root allows.
-// write to and that has the sticky bit set, as /tmp has, the kernel
+func lchownAll(root *os.Root, name string, uid, gid int) error {
-// follows a link only for the link's owner or when the link and the
+	err := root.Lchown(name, uid, gid)
-// directory have the same owner. chownAll goes into an entry only when
+	if err != nil {
-// the read found a directory there, so it follows no link it finds;
+		return err
-// one swapped in afterwards for a directory is followed only as the
+	}
-// os.Root allows, and one swapped in for any other file is not
+
-// followed at all (see chownFile).
+	dir, err := root.Open(name)
-func chownAll(root *os.Root, name string, uid, gid int) error {
+	if err != nil {
-	entries, err := chownDir(root, name, uid, gid)
+		return err
+	}
+
+	entries, err := dir.ReadDir(-1)
+	_ = dir.Close()
+
 	if err != nil {
 		return err
 	}
@@ -108,9 +108,9 @@ func chownAll(root *os.Root, name string, uid, gid int) error {
 	for _, entry := range entries {
 		entryName := filepath.Join(name, entry.Name())
 		if entry.IsDir() {
-			err = chownAll(root, entryName, uid, gid)
+			err = lchownAll(root, entryName, uid, gid)
 		} else {
-			err = chownFile(root, entryName, uid, gid)
+			err = root.Lchown(entryName, uid, gid)
 		}
 
 		if err != nil {
@@ -121,36 +121,6 @@ func chownAll(root *os.Root, name string, uid, gid int) error {
 	return nil
 }
 
-// chownDir gives name, a directory inside root, to uid and gid, and
-// returns what it holds. Like chmodDir, it opens name through root and
-// refuses anything but a directory, which has no second name (hard
-// link). It reads the open directory, not root.FS(), which refuses a
-// name that is not valid UTF-8.
-func chownDir(root *os.Root, name string, uid, gid int) ([]fs.DirEntry, error) {
-	dir, err := root.Open(name)
-	if err != nil {
-		return nil, err
-	}
-
-	defer func() { _ = dir.Close() }()
-
-	info, err := dir.Stat()
-	if err != nil {
-		return nil, err
-	}
-
-	if !info.IsDir() {
-		return nil, &fs.PathError{Op: "chown", Path: name, Err: syscall.ENOTDIR}
-	}
-
-	err = dir.Chown(uid, gid)
-	if err != nil {
-		return nil, err
-	}
-
-	return dir.ReadDir(-1)
-}
-
 // chmodDir gives name, a directory inside root, the mode the server
 // gives a directory it creates. Root.Chmod would not hold: on Linux it
 // checks that name is not a symbolic link, then sets the mode by name,

internal/reportbuf/datadir_linux.go

@@ -1,65 +0,0 @@
-//go:build linux
-
-package reportbuf
-
-import (
-	"io/fs"
-	"log/slog"
-	"os"
-	"syscall"
-
-	"golang.org/x/sys/unix"
-)
-
-// chownFile gives name, a file inside root that is not a directory, to
-// uid and gid if it is a regular file or symbolic link with one name.
-// It leaves, and logs, a file of any kind with a second name (hard
-// link): all the names of a file share its owner, and the other could
-// be outside root. It leaves any other file with one name, such as a
-// device, named pipe or socket: the server needs to own none of them.
-// It opens name through root with O_PATH, which reads nothing from the
-// file, so opening a device or named pipe neither waits nor acts on
-// it; os.Root adds O_NOFOLLOW, and the two together open a symbolic
-// link itself, never what it points to. It reads the kind of file and
-// its number of names from the open file and gives that file to them,
-// so a hard link swapped in at name is caught too.
-//
-// This file is built only on Linux: prepare-data-dir runs only in the
-// Linux image, and macOS, where the backend is also built for
-// development, has neither O_PATH nor AT_EMPTY_PATH. On any other
-// system chownFile returns an error (see datadir_other.go).
-func chownFile(root *os.Root, name string, uid, gid int) error {
-	file, err := root.OpenFile(name, unix.O_PATH, 0)
-	if err != nil {
-		return err
-	}
-
-	defer func() { _ = file.Close() }()
-
-	info, err := file.Stat()
-	if err != nil {
-		return err
-	}
-
-	stat, ok := info.Sys().(*syscall.Stat_t)
-	if !ok || stat.Nlink > 1 {
-		slog.Warn("owner not changed: file has a second name (hard link)",
-			"path", file.Name())
-
-		return nil
-	}
-
-	if !info.Mode().IsRegular() && info.Mode().Type() != fs.ModeSymlink {
-		return nil
-	}
-
-	// File.Chown would fail: fchown refuses a file opened with O_PATH.
-	// Fchownat with an empty name and AT_EMPTY_PATH acts on the open
-	// file instead.
-	err = unix.Fchownat(int(file.Fd()), "", uid, gid, unix.AT_EMPTY_PATH)
-	if err != nil {
-		return &fs.PathError{Op: "chown", Path: file.Name(), Err: err}
-	}
-
-	return nil
-}

internal/reportbuf/datadir_other.go

@@ -1,21 +0,0 @@
-//go:build !linux
-
-package reportbuf
-
-import (
-	"errors"
-	"io/fs"
-	"os"
-)
-
-// chownFile returns an error on every system but Linux. Opening a file
-// that is not a directory without reading it or following it, and
-// giving it to a user on the open file, never by name, is built only
-// for Linux (see datadir_linux.go): prepare-data-dir runs only in the
-// Linux image, and macOS, where the backend is also built for
-// development, has neither O_PATH nor AT_EMPTY_PATH. This file lets
-// the package build elsewhere, such as on macOS, where a developer
-// runs make build and make run.
-func chownFile(_ *os.Root, name string, _, _ int) error {
-	return &fs.PathError{Op: "chown", Path: name, Err: errors.ErrUnsupported}
-}

internal/reportbuf/datadir_test.go

@@ -254,13 +254,10 @@ func TestPrepareDataDirTakesDirectoryNamedInLatin1(t *testing.T) {
 	requireOwner(t, filepath.Join(latin1, "f"), uint32(uid), uint32(gid))
 }
 
-// TestPrepareDataDirGivesVolumeToOwner gives the directories, regular
+// TestPrepareDataDirGivesVolumeToOwner gives everything in the volume
-// files and symbolic links in the volume to a uid and gid that own
+// to a uid and gid that own nothing, which only root can do. A
-// nothing, which only root can do. A symbolic link in the volume to a
+// symbolic link in the volume to a directory outside it is given to
-// directory outside it is given to them itself; what it points to is
+// them itself; what it points to is left as it was.
-// left as it was. A hard link to a file outside the volume, one to a
-// symbolic link outside it and one to a named pipe outside it are left
-// as they were, and so is a named pipe in the volume.
 func TestPrepareDataDirGivesVolumeToOwner(t *testing.T) {
 	t.Parallel()
 
@@ -277,16 +274,6 @@ func TestPrepareDataDirGivesVolumeToOwner(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = os.Symlink("f", filepath.Join(outside, "link"))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	err = syscall.Mkfifo(filepath.Join(outside, "fifo"), 0o600)
-	if err != nil {
-		t.Fatal(err)
-	}
-
 	err = os.Mkdir(old, 0o700)
 	if err != nil {
 		t.Fatal(err)
@@ -302,21 +289,6 @@ func TestPrepareDataDirGivesVolumeToOwner(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = syscall.Mkfifo(filepath.Join(old, "fifo"), 0o600)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	// os.Link does not follow a symbolic link: it gives the link itself
-	// a second name.
-	for _, name := range []string{"f", "link", "fifo"} {
-		err = os.Link(filepath.Join(outside, name),
-			filepath.Join(old, "hardlink-to-"+name))
-		if err != nil {
-			t.Fatal(err)
-		}
-	}
-
 	err = reportbuf.PrepareDataDir(volume, filepath.Join(volume, reports),
 		&user.User{Uid: "4242", Gid: "4343"})
 	if err != nil {
@@ -324,16 +296,12 @@ func TestPrepareDataDirGivesVolumeToOwner(t *testing.T) {
 	}
 
 	for _, path := range []string{
-		volume, filepath.Join(volume, reports), old, filepath.Join(old, "f"),
+		volume, filepath.Join(volume, reports), old,
-		filepath.Join(old, "link"),
+		filepath.Join(old, "f"), filepath.Join(old, "link"),
 	} {
 		requireOwner(t, path, 4242, 4343)
 	}
 
-	for _, path := range []string{
+	requireOwner(t, outside, 0, 0)
-		outside, filepath.Join(outside, "f"), filepath.Join(outside, "link"),
+	requireOwner(t, filepath.Join(outside, "f"), 0, 0)
-		filepath.Join(outside, "fifo"), filepath.Join(old, "fifo"),
-	} {
-		requireOwner(t, path, 0, 0)
-	}
 }

internal/reportbuf/reportbuf.go

@@ -1,9 +1,6 @@
 // Package reportbuf accumulates telemetry reports in memory
 // and periodically flushes them to zstd-compressed JSONL files,
-// deleting the oldest files to keep them under a size cap. Before the
+// deleting the oldest files to keep them under a size cap.
-// server starts, PrepareDataDir gets the directory those files are
-// kept in, DATA_DIR, ready for the user the server runs as: it creates
-// it and gives it and the volume it is on to that user.
 package reportbuf
 
 import (
@@ -16,6 +13,7 @@ import (
 	"log/slog"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -72,9 +70,11 @@ type Buffer struct {
 	// except in tests that hold the write open or make it fail.
 	fileCreated func(f *os.File)
 	// files are the report files that may be deleted to make room,
-	// oldest first: those in dataDir at start, in name order, then
+	// in name order, which is oldest first: those in dataDir at
-	// each one this buffer writes, once it is complete. A file still
+	// start, and each one this buffer writes, put in at its place by
-	// being written is not among them. filesBytes is their total size.
+	// name once it is complete, even when an older file's write
+	// completes after a newer one's. A file still being written is
+	// not among them. filesBytes is their total size.
 	files      []reportFile
 	filesBytes int64
 	log        *slog.Logger
@@ -85,12 +85,8 @@ type Buffer struct {
 	now func() time.Time
 	// seq numbers the report files, so that two named in the same
 	// millisecond still get different names.
-	seq      atomic.Int64
+	seq      atomic.Uint64
 	stopOnce sync.Once
-	// thresholdWriteWaiting is set while a write Append started at
-	// flushSizeThreshold waits for writeMu; Append starts no other
-	// while it is set.
-	thresholdWriteWaiting atomic.Bool
 	// usedBytes is what Append checks against maxBytes: the size
 	// of the report files in dataDir, plus the reports waiting to
 	// be written to one at their uncompressed size.
@@ -100,15 +96,6 @@ type Buffer struct {
 	// refuses reports, and the reports of that write wait in buf for
 	// the next flush.
 	writeErr error
-	// writeMu is held across each write of a report file, so writes
-	// never overlap: a failed write puts its reports back in buf before
-	// the next write takes them, which keeps them in the order they
-	// were appended.
-	writeMu sync.Mutex
-	// writers are the goroutines that write report files: flushLoop,
-	// and each one Append starts at flushSizeThreshold. OnStop waits
-	// for them before the final flush.
-	writers sync.WaitGroup
 }
 
 // New creates a Buffer and registers lifecycle hooks to
@@ -133,33 +120,16 @@ func New(
 
 	lc.Append(fx.Hook{
 		OnStart: func(_ context.Context) error {
-			// The errors name DATA_DIR, as config.New's do for the
-			// settings it checks.
 			err := os.MkdirAll(b.dataDir, dirPerms)
 			if err != nil {
-				return fmt.Errorf("DATA_DIR %q: %w", b.dataDir, err)
+				return fmt.Errorf("create data dir: %w", err)
-			}
-
-			// Creating and removing a file stops the start when no
-			// file can be created in DATA_DIR, instead of the first
-			// write of a report file failing after reports were
-			// answered 200. A full disk is not caught: the empty
-			// file is still created.
-			f, err := os.CreateTemp(b.dataDir, "")
-			if err != nil {
-				return fmt.Errorf("DATA_DIR %q: %w", b.dataDir, err)
-			}
-
-			err = errors.Join(f.Close(), os.Remove(f.Name()))
-			if err != nil {
-				return fmt.Errorf("DATA_DIR %q: %w", b.dataDir, err)
 			}
 
 			// Report files left by earlier runs count too, and are
 			// the first to be deleted to make room.
 			files, err := reportFiles(b.dataDir)
 			if err != nil {
-				return fmt.Errorf("DATA_DIR %q: %w", b.dataDir, err)
+				return err
 			}
 
 			b.mu.Lock()
@@ -177,7 +147,7 @@ func New(
 
 			b.mu.Unlock()
 
-			b.writers.Go(b.flushLoop)
+			go b.flushLoop()
 
 			return nil
 		},
@@ -188,14 +158,7 @@ func New(
 			var err error
 
 			b.stopOnce.Do(func() {
-				// Closing done ends flushLoop after any flush it is
-				// running. Wait for it and for the writes Append
-				// started, which the process exiting would cut off;
-				// one that fails puts its reports back in buf, for the
-				// final flush to write.
 				close(b.done)
-				b.writers.Wait()
-
 				err = b.flushLocked()
 			})
 
@@ -213,9 +176,8 @@ func New(
 // write of a report file failed, until a write succeeds again. If the
 // line would take usedBytes past maxBytes, the oldest report files are
 // deleted to make room; it stores nothing and returns ErrFull if that
-// cannot make room. If the buffer reaches the size threshold, it starts
+// cannot make room. If the buffer reaches the size threshold, it is
-// a write of the reports in the background (see flushAtThreshold),
+// drained and written to disk asynchronously.
-// unless one it started is still waiting.
 func (b *Buffer) Append(v any) error {
 	line, err := json.Marshal(v)
 	if err != nil {
@@ -245,9 +207,18 @@ func (b *Buffer) Append(v any) error {
 	b.buf.Write(line)
 	b.buf.WriteByte('\n')
 
-	if b.buf.Len() >= flushSizeThreshold &&
+	if b.buf.Len() >= flushSizeThreshold {
-		b.thresholdWriteWaiting.CompareAndSwap(false, true) {
+		data := b.drainBuf()
-		b.writers.Go(b.flushAtThreshold)
+		b.mu.Unlock()
+
+		go func() {
+			writeErr := b.writeFile(data)
+			if writeErr != nil {
+				b.log.Error("flush reports failed", "error", writeErr)
+			}
+		}()
+
+		return nil
 	}
 
 	b.mu.Unlock()
@@ -255,16 +226,6 @@ func (b *Buffer) Append(v any) error {
 	return nil
 }
 
-// LastWriteFailed reports whether the last write of a report file to
-// finish failed: false at start until a write fails, and false again
-// once a write succeeds. While it is true, Append refuses reports.
-func (b *Buffer) LastWriteFailed() bool {
-	b.mu.Lock()
-	defer b.mu.Unlock()
-
-	return b.writeErr != nil
-}
-
 // deleteOldestFiles deletes report files, oldest first, until n more
 // bytes fit under maxBytes. It deletes none when the reports waiting
 // to be written leave no room for n even with every file gone, since
@@ -315,28 +276,21 @@ func (b *Buffer) flushLoop() {
 	}
 }
 
-// flushLocked waits for any write of a report file under way, then
+// flushLocked acquires the lock, drains the buffer, and
-// writes the reports waiting in the buffer to a new one.
+// writes the data to a compressed file.
 func (b *Buffer) flushLocked() error {
-	b.writeMu.Lock()
+	b.mu.Lock()
-	defer b.writeMu.Unlock()
 
-	return b.writeFile()
+	if b.buf.Len() == 0 {
-}
+		b.mu.Unlock()
 
-// flushAtThreshold is the write Append starts when the buffer reaches
+		return nil
-// flushSizeThreshold. Once any write under way is done, it lets Append
-// start another and writes the reports waiting in the buffer.
-func (b *Buffer) flushAtThreshold() {
-	b.writeMu.Lock()
-	defer b.writeMu.Unlock()
-
-	b.thresholdWriteWaiting.Store(false)
-
-	err := b.writeFile()
-	if err != nil {
-		b.log.Error("flush reports failed", "error", err)
 	}
+
+	data := b.drainBuf()
+	b.mu.Unlock()
+
+	return b.writeFile(data)
 }
 
 // drainBuf copies the buffer contents and resets it.
@@ -349,22 +303,10 @@ func (b *Buffer) drainBuf() []byte {
 	return data
 }
 
-// writeFile takes the reports waiting in the buffer, if any, and writes
+// writeFile writes data, reports drained from the buffer, to a new
-// them to a new timestamped zstd-compressed JSONL file in the data
+// timestamped zstd-compressed JSONL file in the data directory. If the
-// directory. If the write fails, it puts the reports back in the
+// write fails, it puts the reports back in the buffer.
-// buffer. The caller must hold b.writeMu.
+func (b *Buffer) writeFile(data []byte) error {
-func (b *Buffer) writeFile() error {
-	b.mu.Lock()
-
-	if b.buf.Len() == 0 {
-		b.mu.Unlock()
-
-		return nil
-	}
-
-	data := b.drainBuf()
-	b.mu.Unlock()
-
 	// The timestamp comes first, so the names sort by time; the number
 	// after it tells apart files named in the same millisecond.
 	ts := b.now().UTC().Format("2006-01-02T15-04-05.000Z")
@@ -395,7 +337,14 @@ func (b *Buffer) writeFile() error {
 	b.usedBytes -= int64(len(data))
 	b.usedBytes += size
 	b.filesBytes += size
-	b.files = append(b.files, reportFile{name: name, size: size})
+
+	// At its place by name, not at the end: another write, of a newer
+	// file, may have completed while this one was being written.
+	i, _ := slices.BinarySearchFunc(b.files, name,
+		func(f reportFile, target string) int {
+			return strings.Compare(f.name, target)
+		})
+	b.files = slices.Insert(b.files, i, reportFile{name: name, size: size})
 
 	return nil
 }

internal/reportbuf/reportbuf_test.go

@@ -15,7 +15,6 @@ import (
 	"sync"
 	"sync/atomic"
 	"testing"
-	"testing/synctest"
 	"time"
 
 	"sneak.berlin/go/netwatch/internal/config"
@@ -108,236 +107,9 @@ func TestFailedFinalFlushFailsStop(t *testing.T) {
 	}
 }
 
-// TestUncreatableDataDirStopsStart sets DATA_DIR below a regular file,
+// startBuffer starts a Buffer through fx, as main does, with the
-// where no directory can be created, even by root, as the tests run in
+// DATA_DIR and DATA_DIR_MAX_BYTES the calling test has set.
-// the backend image. The start must fail with an error naming DATA_DIR
+func startBuffer(t *testing.T) *reportbuf.Buffer {
-// and its value, as the errors for the other settings do.
-func TestUncreatableDataDirStopsStart(t *testing.T) {
-	file := filepath.Join(t.TempDir(), "file")
-	writeBytes(t, file, 1)
-
-	dir := filepath.Join(file, "reports")
-	t.Setenv("DATA_DIR", dir)
-
-	app := fxtest.New(t,
-		fx.Provide(
-			globals.New,
-			logger.New,
-			config.New,
-			reportbuf.New,
-		),
-		fx.Invoke(func(*reportbuf.Buffer) {}),
-	)
-
-	err := app.Start(t.Context())
-	if err == nil {
-		t.Fatal("start succeeded with DATA_DIR below a regular file")
-	}
-
-	want := fmt.Sprintf("DATA_DIR %q: ", dir)
-	if !strings.Contains(err.Error(), want) {
-		t.Fatalf("start error = %q, want it to contain %q", err, want)
-	}
-}
-
-// TestUnwritableDataDirStopsStart sets DATA_DIR to /proc, which exists
-// and can be read, but where no file can be created, even by root, as
-// the tests run in the backend image: root ignores a directory the test
-// makes read-only. The start must fail with an error naming DATA_DIR and
-// its value, rather than the first write of a report file.
-func TestUnwritableDataDirStopsStart(t *testing.T) {
-	dir := "/proc"
-	t.Setenv("DATA_DIR", dir)
-
-	app := fxtest.New(t,
-		fx.Provide(
-			globals.New,
-			logger.New,
-			config.New,
-			reportbuf.New,
-		),
-		fx.Invoke(func(*reportbuf.Buffer) {}),
-	)
-
-	err := app.Start(t.Context())
-	if err == nil {
-		t.Fatal("start succeeded with DATA_DIR /proc")
-	}
-
-	want := fmt.Sprintf("DATA_DIR %q: ", dir)
-	if !strings.Contains(err.Error(), want) {
-		t.Fatalf("start error = %q, want it to contain %q", err, want)
-	}
-}
-
-// TestStopWaitsForPeriodicWrite holds open the write the periodic flush
-// starts, then stops the app. The stop must wait until the write is
-// released, and the report must then be in its file. The test runs in
-// a synctest bubble, whose clock moves on at once when every goroutine
-// in it is waiting, so the periodic flush does not take a minute.
-func TestStopWaitsForPeriodicWrite(t *testing.T) {
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	synctest.Test(t, func(t *testing.T) {
-		buf, app := startApp(t)
-
-		created := make(chan struct{})
-		release := make(chan struct{})
-
-		buf.OnFileCreated(func(*os.File) {
-			created <- struct{}{}
-
-			<-release
-		})
-
-		err := buf.Append(map[string]string{"id": "periodic"})
-		if err != nil {
-			t.Fatalf("append report: %v", err)
-		}
-
-		<-created
-
-		err = stopWhileHeld(t, app, release)
-		if err != nil {
-			t.Fatalf("stop: %v", err)
-		}
-
-		files, err := readReportFiles(dir)
-		if err != nil {
-			t.Fatalf("read report files: %v", err)
-		}
-
-		want := `{"id":"periodic"}` + "\n"
-		if len(files) != 1 || files[0] != want {
-			t.Fatalf("report files = %q, want one holding %q", files, want)
-		}
-	})
-}
-
-// TestStopWaitsForWriteAtSizeThreshold holds open the write Append
-// starts when the buffer reaches FlushSizeThreshold, then stops the
-// app. The stop must wait until the write is released, and the reports
-// must then be in its file.
-func TestStopWaitsForWriteAtSizeThreshold(t *testing.T) {
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	synctest.Test(t, func(t *testing.T) {
-		buf, app := startApp(t)
-
-		created := make(chan struct{})
-		release := make(chan struct{})
-
-		buf.OnFileCreated(func(*os.File) {
-			created <- struct{}{}
-
-			<-release
-		})
-
-		appended := appendToThreshold(t, buf)
-
-		<-created
-
-		err := stopWhileHeld(t, app, release)
-		if err != nil {
-			t.Fatalf("stop: %v", err)
-		}
-
-		files, err := readReportFiles(dir)
-		if err != nil {
-			t.Fatalf("read report files: %v", err)
-		}
-
-		if len(files) != 1 || files[0] != appended {
-			t.Fatalf("%d report files, want one holding the %d bytes "+
-				"appended", len(files), len(appended))
-		}
-	})
-}
-
-// TestFinalFlushWritesReportsOfFailedWrite holds open the write the
-// periodic flush starts, makes it fail, then stops the app. The stop
-// waits for the write, which puts its report back in the buffer, and
-// the final flush writes it, so the stop succeeds with nothing lost.
-func TestFinalFlushWritesReportsOfFailedWrite(t *testing.T) {
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	synctest.Test(t, func(t *testing.T) {
-		buf, app := startApp(t)
-
-		created := make(chan *os.File)
-		release := make(chan struct{})
-
-		buf.OnFileCreated(func(f *os.File) {
-			created <- f
-
-			<-release
-		})
-
-		err := buf.Append(map[string]string{"id": "failed"})
-		if err != nil {
-			t.Fatalf("append report: %v", err)
-		}
-
-		held := <-created
-
-		// Closing the file under the write makes the write fail.
-		_ = held.Close()
-
-		// The final flush's write goes through.
-		buf.OnFileCreated(func(*os.File) {})
-
-		err = stopWhileHeld(t, app, release)
-		if err != nil {
-			t.Fatalf("stop: %v", err)
-		}
-
-		files, err := readReportFiles(dir)
-		if err != nil {
-			t.Fatalf("read report files: %v", err)
-		}
-
-		want := `{"id":"failed"}` + "\n"
-		if len(files) != 1 || files[0] != want {
-			t.Fatalf("report files = %q, want one holding %q", files, want)
-		}
-	})
-}
-
-// stopWhileHeld stops app while a report file write is held open until
-// release is closed, and fails the test if the stop returns before
-// that. It then closes release and returns the stop's error. It must
-// be called in a synctest bubble.
-func stopWhileHeld(
-	t *testing.T,
-	app *fxtest.App,
-	release chan<- struct{},
-) error {
-	t.Helper()
-
-	stopped := make(chan error, 1)
-
-	go func() { stopped <- app.Stop(t.Context()) }()
-
-	// Wait returns once every other goroutine in the bubble is waiting:
-	// the stop has got as far as it can while the write is held.
-	synctest.Wait()
-
-	if len(stopped) != 0 {
-		t.Error("stop returned while a report file write was held open")
-	}
-
-	close(release)
-
-	return <-stopped
-}
-
-// startApp starts a Buffer through fx, as cli.RunServer does, with the
-// DATA_DIR and DATA_DIR_MAX_BYTES the calling test has set, and returns
-// it with the app, for tests that stop the app themselves.
-func startApp(t *testing.T) (*reportbuf.Buffer, *fxtest.App) {
 	t.Helper()
 
 	var buf *reportbuf.Buffer
@@ -355,16 +127,6 @@ func startApp(t *testing.T) (*reportbuf.Buffer, *fxtest.App) {
 	app.RequireStart()
 	t.Cleanup(app.RequireStop)
 
-	return buf, app
-}
-
-// startBuffer starts a Buffer through fx, as cli.RunServer does, with
-// the DATA_DIR and DATA_DIR_MAX_BYTES the calling test has set.
-func startBuffer(t *testing.T) *reportbuf.Buffer {
-	t.Helper()
-
-	buf, _ := startApp(t)
-
 	return buf
 }
 
@@ -581,62 +343,6 @@ func TestWrittenFilesDeletedToMakeRoom(t *testing.T) {
 	}
 }
 
-// TestWrittenFilesDeletedOldestFirst writes three report files, then
-// appends a report that fits only once one of them is deleted. The
-// first one written must be the one deleted.
-func TestWrittenFilesDeletedOldestFirst(t *testing.T) {
-	const maxBytes = 1000
-
-	report := map[string]string{"id": "written"}
-
-	t.Setenv("DATA_DIR", t.TempDir())
-	t.Setenv("DATA_DIR_MAX_BYTES", strconv.Itoa(maxBytes))
-
-	buf := startBuffer(t)
-
-	var written []string
-
-	buf.OnFileCreated(func(f *os.File) { written = append(written, f.Name()) })
-
-	for range 3 {
-		err := buf.Append(report)
-		if err != nil {
-			t.Fatalf("append report: %v", err)
-		}
-
-		err = buf.Flush()
-		if err != nil {
-			t.Fatalf("flush: %v", err)
-		}
-	}
-
-	// The three files hold the same report, so they are the same size.
-	info, err := os.Stat(written[0])
-	if err != nil {
-		t.Fatalf("stat %s: %v", written[0], err)
-	}
-
-	// A report that fits beside two of the files, so deleting one makes
-	// exactly the room it needs.
-	pad := maxBytes - 2*int(info.Size()) -
-		lineBytes(t, map[string]string{"id": ""})
-
-	err = buf.Append(map[string]string{"id": strings.Repeat("a", pad)})
-	if err != nil {
-		t.Fatalf("report that needs room: %v", err)
-	}
-
-	if exists(t, written[0]) {
-		t.Fatal("first report file written kept when room was needed")
-	}
-
-	for _, path := range written[1:] {
-		if !exists(t, path) {
-			t.Fatalf("%s deleted before the first report file written", path)
-		}
-	}
-}
-
 // TestFailedDeletionStillCounts makes deleting the oldest report file
 // fail. It is still there, so it still takes room, and the next oldest
 // is deleted in its place.
@@ -722,16 +428,17 @@ func TestFileDeletedByHandFreesRoom(t *testing.T) {
 	}
 }
 
-// TestFileBeingWrittenIsNeverDeleted holds the write of a report file
+// TestFileBeingWrittenIsNeverDeleted holds the write of one report file
-// open under a cap with room for two reports, then appends a second
+// open while a second write completes, then sends a report that needs
-// report and a third that needs room. The file being written is the
+// room. Deleting either file would make it, and the one being written is
-// only report file, and it is not deleted to make room, so the third
+// the older, but only the complete one may be deleted. Once the first
-// report is refused. Once the write is complete, its file is deleted
+// write is complete, its file is deleted when room is needed.
-// when room is needed.
 func TestFileBeingWrittenIsNeverDeleted(t *testing.T) {
 	report := map[string]string{"id": "writing"}
 
 	t.Setenv("DATA_DIR", t.TempDir())
+	// Room for two reports waiting to be written, but not for two
+	// beside a report file.
 	t.Setenv("DATA_DIR_MAX_BYTES", strconv.Itoa(2*lineBytes(t, report)))
 
 	buf := startBuffer(t)
@@ -756,25 +463,36 @@ func TestFileBeingWrittenIsNeverDeleted(t *testing.T) {
 
 	writing := <-created
 
-	// Errorf, not Fatalf, until the write is released, so that a
+	// Only the first write is held; the second goes through, and
+	// so do the writes after it, the final one at stop included.
+	var complete string
+
+	buf.OnFileCreated(func(f *os.File) { complete = f.Name() })
+
+	// Errorf, not Fatalf, until the first write is released, so that a
 	// failure here does not leave it held.
 	err = buf.Append(report)
 	if err != nil {
 		t.Errorf("second report: %v", err)
 	}
 
+	err = buf.Flush()
+	if err != nil {
+		t.Errorf("flush of the second report: %v", err)
+	}
+
 	err = buf.Append(report)
-	if !errors.Is(err, reportbuf.ErrFull) {
+	if err != nil {
-		t.Errorf("report that needs room: error = %v, want ErrFull", err)
+		t.Errorf("report that needs room: %v", err)
 	}
 
 	if !exists(t, writing) {
 		t.Error("report file deleted while it was being written")
 	}
 
-	// Only this write is held; the writes after it, the final one at
+	if exists(t, complete) {
-	// stop included, go through.
+		t.Error("complete report file kept, though room was needed")
-	buf.OnFileCreated(func(*os.File) {})
+	}
 
 	close(release)
 
@@ -783,11 +501,9 @@ func TestFileBeingWrittenIsNeverDeleted(t *testing.T) {
 		t.Fatalf("flush of the first report: %v", err)
 	}
 
-	// The second report still waits to be written, so this one fits
-	// only once the file just written is deleted.
 	err = buf.Append(report)
 	if err != nil {
-		t.Fatalf("report after the write was complete: %v", err)
+		t.Fatalf("report after the first write was complete: %v", err)
 	}
 
 	if exists(t, writing) {
@@ -929,82 +645,6 @@ func TestFailedWriteKeepsReportsAppendedDuringIt(t *testing.T) {
 	}
 }
 
-// TestFailedWritesKeepReportsInOrder holds a write open, then appends a
-// report that takes the buffer to FlushSizeThreshold, so that Append
-// starts a second write. The held write fails first, then the second,
-// which waited for it and took both reports. The next flush writes them
-// in the order they were appended, the held write's first.
-func TestFailedWritesKeepReportsInOrder(t *testing.T) {
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	buf := startBuffer(t)
-
-	created := make(chan struct{})
-	release := make(chan struct{})
-
-	// Each write is held until release is closed, then fails, as its
-	// file is closed under it.
-	buf.OnFileCreated(func(f *os.File) {
-		created <- struct{}{}
-
-		<-release
-
-		_ = f.Close()
-	})
-
-	err := buf.Append(map[string]string{"id": "held"})
-	if err != nil {
-		t.Fatalf("report of the held write: %v", err)
-	}
-
-	flushed := make(chan error)
-
-	go func() { flushed <- buf.Flush() }()
-
-	<-created
-
-	big := strings.Repeat("a", reportbuf.FlushSizeThreshold)
-
-	// Errorf, not Fatalf, until the held write is released, so that a
-	// failure here does not leave it held.
-	err = buf.Append(map[string]string{"id": big})
-	if err != nil {
-		t.Errorf("report that starts the second write: %v", err)
-	}
-
-	close(release)
-
-	err = <-flushed
-	if err == nil {
-		t.Error("held write succeeded, though its file was closed under it")
-	}
-
-	// The second write has created its file, so it has taken the
-	// reports.
-	<-created
-
-	// Writes from here on, the final one at stop included, succeed.
-	buf.OnFileCreated(func(*os.File) {})
-
-	// Flush waits for the second write to fail before it writes.
-	err = buf.Flush()
-	if err != nil {
-		t.Fatalf("flush after the failed writes: %v", err)
-	}
-
-	files, err := readReportFiles(dir)
-	if err != nil {
-		t.Fatalf("read report files: %v", err)
-	}
-
-	want := `{"id":"held"}` + "\n" + `{"id":"` + big + `"}` + "\n"
-	if len(files) != 1 || files[0] != want {
-		t.Fatalf("%d report files, want one holding the held write's "+
-			"report, then the second one", len(files))
-	}
-}
-
 // TestReportsRefusedWhileWritesFail posts reports through the report
 // handler, as the page does. Once a write has failed, a report is
 // refused with 500 until a write succeeds again; the reports taken
@@ -1074,54 +714,9 @@ func TestReportsRefusedWhileWritesFail(t *testing.T) {
 	}
 }
 
-// TestHealthCheckFailsWhileWritesFail asks the health check handler
-// for its answer around a failed write. It answers 200 with
-// "status":"ok" at start, 503 with "status":"error" from the failed
-// write until a write succeeds, and 200 with "status":"ok" again after.
-func TestHealthCheckFailsWhileWritesFail(t *testing.T) {
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	buf, h := startBufferWithHandlers(t)
-
-	checkHealthCheck(t, h, "at start", http.StatusOK, "ok")
-
-	// A flush writes a file only when a report is waiting.
-	err := buf.Append(map[string]string{"id": "kept"})
-	if err != nil {
-		t.Fatalf("append: %v", err)
-	}
-
-	// With the data directory gone, the write has nowhere to go.
-	err = os.Remove(dir)
-	if err != nil {
-		t.Fatalf("remove data dir: %v", err)
-	}
-
-	err = buf.Flush()
-	if err == nil {
-		t.Fatal("flush succeeded with the data directory gone")
-	}
-
-	checkHealthCheck(t, h, "after the failed write",
-		http.StatusServiceUnavailable, "error")
-
-	err = os.Mkdir(dir, 0o750)
-	if err != nil {
-		t.Fatalf("make data dir: %v", err)
-	}
-
-	err = buf.Flush()
-	if err != nil {
-		t.Fatalf("flush with the data directory back: %v", err)
-	}
-
-	checkHealthCheck(t, h, "after a write succeeded", http.StatusOK, "ok")
-}
-
 // startBufferWithHandlers starts a Buffer and the Handlers that store
-// reports in it through fx, as cli.RunServer does, with the DATA_DIR
+// reports in it through fx, as main does, with the DATA_DIR the calling
-// the calling test has set.
+// test has set.
 func startBufferWithHandlers(
 	t *testing.T,
 ) (*reportbuf.Buffer, *handlers.Handlers) {
@@ -1166,39 +761,6 @@ func postReport(t *testing.T, h *handlers.Handlers, clientID string) int {
 	return rec.Code
 }
 
-// checkHealthCheck asks the health check handler for its answer, and
-// fails the test, saying when it asked, unless the answer has status
-// code wantCode and a "status" field of wantStatus.
-func checkHealthCheck(
-	t *testing.T,
-	h *handlers.Handlers,
-	when string,
-	wantCode int,
-	wantStatus string,
-) {
-	t.Helper()
-
-	rec := httptest.NewRecorder()
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodGet, "/.well-known/healthcheck", http.NoBody)
-	h.HandleHealthCheck().ServeHTTP(rec, req)
-
-	var body struct {
-		Status string `json:"status"`
-	}
-
-	err := json.Unmarshal(rec.Body.Bytes(), &body)
-	if err != nil {
-		t.Fatalf("health check %s: body not JSON: %v (%q)",
-			when, err, rec.Body.String())
-	}
-
-	if rec.Code != wantCode || body.Status != wantStatus {
-		t.Fatalf("health check %s: %d with status %q, want %d with %q",
-			when, rec.Code, body.Status, wantCode, wantStatus)
-	}
-}
-
 // TestConcurrentAppendsStopAtCap appends from many goroutines at once
 // with room for exactly roomFor reports: exactly that many must be
 // taken, which holds only if Append checks and counts each report
@@ -1330,132 +892,6 @@ func TestFlushAtSizeThreshold(t *testing.T) {
 
 	buf := startBuffer(t)
 
-	appended := appendToThreshold(t, buf)
-
-	// Append writes the file in the background, so wait for it.
-	deadline := time.Now().Add(10 * time.Second)
-
-	for {
-		files, err := readReportFiles(dir)
-		if err == nil && len(files) == 1 && files[0] == appended {
-			return
-		}
-
-		if time.Now().After(deadline) {
-			t.Fatalf("%d report files (error: %v), want one holding the "+
-				"%d bytes appended", len(files), err, len(appended))
-		}
-
-		time.Sleep(10 * time.Millisecond)
-	}
-}
-
-// TestEachSizeThresholdStartsAWrite reaches FlushSizeThreshold twice,
-// with no call to Flush and the periodic flush a minute away. Append
-// must start a write each time, so that the reports end up in two
-// report files. The test runs in a synctest bubble, so that
-// synctest.Wait returns once each write is done.
-func TestEachSizeThresholdStartsAWrite(t *testing.T) {
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	synctest.Test(t, func(t *testing.T) {
-		buf := startBuffer(t)
-
-		var appended string
-
-		for range 2 {
-			appended = appendToThreshold(t, buf)
-
-			synctest.Wait()
-		}
-
-		files, err := readReportFiles(dir)
-		if err != nil {
-			t.Fatalf("read report files: %v", err)
-		}
-
-		if !slices.Equal(files, []string{appended, appended}) {
-			t.Fatalf("%d report files, want two, each holding the %d "+
-				"bytes appended to reach the threshold",
-				len(files), len(appended))
-		}
-	})
-}
-
-// TestAppendStartsOneWaitingWrite holds a write open, then appends two
-// reports of FlushSizeThreshold bytes each. Append starts a write at
-// the first, which waits for the held one, and none at the second,
-// since that write is still waiting. Every write fails, so a write
-// started at the second report would find the reports back in the
-// buffer and try them again: once the held write is released, two
-// writes must have been started, the held one and one more.
-func TestAppendStartsOneWaitingWrite(t *testing.T) {
-	t.Setenv("DATA_DIR", t.TempDir())
-
-	synctest.Test(t, func(t *testing.T) {
-		buf := startBuffer(t)
-
-		var writes atomic.Int64
-
-		release := make(chan struct{})
-
-		// Each write is held until release is closed, then fails, as its
-		// file is closed under it.
-		buf.OnFileCreated(func(f *os.File) {
-			writes.Add(1)
-
-			<-release
-
-			_ = f.Close()
-		})
-
-		err := buf.Append(map[string]string{"id": "one-waiting"})
-		if err != nil {
-			t.Fatalf("report of the held write: %v", err)
-		}
-
-		go func() { _ = buf.Flush() }()
-
-		// Wait returns once the flush's write is held.
-		synctest.Wait()
-
-		big := map[string]string{
-			"id": strings.Repeat("a", reportbuf.FlushSizeThreshold),
-		}
-
-		// Errorf, not Fatalf, until the held write is released, so that a
-		// failure here does not leave it held.
-		for range 2 {
-			err = buf.Append(big)
-			if err != nil {
-				t.Errorf("report of FlushSizeThreshold bytes: %v", err)
-			}
-		}
-
-		close(release)
-
-		// Wait returns once every write started is done.
-		synctest.Wait()
-
-		started := writes.Load()
-
-		// Writes from here on, the final one at stop included, succeed.
-		buf.OnFileCreated(func(*os.File) {})
-
-		if started != 2 {
-			t.Fatalf("%d writes started, want 2: the held one and one "+
-				"at the threshold", started)
-		}
-	})
-}
-
-// appendToThreshold appends reports to buf until it holds
-// FlushSizeThreshold bytes, so that the last append starts writing them
-// to a report file, and returns the lines appended.
-func appendToThreshold(t *testing.T, buf *reportbuf.Buffer) string {
-	t.Helper()
-
 	// Large reports, so the threshold takes a few hundred appends.
 	pad := strings.Repeat("a", 64<<10)
 
@@ -1478,7 +914,22 @@ func appendToThreshold(t *testing.T, buf *reportbuf.Buffer) string {
 		appended.WriteByte('\n')
 	}
 
-	return appended.String()
+	// Append writes the file in the background, so wait for it.
+	deadline := time.Now().Add(10 * time.Second)
+
+	for {
+		files, err := readReportFiles(dir)
+		if err == nil && len(files) == 1 && files[0] == appended.String() {
+			return
+		}
+
+		if time.Now().After(deadline) {
+			t.Fatalf("%d report files (error: %v), want one holding the "+
+				"%d bytes appended", len(files), err, appended.Len())
+		}
+
+		time.Sleep(10 * time.Millisecond)
+	}
 }
 
 // reportFilesBytes returns the total size of the report files in dir.
@@ -1595,3 +1046,85 @@ func hasReportFile(t *testing.T, dir string) bool {
 
 	return false
 }
+
+// TestFilesDeletedOldestFirstWhenWritesOverlap holds the write of an
+// older report file open until a newer one's write completes, then
+// releases it. When room is needed, the older file is deleted first,
+// though its write was the last to complete.
+func TestFilesDeletedOldestFirstWhenWritesOverlap(t *testing.T) {
+	const maxBytes = 1000
+
+	report := map[string]string{"id": "overlap"}
+
+	t.Setenv("DATA_DIR", t.TempDir())
+	t.Setenv("DATA_DIR_MAX_BYTES", strconv.Itoa(maxBytes))
+
+	buf := startBuffer(t)
+
+	created := make(chan string)
+	release := make(chan struct{})
+
+	buf.OnFileCreated(func(f *os.File) {
+		created <- f.Name()
+
+		<-release
+	})
+
+	err := buf.Append(report)
+	if err != nil {
+		t.Fatalf("older report: %v", err)
+	}
+
+	flushed := make(chan error)
+
+	go func() { flushed <- buf.Flush() }()
+
+	older := <-created
+
+	// Only the older write is held; the newer one goes through, and
+	// so do the writes after it, the final one at stop included.
+	var newer string
+
+	buf.OnFileCreated(func(f *os.File) { newer = f.Name() })
+
+	// Errorf, not Fatalf, until the older write is released, so that a
+	// failure here does not leave it held.
+	err = buf.Append(report)
+	if err != nil {
+		t.Errorf("newer report: %v", err)
+	}
+
+	err = buf.Flush()
+	if err != nil {
+		t.Errorf("flush of the newer report: %v", err)
+	}
+
+	close(release)
+
+	err = <-flushed
+	if err != nil {
+		t.Fatalf("flush of the older report: %v", err)
+	}
+
+	info, err := os.Stat(newer)
+	if err != nil {
+		t.Fatalf("stat %s: %v", newer, err)
+	}
+
+	// A report that fits beside the newer file alone, so deleting the
+	// older one makes exactly the room it needs.
+	pad := maxBytes - int(info.Size()) - lineBytes(t, map[string]string{"id": ""})
+
+	err = buf.Append(map[string]string{"id": strings.Repeat("a", pad)})
+	if err != nil {
+		t.Fatalf("report that needs room: %v", err)
+	}
+
+	if exists(t, older) {
+		t.Fatal("older report file kept when room was needed")
+	}
+
+	if !exists(t, newer) {
+		t.Fatal("newer report file deleted before the older one")
+	}
+}

internal/server/routes_test.go

@@ -22,9 +22,9 @@ import (
 	"go.uber.org/fx/fxtest"
 )
 
-// newServer builds a Server from the same constructors as
+// newServer builds a Server from the same constructors as main,
-// cli.RunServer, configured from the environment. It is never started,
+// configured from the environment. It is never started, so nothing
-// so nothing listens.
+// listens.
 func newServer(t *testing.T) *server.Server {
 	t.Helper()
 

internal/server/server.go

@@ -79,7 +79,7 @@ func New(
 			s.SetupRoutes()
 			s.httpServer = s.newHTTPServer()
 
-			go func() { s.listenAndServe() }()
+			go s.listenAndServe()
 
 			return nil
 		},

package.json

@@ -1,6 +1,6 @@
 {
     "name": "netwatch",
-    "private": true,
+    "version": "1.0.0",
     "description": "Real-time network latency monitor SPA",
     "type": "module",
     "scripts": {

script/add-dependency

@@ -23,8 +23,8 @@ main() {
     "" | -* | *[[:space:]]*) usage ;;
     esac
     cd "$ROOT"
-    "$ROOT/script/yarn" add --dev "$1"
+    yarn add --dev "$1"
-    "$ROOT/script/yarn" install --frozen-lockfile
+    yarn install --frozen-lockfile
 }
 
 main "$@"

script/bootstrap

@@ -3,14 +3,11 @@
 # this repo. Idempotent: every install is guarded by a check so already
 # installed tools are skipped. Base tooling comes from nix, apt, brew,
 # or apk (detected in that order); assumes nothing is present. Node is
-# used directly only if it has the major version of NODE_VERSION and is
+# used directly if it is at least NODE_MIN_VERSION; otherwise it is
-# at least NODE_MIN_VERSION; otherwise NODE_VERSION is installed via nvm
+# installed at a pinned version via nvm (installing nvm itself first,
-# (installing nvm itself first, from a hash-verified release archive,
+# from a hash-verified release archive, never curl | sh). Go, with its
-# never curl | sh). Yarn is used directly only if it is exactly
+# gofmt, is used directly only if it is exactly GO_VERSION; otherwise
-# YARN_VERSION; otherwise that version is prepared through corepack,
+# that release is installed from its hash-verified archive.
-# or installed with npm where there is no corepack.
-# Go, with its gofmt, is used directly only if it is exactly GO_VERSION;
-# otherwise that release is installed from its hash-verified archive.
 #
 # What this script installs outside the system package manager lives
 # under $HOME and is linked into ~/.local/bin, where make and the git
@@ -145,63 +142,32 @@ ensure_nvm() {
     rm -rf "$tmp"
 }
 
-# node_ok: the node on PATH has the major version of NODE_VERSION and is
+# node_ok: the node on PATH is at least NODE_MIN_VERSION. node itself
-# at least NODE_MIN_VERSION. Only the major is compared with the pin,
+# compares the two: major, then minor, then patch.
-# as REPO_POLICIES.md asks. node itself compares the versions: major,
-# then minor, then patch. A node that fails does not pass.
-# script/bootstrap and script/yarn carry this function unchanged.
 node_ok() {
-    if ! command -v node >/dev/null 2>&1; then return 1; fi
+    if missing node; then return 1; fi
     node -e '
         const have = process.versions.node.split(".").map(Number);
         const want = process.argv[1].split(".").map(Number);
-        const pinned = process.argv[2].split(".").map(Number);
-        if (have[0] !== pinned[0]) process.exit(1);
         for (let i = 0; i < 3; i++) {
             if (have[i] !== want[i]) process.exit(have[i] > want[i] ? 0 : 1);
         }
-    ' "$NODE_MIN_VERSION" "$NODE_VERSION"
+    ' "$NODE_MIN_VERSION"
 }
 
 # ensure_node: unless node_ok, install NODE_VERSION and link its node.
-# Afterwards node is looked up through PATH again and must pass node_ok.
 ensure_node() {
-    if node_ok; then
+    if node_ok; then return 0; fi
-        echo "bootstrap: using node $(node --version)"
-        return 0
-    fi
     ensure_nvm
     nvm_sh "nvm install $NODE_VERSION"
     link_bin "$HOME/.nvm/versions/node/v$NODE_VERSION/bin/node" node
-    hash -r
-    if ! node_ok; then
-        echo "bootstrap: after installing node $NODE_VERSION through nvm," >&2
-        echo "  the node on PATH, $(command -v node), is not it" >&2
-        exit 1
-    fi
-    echo "bootstrap: installed node $(node --version)"
 }
 
-# yarn_ok: yarn --version on PATH prints exactly YARN_VERSION, compared
+# ensure_yarn: corepack writes its shims (pnpm and yarnpkg as well as
-# over the whole version. A yarn that fails or prints anything else does
+# yarn) into $TOOLCHAIN rather than next to itself, and the npm fallback
-# not pass.
+# installs there too; only yarn is linked.
-yarn_ok() {
-    if missing yarn; then return 1; fi
-    version="$(yarn --version 2>/dev/null)" || return 1
-    [ "$version" = "$YARN_VERSION" ]
-}
-
-# ensure_yarn: unless yarn_ok, prepare YARN_VERSION and link its yarn.
-# corepack writes its shims (pnpm and yarnpkg as well as yarn) into
-# $TOOLCHAIN rather than next to itself, and the npm fallback installs
-# there too; only yarn is linked. Afterwards yarn is looked up through
-# PATH again and must pass yarn_ok, so another yarn that hides the link
-# stops bootstrap.
 ensure_yarn() {
-    if yarn_ok; then
+    if ! missing yarn; then return 0; fi
-        echo "bootstrap: using yarn $(yarn --version)"
-        return 0
-    fi
     shims="$TOOLCHAIN/corepack-shims"
     mkdir -p "$shims"
     if ! missing corepack; then
@@ -216,13 +182,6 @@ ensure_yarn() {
         shims="$TOOLCHAIN/npm-global/bin"
     fi
     link_bin "$shims/yarn" yarn
-    hash -r
-    if ! yarn_ok; then
-        echo "bootstrap: after installing yarn $YARN_VERSION in $shims," >&2
-        echo "  the yarn on PATH, $(command -v yarn), does not report it" >&2
-        exit 1
-    fi
-    echo "bootstrap: installed yarn $(yarn --version)"
 }
 
 # go_ok: the go on PATH has its gofmt beside it (a Go release ships the

script/build

@@ -8,12 +8,11 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$ROOT/script/yarn" build
+    yarn build
 
-    # VERSION comes from the environment. Unset or empty, it is
+    # VERSION comes from the environment. Unset or empty, it is git
-    # `git describe --tags --always --dirty`, as in script/docker, or
+    # describe, or "dev" where there is no git or no repository history.
-    # "dev" where there is no git or no repository history.
+    version="${VERSION:-$(git describe --always --dirty 2>/dev/null || echo dev)}"
-    version="${VERSION:-$(git describe --tags --always --dirty 2>/dev/null || echo dev)}"
 
     CGO_ENABLED=0 go build -trimpath \
         -ldflags "-s -w -X main.Version=$version" \

script/cibuild

@@ -2,12 +2,9 @@
 # script/cibuild: run the CI build. It bootstraps first: a CI runner
 # checks out and runs this and nothing else, and script/fmt-check runs
 # the formatter on the host, which a pristine checkout cannot do.
-# A new CACHEBUST value reruns every RUN step after the ARG CACHEBUST
+# --no-cache for the same reason as script/docker: the gate phases the
-# line, since a cached gate phase is a check that did not run; unlike
+# final stage depends on are RUN steps, and a cached one is a check that
-# --no-cache, it keeps the layers above that line and the cache mounts.
+# did not run.
-# This relies on every stage of the Dockerfile declaring ARG CACHEBUST
-# before every step that lints, tests or compiles; a stage without that
-# line is served from cache on an unchanged tree, with no warning.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -17,17 +14,15 @@ main() {
     cd "$ROOT"
     "$SCRIPT_DIR/bootstrap"
     "$SCRIPT_DIR/check"
-    # The version and the tag each get their own line: a failing
+    # Own line: a failing command substitution inside an argument does
-    # command substitution inside an argument does not trip `set -e`,
+    # not trip `set -e`, so the inline form degrades silently to an
-    # so the inline form degrades silently to an empty constant. The
+    # empty constant. The VERSION build argument takes precedence over
-    # VERSION build argument takes precedence over the version a build
+    # the version a build stage derives from the .git in the context.
-    # stage derives from the .git in the context.
     version="$(git describe --tags --always --dirty 2>/dev/null || true)"
     [ -n "$version" ] || version="unknown"
-    tag="$("$SCRIPT_DIR/projectname")"
+    docker build --no-cache \
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
         --build-arg VERSION="$version" \
-        -t "$tag" .
+        -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/dev

@@ -7,7 +7,7 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$ROOT/script/yarn" dev
+    yarn dev
 }
 
 main "$@"

script/docker

@@ -1,12 +1,8 @@
 #!/bin/sh
 # script/docker: build the Docker image tagged with the project name.
 # Identical in all repos; the tag comes from script/projectname.
-# A new CACHEBUST value reruns every RUN step after the ARG CACHEBUST
+# --no-cache because the gate phases the final stage depends on are RUN
-# line, since a cached gate phase is a check that did not run; unlike
+# steps, and a cached one is a check that did not run.
-# --no-cache, it keeps the layers above that line and the cache mounts.
-# This relies on every stage of the Dockerfile declaring ARG CACHEBUST
-# before every step that lints, tests or compiles; a stage without that
-# line is served from cache on an unchanged tree, with no warning.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -14,17 +10,15 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    # The version and the tag each get their own line: a failing
+    # Own line: a failing command substitution inside an argument does
-    # command substitution inside an argument does not trip `set -e`,
+    # not trip `set -e`, so the inline form degrades silently to an
-    # so the inline form degrades silently to an empty constant. The
+    # empty constant. The VERSION build argument takes precedence over
-    # VERSION build argument takes precedence over the version a build
+    # the version a build stage derives from the .git in the context.
-    # stage derives from the .git in the context.
     version="$(git describe --tags --always --dirty 2>/dev/null || true)"
     [ -n "$version" ] || version="unknown"
-    tag="$("$SCRIPT_DIR/projectname")"
+    docker build --no-cache \
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
         --build-arg VERSION="$version" \
-        -t "$tag" .
+        -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/frontend-fmt

@@ -10,7 +10,7 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$ROOT/script/yarn" prettier --write '**/*.{js,css,html,md}'
+    yarn prettier --write '**/*.{js,css,html,md}'
 }
 
 main "$@"

script/frontend-fmt-check

@@ -7,7 +7,7 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$ROOT/script/yarn" prettier --check '**/*.{js,css,html,md}'
+    yarn prettier --check '**/*.{js,css,html,md}'
 }
 
 main "$@"

script/frontend-test

@@ -2,10 +2,9 @@
 # script/frontend-test: run the frontend test suite on the host: the
 # unit tests in test/unit/, through the test script in package.json,
 # then the production build, which fails on broken code. make test runs
-# the same tests in the frontend-test stage of Dockerfile, and the image
+# the same in the frontend stage of Dockerfile. The tests print a dot
-# build runs the production build in its frontend-build stage. The tests
+# each; if any fails, they run again with every test listed, and the
-# print a dot each; if any fails, they run again with every test listed,
+# script fails even if that run passes. NODE_OPTIONS chooses the
-# and the script fails even if that run passes. NODE_OPTIONS chooses the
 # reporter because yarn adds its arguments after the test files, where
 # node would take a reporter option for one more file.
 set -eu
@@ -14,14 +13,12 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    NODE_OPTIONS=--test-reporter=dot \
+    NODE_OPTIONS=--test-reporter=dot timeout 90 yarn --silent run test || {
-        timeout 90 "$ROOT/script/yarn" --silent run test || {
         echo "--- Rerunning with every test listed for details ---"
-        NODE_OPTIONS=--test-reporter=spec \
+        NODE_OPTIONS=--test-reporter=spec timeout 90 yarn --silent run test
-            timeout 90 "$ROOT/script/yarn" --silent run test
         exit 1
     }
-    timeout 30 "$ROOT/script/yarn" build
+    timeout 30 yarn build
 }
 
 main "$@"

script/frontend-viewport-test

@@ -7,8 +7,6 @@
 # headless Chrome at it over CDP, and asserts on computed layout at every
 # viewport width derived from the app's own CSS. See
 # test/viewport/README.md for what this covers and what it cannot.
-# Before the browser starts, it checks that the page is served with
-# Cache-Control: no-cache and Content-Security-Policy.
 #
 # Deliberately not part of script/check: it needs Docker and takes far
 # longer than the 20s budget make test has to stay inside.
@@ -77,32 +75,6 @@ main() {
         -v "$ROOT/configs/security-headers.conf:/etc/nginx/security-headers.conf:ro" \
         "$SERVER_IMAGE" > /dev/null
 
-    # The page, and /no-such-page, which location / answers with the
-    # page through its try_files fallback, must go out with
-    # Cache-Control: no-cache. That add_header in its location drops the
-    # server's own unless the location includes the security headers
-    # again; only Content-Security-Policy is checked, as it comes from
-    # the same file as the rest. curl tries up to ten more times, a
-    # second apart, while nginx starts. It runs without -S, which would
-    # print an error for every failed attempt, even when a later one
-    # succeeds.
-    for path in / /no-such-page; do
-        if ! headers="$(docker exec "$SERVER" curl -s -o /dev/null -D - \
-            --retry 10 --retry-connrefused --retry-delay 1 \
-            "http://127.0.0.1:8080$path")"; then
-            echo "frontend-viewport-test: nginx did not answer $path" >&2
-            exit 1
-        fi
-        headers="$(printf '%s\n' "$headers" | tr -d '\r')"
-        if ! printf '%s\n' "$headers" | grep -qix 'Cache-Control: no-cache' ||
-            ! printf '%s\n' "$headers" | grep -qi '^Content-Security-Policy:'; then
-            echo "frontend-viewport-test: $path needs" \
-                "Cache-Control: no-cache and Content-Security-Policy; got:" >&2
-            printf '%s\n' "$headers" >&2
-            exit 1
-        fi
-    done
-
     # The image's own entrypoint already exposes CDP on 9222 and passes
     # --no-sandbox, so only extra flags belong here; re-specifying the
     # debugging port collides with it and leaves the endpoint bound to

script/lint

@@ -5,14 +5,9 @@
 # make its answer untrustworthy.
 #
 # The phase is not the last stage in the file, so it is built only when
-# --target names it. A new CACHEBUST value reruns every RUN step after
+# --target names it. --no-cache because a cached lint layer is a lint
-# the ARG CACHEBUST line, since a cached lint layer is a lint that did
+# that did not run. The tag makes each build replace the previous image
-# not run; unlike --no-cache, it keeps the layers above that line and
+# instead of leaving a dangling one behind.
-# the cache mounts. This relies on every stage of the Dockerfile
-# declaring ARG CACHEBUST before every step that lints, tests or
-# compiles; a stage without that line is served from cache on an
-# unchanged tree, with no warning.
-# --output type=cacheonly writes no image, since nothing uses one.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -20,9 +15,9 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
         --target lint \
-        --output type=cacheonly .
+        -t "$("$SCRIPT_DIR/projectname")-lint" .
 }
 
 main "$@"

script/test

@@ -2,13 +2,8 @@
 # script/test: run the test suite. Testing is a phase of the Dockerfile
 # and this builds that phase alone, on the same terms as script/lint:
 # --target because a phase that is not the last stage is built only when
-# named, and a new CACHEBUST value because a cached test layer is a test
+# named, --no-cache because a cached test layer is a test that did not
-# that did not run; unlike --no-cache, it keeps the layers above the ARG
+# run, and a tag so each build replaces the previous image.
-# CACHEBUST line and the cache mounts. This relies on every stage of the
-# Dockerfile declaring ARG CACHEBUST before every step that lints, tests
-# or compiles; a stage without that line is served from cache on an
-# unchanged tree, with no warning. --output type=cacheonly writes no
-# image, since nothing uses one.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -16,9 +11,9 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
         --target test \
-        --output type=cacheonly .
+        -t "$("$SCRIPT_DIR/projectname")-test" .
 }
 
 main "$@"

script/yarn

@@ -1,55 +0,0 @@
-#!/bin/sh
-# script/yarn: run yarn with the given arguments under the node
-# script/bootstrap would use. Every script that runs yarn on the host
-# runs it through this one, except script/bootstrap, which picks its
-# own node and yarn.
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-# Must match the pins in script/bootstrap.
-NODE_VERSION="22.17.0"
-NODE_MIN_VERSION="22.13.0"
-
-# node_ok: the node on PATH has the major version of NODE_VERSION and is
-# at least NODE_MIN_VERSION. Only the major is compared with the pin,
-# as REPO_POLICIES.md asks. node itself compares the versions: major,
-# then minor, then patch. A node that fails does not pass.
-# script/bootstrap and script/yarn carry this function unchanged.
-node_ok() {
-    if ! command -v node >/dev/null 2>&1; then return 1; fi
-    node -e '
-        const have = process.versions.node.split(".").map(Number);
-        const want = process.argv[1].split(".").map(Number);
-        const pinned = process.argv[2].split(".").map(Number);
-        if (have[0] !== pinned[0]) process.exit(1);
-        for (let i = 0; i < 3; i++) {
-            if (have[i] !== want[i]) process.exit(have[i] > want[i] ? 0 : 1);
-        }
-    ' "$NODE_MIN_VERSION" "$NODE_VERSION"
-}
-
-# Run the yarn script/bootstrap installed: the yarn on PATH when the
-# node on PATH passes node_ok, and otherwise yarn under the pinned node
-# in nvm. nvm is a bash script, hence the subshell.
-run_yarn() {
-    if node_ok && command -v yarn >/dev/null 2>&1; then
-        exec yarn "$@"
-    fi
-    if node_ok || [ ! -s "$HOME/.nvm/nvm.sh" ]; then
-        echo "script/yarn: no yarn; run script/bootstrap first" >&2
-        exit 1
-    fi
-    exec bash -c '. "$HOME/.nvm/nvm.sh" && nvm use "$1" >/dev/null &&
-        shift && exec yarn "$@"' bash "$NODE_VERSION" "$@"
-}
-
-main() {
-    cd "$ROOT"
-    # script/bootstrap links the node and yarn it installs into
-    # ~/.local/bin, which the shell that called it may not have on PATH.
-    PATH="$HOME/.local/bin:$PATH"
-    run_yarn "$@"
-}
-
-main "$@"

test/unit/main.test.js

@@ -6,7 +6,6 @@ import { beforeEach, test } from "node:test";
 import assert from "node:assert/strict";
 import {
     AppState,
-    buildUI,
     CONFIG,
     greyOutUI,
     hostRowHTML,
@@ -14,26 +13,20 @@ import {
     humanDuration,
     latencyClass,
     latencyHex,
-    log,
     measureLatency,
     Reporter,
     tick,
-    updateClocks,
-    updateSummary,
 } from "../../web/src/main.js";
 
 // There is no page here, so the tests stand in for it. The debug log looks
-// for its panel by id and finds none, an element the page creates is a
+// for its panel by id and finds none. Each element of a host's row that
-// plain object, and no frame the page asks for ever comes. Each element of
+// tick or greyOutUI draws into is a plain object, made the first time a
-// a host's row that tick or greyOutUI draws into is a plain object, made
+// test looks it up and kept in elements under its selector until the next
-// the first time a test looks it up and kept in elements under its
+// test starts. As on a page, writing its text replaces its markup; the
-// selector until the next test starts. As on a page, writing its text
+// status dot greyOutUI looks for in it is not there. Drawing a sparkline
-// replaces its markup; the status dot greyOutUI looks for in it is not
+// does nothing; it looks for the pixel ratio on window and finds none. In
-// there. Drawing a sparkline does nothing; it looks for the pixel ratio on
+// each test, console.error and console.info print nothing and keep what
-// window and finds none. The commit the page's footer names, which
+// they are given.
-// vite.config.js fills in when it builds the page, is blank. In each test,
-// console.error and console.info print nothing and keep what they are
-// given.
 const doNothing = () => {};
 let elements;
 beforeEach((t) => {
@@ -53,13 +46,8 @@ const canvasContext = {
     arc: doNothing,
 };
 globalThis.window = {};
-globalThis.requestAnimationFrame = doNothing;
-globalThis.cancelAnimationFrame = doNothing;
-globalThis.__COMMIT_HASH__ = "";
-globalThis.__COMMIT_FULL__ = "";
 globalThis.document = {
     getElementById: () => null,
-    createElement: () => ({}),
     querySelector: (selector) =>
         (elements[selector] ??= {
             getContext: () => canvasContext,
@@ -83,11 +71,6 @@ function statusText(state, host) {
     return elements[`.status-text[data-host="${index}"]`]?.innerHTML;
 }
 
-// What this test wrote to the browser console with console[method].
-function consoleLines(method) {
-    return console[method].mock.calls.map((call) => call.arguments[0]);
-}
-
 // Mocks the clock for test t, so that a check lasting seconds takes no real
 // time, and replaces fetch with targets that each answer after
 // answerAfter(url) milliseconds of that clock, or never when that is
@@ -207,10 +190,9 @@ test("at a 30000ms interval, a target answering after 1000ms shows in its row wh
 });
 
 // In the next three tests, the answering target's check is still waiting
-// when something happens after which its result must not be recorded or
+// when something happens after which its result must not show.
-// show in its row, and the check must write nothing to the console.
 
-test("at a 30000ms interval, a check still waiting when its round is given up is not recorded and does not show in its row", async (t) => {
+test("at a 30000ms interval, a check still waiting when its round is given up does not show in its row", async (t) => {
     CONFIG.updateInterval = 30000;
     const state = new AppState([
         { name: "Answering", url: "https://answering.test" },
@@ -226,13 +208,9 @@ test("at a 30000ms interval, a check still waiting when its round is given up is
     roundChecks.abort();
     assert.notEqual(await settled(round), "still waiting");
     assert.equal(latencyFigure(state, answering), undefined);
-    assert.deepEqual(answering.history, []);
-    assert.equal(answering.status, "pending");
-    assert.deepEqual(consoleLines("error"), []);
-    assert.deepEqual(consoleLines("info"), []);
 });
 
-test("at a 30000ms interval, a check still waiting when the user pauses is not recorded and does not show in its row", async (t) => {
+test("at a 30000ms interval, a check still waiting when the user pauses does not show in its row", async (t) => {
     CONFIG.updateInterval = 30000;
     const state = new AppState([
         { name: "Answering", url: "https://answering.test" },
@@ -247,13 +225,9 @@ test("at a 30000ms interval, a check still waiting when the user pauses is not r
     t.mock.timers.tick(500);
     assert.equal(await settled(round), "still waiting");
     assert.equal(latencyFigure(state, answering), undefined);
-    assert.deepEqual(answering.history, []);
-    assert.equal(answering.status, "pending");
-    assert.deepEqual(consoleLines("error"), []);
-    assert.deepEqual(consoleLines("info"), []);
 });
 
-test("at a 30000ms interval, a check in the first round is not recorded and does not show in its row", async (t) => {
+test("at a 30000ms interval, a check in the first round does not show in its row", async (t) => {
     CONFIG.updateInterval = 30000;
     const state = new AppState([
         { name: "Answering", url: "https://answering.test" },
@@ -265,10 +239,6 @@ test("at a 30000ms interval, a check in the first round is not recorded and does
     t.mock.timers.tick(1000);
     assert.equal(await settled(round), "still waiting");
     assert.equal(latencyFigure(state, answering), undefined);
-    assert.deepEqual(answering.history, []);
-    assert.equal(answering.status, "pending");
-    assert.deepEqual(consoleLines("error"), []);
-    assert.deepEqual(consoleLines("info"), []);
 });
 
 test("at a 30000ms interval, after the user pauses and resumes during a round, no row reads paused once its last check ends", async (t) => {
@@ -318,6 +288,11 @@ function stateWithOneTarget() {
     return { state, target: state.local[0] };
 }
 
+// What this test wrote to the browser console with console[method].
+function consoleLines(method) {
+    return console[method].mock.calls.map((call) => call.arguments[0]);
+}
+
 test("a check that fails with a network error writes one console line with the target, the time, the error and how long the request took", async (t) => {
     const { state, target } = stateWithOneTarget();
     mockTargets(t, () => 23, target.url);
@@ -496,39 +471,6 @@ test("of the checks interval changes cleared before they were reported, the next
     assert.equal(sent.at(-1).t, 120000);
 });
 
-// panel stands in for the open debug log panel, and for the element in it
-// that holds its lines, whichever the page looks up by id; the lines are
-// kept in order in lines. Drawing the whole panel, as opening it does,
-// replaces every line with a new one.
-test("with the debug log open, writing more lines than it keeps adds each to the panel and leaves the lines already shown as they are", (t) => {
-    const lines = [];
-    const panel = {
-        classList: { contains: () => false },
-        children: lines,
-        get firstElementChild() {
-            return lines[0];
-        },
-        append: (line) => lines.push(line),
-        removeChild: (line) => lines.splice(lines.indexOf(line), 1),
-        replaceChildren: (...newLines) =>
-            lines.splice(0, lines.length, ...newLines),
-    };
-    t.mock.method(globalThis.document, "getElementById", () => panel);
-    const kept = CONFIG.maxLogEntries;
-
-    for (let i = 1; i <= kept; i++) log.info(`line ${i}`);
-    const shown = [...lines];
-    for (let i = kept + 1; i <= kept + 5; i++) log.info(`line ${i}`);
-
-    assert.deepEqual(
-        lines.map((line) => line.textContent.match(/line \d+$/)?.[0]),
-        Array.from({ length: kept }, (_, i) => `line ${i + 6}`),
-    );
-    // The first five lines shown were dropped, and the rest are the same
-    // lines, not drawn again.
-    shown.slice(5).forEach((line, i) => assert.equal(lines[i], line));
-});
-
 // The page shows &lt; &gt; &quot; &amp; and &#39; in a row's markup as
 // < > " & and '.
 test(`a target whose name and URL hold < > " & and ' shows those characters in its row`, () => {
@@ -598,32 +540,6 @@ test("a check that timed out or found its target unreachable has a grey figure a
     assert.equal(latencyHex(null), "#6b7280");
 });
 
-// buildUI draws the page into #app, here a plain object. Each entry in the
-// footer's color legend is a colored dot and the latencies it stands for,
-// with < and > written as &lt; and &gt;. A latency takes the color of the
-// first entry in CONFIG.latencyColors whose limit it is below, so the
-// legend has, for each of those entries in order, a dot of its color (a
-// bg- class where CONFIG.latencyColors has a text- one) and the latencies
-// below its limit, or, for the last, which has no limit, the latencies
-// from the limit before it up. A gray dot for offline comes after them.
-test("the footer's color legend has each entry in CONFIG.latencyColors, with its color and limit, then offline", (t) => {
-    const app = {};
-    t.mock.method(globalThis.document, "getElementById", () => app);
-    buildUI(new AppState([]));
-
-    const legend = [
-        ...app.innerHTML.matchAll(/(bg-\w+-500) [^"]*"><\/span>(\S+)/g),
-    ].map(([, dot, latencies]) => [dot, latencies]);
-    const colors = CONFIG.latencyColors;
-    const expected = colors.map((color, i) => [
-        color.className.replace("text-", "bg-"),
-        color.below === Infinity
-            ? `&gt;=${colors[i - 1].below}ms`
-            : `&lt;${color.below}ms`,
-    ]);
-    assert.deepEqual(legend, [...expected, ["bg-gray-500", "offline"]]);
-});
-
 // A target whose checks, in turn, answered after each of latencies ms, or,
 // for null, found it unreachable.
 function hostAfter(latencies) {
@@ -700,102 +616,6 @@ test("the summary's min, max, median and average latency over the WAN targets' l
     });
 });
 
-// In the next two tests each element of the summary that updateSummary
-// writes into is a plain object, made the first time it is looked up and
-// kept in elements under "#" and its id.
-
-// The interval menu resets each target and counts the rounds from 0 again,
-// then updates the summary, before any check since the change is recorded.
-test("after an interval change, the summary's Reachable slot reads --/-- in white, as at page load", (t) => {
-    t.mock.method(
-        globalThis.document,
-        "getElementById",
-        (id) => (elements[`#${id}`] ??= {}),
-    );
-    const state = new AppState([]);
-    for (const host of state.wan) {
-        host.pushSample(Date.now(), { latency: 30, error: null });
-    }
-    state.tickCount = 5;
-
-    for (const host of state.allHosts) host.reset();
-    state.tickCount = 0;
-    updateSummary(state);
-
-    assert.equal(elements["#summary-reachable"].textContent, "--/--");
-    assert.equal(elements["#summary-reachable"].className, "text-white");
-});
-
-test("once every WAN target's check has failed, the summary's Reachable slot reads 0 of them, in red", (t) => {
-    t.mock.method(
-        globalThis.document,
-        "getElementById",
-        (id) => (elements[`#${id}`] ??= {}),
-    );
-    const state = new AppState([]);
-    for (const host of state.wan) {
-        host.pushSample(Date.now(), { latency: null, error: "timeout" });
-    }
-
-    updateSummary(state);
-
-    assert.equal(
-        elements["#summary-reachable"].textContent,
-        `0/${state.wan.length}`,
-    );
-    assert.equal(elements["#summary-reachable"].className, "text-red-400");
-});
-
-// In the next two tests each of the header's clocks is a plain object, made
-// the first time updateClocks looks it up and kept in elements under "#" and
-// its id.
-
-// The mocked clock reads 1970-01-01T00:00:00.000Z.
-test("the header's clocks show the local time with its time zone's name, and the UTC time", (t) => {
-    t.mock.method(
-        globalThis.document,
-        "getElementById",
-        (id) => (elements[`#${id}`] ??= {}),
-    );
-    t.mock.timers.enable({ apis: ["Date"] });
-
-    updateClocks();
-
-    assert.match(
-        elements["#clock-local"].textContent,
-        /^Local: \d{4}-\d\d-\d\d \d\d:\d\d:\d\d \S/,
-    );
-    assert.equal(
-        elements["#clock-utc"].textContent,
-        "UTC: 1970-01-01 00:00:00 UTC",
-    );
-});
-
-// Here Intl.DateTimeFormat is as in Chrome before 95, Firefox before 91 or
-// Safari before 15.4: it throws a RangeError when asked for the time zone's
-// "shortGeneric" name.
-test("in a browser that cannot name the time zone, updating the clocks throws nothing and leaves them blank", (t) => {
-    t.mock.method(
-        globalThis.document,
-        "getElementById",
-        (id) => (elements[`#${id}`] ??= {}),
-    );
-    const DateTimeFormat = Intl.DateTimeFormat;
-    t.mock.method(Intl, "DateTimeFormat", function (locales, options) {
-        if (options?.timeZoneName === "shortGeneric") {
-            throw new RangeError(
-                "Value shortGeneric out of range for Intl.DateTimeFormat options property timeZoneName",
-            );
-        }
-        return new DateTimeFormat(locales, options);
-    });
-
-    updateClocks();
-
-    assert.equal(elements["#clock-local"].textContent, "");
-    assert.equal(elements["#clock-utc"].textContent, "");
-});
-
 // An app state in which, of the WAN targets, the first timedOut timed out,
 // the next unreachable were found unreachable, the next answered answered
 // after latency ms, and the rest have not been checked yet.

web/src/main.js

@@ -144,15 +144,13 @@ const WAN_HOSTS = [
 
 const debugLog = [];
 
-export const log = (() => {
+const log = (() => {
     function append(level, message) {
-        const entry = { timestamp: new Date(), level, message };
+        debugLog.push({ timestamp: new Date(), level, message });
-        debugLog.push(entry);
         if (debugLog.length > CONFIG.maxLogEntries)
             debugLog.splice(0, debugLog.length - CONFIG.maxLogEntries);
         const panel = document.getElementById("debug-panel");
-        if (panel && !panel.classList.contains("hidden"))
+        if (panel && !panel.classList.contains("hidden")) renderDebugLog();
-            appendDebugLogLine(entry);
     }
     return {
         error: (msg) => append("error", msg),
@@ -829,7 +827,7 @@ function wanRowsHTML(wanHosts) {
     return rows.join("");
 }
 
-export function buildUI(state) {
+function buildUI(state) {
     const app = document.getElementById("app");
     app.innerHTML = `
     <div class="mx-auto px-[5%] py-8">
@@ -911,7 +909,7 @@ export function buildUI(state) {
           <span class="inline-block w-3 h-3 rounded-full bg-lime-500 mr-1 ml-3 align-middle"></span>&lt;100ms
           <span class="inline-block w-3 h-3 rounded-full bg-yellow-500 mr-1 ml-3 align-middle"></span>&lt;200ms
           <span class="inline-block w-3 h-3 rounded-full bg-orange-500 mr-1 ml-3 align-middle"></span>&lt;500ms
-          <span class="inline-block w-3 h-3 rounded-full bg-red-500 mr-1 ml-3 align-middle"></span>&gt;=500ms
+          <span class="inline-block w-3 h-3 rounded-full bg-red-500 mr-1 ml-3 align-middle"></span>&gt;500ms
           <span class="inline-block w-3 h-3 rounded-full bg-gray-500 mr-1 ml-3 align-middle"></span>offline
         </p>
         <p class="mt-2"><a href="https://git.eeqj.de/sneak/netwatch/commit/${__COMMIT_FULL__}" target="_blank" rel="noopener" class="text-gray-600 hover:text-gray-400">${__COMMIT_HASH__}</a></p>
@@ -995,7 +993,7 @@ function updateHostRow(host, index) {
     SparklineRenderer.draw(canvas, host.history);
 }
 
-export function updateSummary(state) {
+function updateSummary(state) {
     const stats = state.wanStats();
     const hstats = state.wanHistoryStats();
 
@@ -1014,20 +1012,13 @@ export function updateSummary(state) {
     const hmaxUnitEl = document.getElementById("summary-hmax-unit");
     if (!reachableEl) return;
 
-    // Before any WAN host's check is recorded, as after an interval change,
+    reachableEl.textContent = `${stats.reachable}/${stats.total}`;
-    // no host has answered or failed, so the slot reads as at page load.
+    reachableEl.className =
-    if (state.wan.every((h) => h.status === "pending")) {
+        stats.reachable === stats.total
-        reachableEl.textContent = "--/--";
+            ? "text-green-400"
-        reachableEl.className = "text-white";
+            : stats.reachable === 0
-    } else {
+              ? "text-red-400"
-        reachableEl.textContent = `${stats.reachable}/${stats.total}`;
+              : "text-yellow-400";
-        reachableEl.className =
-            stats.reachable === stats.total
-                ? "text-green-400"
-                : stats.reachable === 0
-                  ? "text-red-400"
-                  : "text-yellow-400";
-    }
 
     if (stats.min !== null) {
         minEl.textContent = `${stats.min}`;
@@ -1114,37 +1105,11 @@ function updateHealthBox(state) {
     else if (health === "healthy") log.notice(`Health: ${labels[health]}`);
 }
 
-// Writes the local time, with its time zone's name, and the UTC time into
-// the header's clocks. The clocks only decorate the page: in a browser
-// whose Intl.DateTimeFormat rejects the "shortGeneric" time zone name
-// (Chrome before 95, Firefox before 91, Safari before 15.4) they are left
-// blank.
-export function updateClocks() {
-    let local = "";
-    let utc = "";
-    try {
-        const now = new Date();
-        const zone = new Intl.DateTimeFormat("en-US", {
-            timeZoneName: "shortGeneric",
-        })
-            .formatToParts(now)
-            .find((p) => p.type === "timeZoneName").value;
-        const pad = (n) => String(n).padStart(2, "0");
-        local = `Local: ${now.toLocaleString("sv-SE", { hour12: false })} ${zone}`;
-        utc =
-            `UTC: ${now.getUTCFullYear()}-${pad(now.getUTCMonth() + 1)}-${pad(now.getUTCDate())} ` +
-            `${pad(now.getUTCHours())}:${pad(now.getUTCMinutes())}:${pad(now.getUTCSeconds())} UTC`;
-    } catch {
-        // Both clocks are left blank.
-    }
-    document.getElementById("clock-local").textContent = local;
-    document.getElementById("clock-utc").textContent = utc;
-}
-
 // --- Debug Log Renderer ------------------------------------------------------
 
-// One line of the debug log panel, its message set as text.
+function renderDebugLog() {
-function debugLogLine(entry) {
+    const el = document.getElementById("debug-log");
+    if (!el) return;
     const levelColors = {
         error: "text-red-400",
         warning: "text-orange-400",
@@ -1152,43 +1117,19 @@ function debugLogLine(entry) {
         info: "text-gray-300",
         debug: "text-gray-500",
     };
-    const ts = formatUTCTimestamp(entry.timestamp);
+    el.replaceChildren(
-    const lvl = entry.level.toUpperCase().padEnd(7);
+        ...debugLog.map((entry) => {
-    const line = document.createElement("div");
+            const ts = formatUTCTimestamp(entry.timestamp);
-    line.className = levelColors[entry.level] || "text-gray-400";
+            const lvl = entry.level.toUpperCase().padEnd(7);
-    line.textContent = `${ts} ${lvl} ${entry.message}`;
+            const line = document.createElement("div");
-    return line;
+            line.className = levelColors[entry.level] || "text-gray-400";
-}
+            line.textContent = `${ts} ${lvl} ${entry.message}`;
-
+            return line;
-// Draws every line of the debug log into the panel, when it is opened.
+        }),
-function renderDebugLog() {
+    );
-    const el = document.getElementById("debug-log");
-    if (!el) return;
-    el.replaceChildren(...debugLog.map((entry) => debugLogLine(entry)));
     el.scrollTop = el.scrollHeight;
 }
 
-// The request that scrolls the open panel to its newest line in the next
-// frame. One waits at most, also in a hidden tab, where frames do not run.
-let debugLogScrollFrame = 0;
-
-// Adds entry to the open panel as its last line, and drops the first line
-// once the panel holds more than maxLogEntries. A check that ends while the
-// page is busy is timed only when the page is done, so the lines already
-// shown are left as they are, and the panel is scrolled once a frame
-// rather than once a line: scrolling it lays out all of its lines again.
-function appendDebugLogLine(entry) {
-    const el = document.getElementById("debug-log");
-    if (!el) return;
-    el.append(debugLogLine(entry));
-    if (el.children.length > CONFIG.maxLogEntries)
-        el.removeChild(el.firstElementChild);
-    cancelAnimationFrame(debugLogScrollFrame);
-    debugLogScrollFrame = requestAnimationFrame(() => {
-        el.scrollTop = el.scrollHeight;
-    });
-}
-
 // --- Sorting -----------------------------------------------------------------
 
 // Sort WAN hosts: pinned hosts first (alphabetically), then unpinned hosts
@@ -1536,6 +1477,24 @@ async function init() {
         sortAndRebuildWAN(state);
     });
 
+    function updateClocks() {
+        const now = new Date();
+        const pad = (n) => String(n).padStart(2, "0");
+        const utc =
+            `${now.getUTCFullYear()}-${pad(now.getUTCMonth() + 1)}-${pad(now.getUTCDate())} ` +
+            `${pad(now.getUTCHours())}:${pad(now.getUTCMinutes())}:${pad(now.getUTCSeconds())} UTC`;
+        const local =
+            now.toLocaleString("sv-SE", { hour12: false }) +
+            " " +
+            new Intl.DateTimeFormat("en-US", { timeZoneName: "shortGeneric" })
+                .formatToParts(now)
+                .find((p) => p.type === "timeZoneName").value;
+        document.getElementById("clock-local").textContent = "Local: " + local;
+        document.getElementById("clock-utc").textContent = "UTC: " + utc;
+    }
+    updateClocks();
+    setInterval(updateClocks, 1000);
+
     // Rounds never overlap: a round first gives up the last round's checks
     // if they are still waiting, and the last round then records nothing
     // more. At a steady interval they never are, as they time out at 80% of
@@ -1615,11 +1574,6 @@ async function init() {
 
     window.addEventListener("resize", () => handleResize(state));
     setTimeout(() => handleResize(state), CONFIG.resizeDelay);
-
-    // The clocks start last, after the rounds: they only decorate the page,
-    // so nothing in them may stop the monitor from probing.
-    updateClocks();
-    setInterval(updateClocks, 1000);
 }
 
 // Bootstrap only when loaded as the page: a real DOM containing the #app