Serve Prometheus metrics at /metrics behind basic auth (closes #94)

With METRICS_USERNAME and METRICS_PASSWORD both set, the backend
records request metrics through go-http-metrics in a registry of its
own, with Go's runtime and process metrics, and serves them at
GET /metrics behind basic auth with those credentials; nginx passes
/metrics to it. With neither set there is no such route; one alone
stops the start with an error naming both.

Only requests that reach the health check or POST /api/v1/reports are
recorded, not every request as the conventions show: the labels are
path and method, which clients can make up without end. So
POST /api/v1/reports is registered by its full path, not inside a
route group.

Deviation: go get and go mod tidy ran directly; no entrypoint adds a Go
dependency yet (#45).

Model: opus-5-5

.prettierignore

@@ -1,7 +1,6 @@
+backend/
 dist/
 node_modules/
 tmp/
 yarn.lock
 .claude/
-# The org standard file, copied verbatim; backend/script/lint checks its sha256.
-backend/.golangci.yml

Makefile

@@ -1,5 +1,5 @@
-.PHONY: bootstrap setup dev build test lint fmt fmt-check check \
+.PHONY: bootstrap setup dev test lint fmt fmt-check check frontend-check \
-	add-dependency tidy frontend-check frontend-viewport-test docker hooks
+	frontend-viewport-test docker hooks
 
 # Standard targets are thin shims; the implementations live in script/
 # per the scripts-to-rule-them-all pattern (see the Entrypoints section
@@ -13,11 +13,7 @@ setup:
 	@script/setup
 
 dev:
-	@script/dev
+	yarn dev
-
-# The frontend only; backend/Makefile's build target builds the Go server.
-build:
-	@script/build
 
 test:
 	@script/test
@@ -34,14 +30,6 @@ fmt-check:
 check:
 	@script/check
 
-# make add-dependency PACKAGE=<name>@<version>. PACKAGE reaches the
-# script through the environment, so the shell never reads it as code.
-add-dependency:
-	@script/add-dependency "$$PACKAGE"
-
-tidy:
-	@script/tidy
-
 # The frontend tests and format check, for Dockerfile's frontend stage,
 # which has neither Go nor Docker. Use check everywhere else.
 frontend-check:

README.md

@@ -1,33 +1,30 @@
 NetWatch is an MIT-licensed JavaScript single-page application by
 [@sneak](https://sneak.berlin) that provides real-time network latency
 monitoring to common internet hosts, displayed with color-coded figures and
-sparkline graphs, served from a static bucket or from its Docker image, where a
+sparkline graphs, served from a static bucket or Docker container.
-small Go backend stores the measurements the page reports.
 
 ## Getting Started
 
 ```bash
-# Install the dependencies and the git pre-commit hook
+# Install dependencies
-make setup
+yarn install
 
-# Run the page on the Vite dev server
+# Development server
-make dev
+yarn dev
 
-# Run the tests, both linters and the format check
+# Production build
-make check
+yarn build
 
-# Build the page into dist/
+# Preview production build
-make build
+yarn preview
 
-# Build the image and run it
+# Docker
-make docker
+docker build -t netwatch .
 docker run -p 8080:8080 netwatch
 ```
 
-`make check` and `make docker` need Docker. `make dev` passes `/api` to
+`yarn dev` proxies `/api` to `http://127.0.0.1:8080`, so a locally running
-`http://127.0.0.1:8080`, where `make run` in `backend/` starts `netwatch-server`
+`netwatch-server` (see `backend/`) receives the reports the page posts.
-with its defaults, so the reports the page posts are stored in
-`backend/data/reports`.
 
 ## Entrypoints
 
@@ -49,10 +46,6 @@ halves, so the root `make check` fails if either one is broken. We provide:
   both linters 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
-  running `netwatch-server`
-- `script/build` — build the frontend for production into `dist/`;
-  `backend/script/build` builds the Go server
 - `script/projectname` — print the project name (used for the Docker image tag)
 - `script/test` — run `script/frontend-test`, then `backend/script/test`, the
   backend's Go tests with the race detector and coverage
@@ -61,13 +54,6 @@ halves, so the root `make check` fails if either one is broken. We provide:
 - `script/fmt` — format all files (writes): prettier, then gofmt over `backend/`
 - `script/fmt-check` — check formatting (read-only): prettier, then gofmt
 - `script/check` — run test, lint, and fmt-check
-- `script/add-dependency` — add a frontend package, or move one to another
-  version: `make add-dependency PACKAGE=<name>@<version>` runs `yarn add --dev`,
-  which changes `package.json` and `yarn.lock` together, then
-  `yarn install --frozen-lockfile`
-- `script/tidy` — run `go mod tidy` in `backend/`: to add a Go module, import it
-  and run `make tidy`; to move one to another version, edit its `require` line
-  in `backend/go.mod`, then run `make tidy`
 - `script/frontend-test` — run the unit tests in `test/unit/` 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.
@@ -75,8 +61,7 @@ halves, so the root `make check` fails if either one is broken. We provide:
 - `script/frontend-lint` — run eslint with the rules in `eslint.config.js`; it
   runs inside the `frontend-lint` stage of `Dockerfile`, which `make lint`
   builds
-- `script/frontend-fmt` — format everything prettier understands (writes), the
+- `script/frontend-fmt` — format everything prettier understands (writes)
-  markdown in `backend/` included
 - `script/frontend-fmt-check` — check prettier formatting (read-only)
 - `script/frontend-check` — run `script/frontend-test` and
   `script/frontend-fmt-check`, for the frontend stage of `Dockerfile`, which has
@@ -97,30 +82,25 @@ halves, so the root `make check` fails if either one is broken. We provide:
 The narrow-viewport layout lives in the `max-width: 768px` media block in
 `src/styles.css`. It is verified automatically by `make frontend-viewport-test`,
 which drives a digest-pinned headless Chrome against the built `dist/` and
-asserts on computed layout at widths derived from that CSS — on every breakpoint
+asserts on computed layout at widths derived from that CSS — one pixel either
-it declares and one pixel either side of it, plus a 320px floor, a desktop
+side of every breakpoint it declares, plus a 320px floor, a desktop baseline and
-baseline and two landscape sizes. See
+two landscape sizes. See [test/viewport/README.md](test/viewport/README.md) for
-[test/viewport/README.md](test/viewport/README.md) for what it covers and what
+what it covers and what it genuinely cannot.
-it genuinely cannot.
 
 ## Rationale
 
 When debugging network issues, it's useful to have a persistent at-a-glance view
 of latency and reachability to multiple well-known internet endpoints. NetWatch
-provides this as a single page that does all its measuring in the browser, so it
+provides this as a zero-dependency SPA that can be deployed anywhere static
-can be served from anywhere static files are served. The backend in its Docker
+files are served, with no backend required.
-image only stores the measurements the page reports; without it, the page works
-the same and nothing is stored.
 
 ## Design
 
-The page is built with Vite and Tailwind CSS v4. Its code is all in
+The application is a single-page app built with Vite and Tailwind CSS v4. All
-`src/main.js`, with a class-based architecture:
+code lives in `src/main.js` with a class-based architecture:
 
-- **`CONFIG`**: Configuration object (update interval, timeouts, axis ticks,
+- **`CONFIG`**: Frozen configuration object (update interval, timeouts, axis
-  etc.). The interval menu sets `updateInterval`, the one value the page writes
+  ticks, etc.)
-  into `CONFIG`; the timeouts, the time the history spans and the x-axis ticks
-  are computed from it
 - **`HostState`**: Per-host state management — history buffer, latency tracking,
   status transitions
 - **`AppState`**: Top-level state container — WAN hosts, local hosts, pause
@@ -131,10 +111,10 @@ The page is built with Vite and Tailwind CSS v4. Its code is all in
   `updateSummary()` / `updateHealthBox()` handle incremental updates
 - **`tick()`**: Main loop — measures all hosts in parallel, pushing each host's
   sample and redrawing its row as soon as its check ends, then redraws every
-  row, the summary and the health box once the last check ends. The first round,
+  row, the summary and the health box once the last check ends. The rows are
-  after loading or an interval change, is discarded. The rows are sorted when
+  sorted then too, after the first round that is not discarded and every tenth
-  the last check ends in round 2, the first one kept, and in rounds 11, 21, 31
+  round after that. When paused, pushes blank markers (no probes, no false
-  and so on. When paused, pushes blank markers (no probes, no false outage)
+  outage)
 - **`Reporter`**: Posts collected samples to the backend
 
 ### Reporting
@@ -148,35 +128,12 @@ delivered report, and while paused nothing is sent. Delivery failure is quiet
 one debug-log line per outage, retried at the next interval, never blocking
 probing. The report-building step is a pure function of host state.
 
-### Backend
-
-`netwatch-server`, in `backend/`, is a small Go HTTP server that stores the
-reports the page posts. It keeps them in memory and writes them to `DATA_DIR` as
-zstd-compressed files of JSON lines: every minute, whenever 10 MiB are waiting,
-and when it stops. Its routes:
-
-- `POST /api/v1/reports` — takes a report, without credentials; each client
-  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
-- `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
-
-In the image, the `builder` stage of `Dockerfile` tests it and builds it with
-`backend/script/build`, and `bin/entrypoint.sh` runs it as user `netwatch` on
-`127.0.0.1:8081`, behind nginx. Outside the image, `make run` in `backend/`
-builds it and runs it on port 8080. Its settings, report storage and limits are
-in [backend/README.md](backend/README.md).
-
 ### Monitoring targets
 
-- **26 WAN hosts**: datavi.be (pinned at start), Anthropic API, OpenAI API, AWS
+- **22 WAN hosts**: datavi.be, Anthropic API, OpenAI API, AWS Console, GCP
-  Console, Google Cloud Console, Microsoft Azure, Cloudflare, Fastly CDN,
+  Console, Azure, Cloudflare, Fastly, Akamai, GitHub, B2, 7 S3 regional
-  Akamai, Google, GitHub, B2, 8 S3 regional endpoints (Cape Town, London,
+  endpoints (Cape Town, London, Bahrain, Tokyo, Sydney, Oregon, São Paulo), 4
-  Bahrain, Tokyo, Singapore, Sydney, Oregon, São Paulo) and 6 Hetzner speed test
+  GCS locational endpoints (Iowa, Belgium, Singapore, Sydney)
-  servers (Nuremberg, Falkenstein, Helsinki, Ashburn, Hillsboro, Singapore)
 - **Local CPE**: Cable modem at 192.168.100.1 (always monitored)
 - **Local Gateway**: Auto-detected on startup by probing common default gateway
   addresses (192.168.1.1, 192.168.0.1, 192.168.8.1, 10.0.0.1); first responder
@@ -188,17 +145,15 @@ Local hosts are tracked separately from WAN stats.
 
 ### Latency measurement
 
-GET requests with `mode: 'no-cors'`, `cache: 'no-store'` and a cache-busting
+HEAD requests with `mode: 'no-cors'` and `cache: 'no-store'`, timed with
-query parameter, timed with `performance.now()`. Each check times out after 80%
+`performance.now()`. Each check times out after 80% of the refresh interval (24
-of the refresh interval (24 seconds at 30 seconds) and is then recorded as a
+seconds at 30 seconds) and is then recorded as a timeout, so a round's checks
-timeout, so a round's checks have all finished before the next round is due.
+have all finished before the next round is due. When no WAN host answers, a
-When no WAN host answers, a recovery probe checks 4 WAN hosts, picked at random
+recovery probe checks 4 random WAN hosts every half second, giving up the checks
-when it starts, every half second, giving up the checks it started half a second
+it started half a second before. As soon as one answers, a new round starts at
-before. As soon as one answers, a new round starts at once, as it does after an
+once, as it does after an interval change. A round started early gives up the
-interval change. A round started early gives up the last round's checks if they
+last round's checks if they are still waiting, and that round records nothing
-are still waiting, and that round records nothing more, so rounds never overlap.
+more, so rounds never overlap. IPv4 only.
-The browser chooses between IPv4 and IPv6 for each target, as for any request;
-the local targets are IPv4 addresses.
 
 ### Color coding
 
@@ -223,42 +178,25 @@ dist/
 
 ## Features
 
-- A round of checks every 3 seconds by default; the interval menu sets 1, 2, 3,
+- Real-time monitoring with 2s update interval and 300s history sparklines
-  5, 10, 15, 30 or 60 seconds and clears the history
+- Health indicator: green (HEALTHY) or red (DEGRADED) based on WAN reachability
-- Sparklines of each target's last 100 rounds: 300 seconds at 3 seconds
+- Summary stats: reachable count, min/max/avg latency across WAN hosts only
-- The first round after loading or an interval change is discarded, as DNS and
+- Fixed chart axes: Y-axis 0–1000ms, X-axis 0–300s
-  TLS setup inflate its latencies
-- Health indicator from the WAN hosts' latest results: OFFLINE (red) when more
-  than 10 fail and at most 4 answer, otherwise DEGRADED (orange) when more than
-  4 fail, otherwise SLOW (yellow) when more than 3 take over 1000ms, otherwise
-  HEALTHY (green)
-- Summary stats across WAN hosts only: how many answered, the min, median,
-  average and max of their latest latencies, the min and max over the whole
-  history, and the number of rounds run (`Checks`)
-- Fixed chart axes: Y-axis 0–1000ms, higher latencies drawn at the top; X-axis
-  the time the history spans
 - Color-coded latency figures and sparkline line segments
-- WAN host rows sorted by latest latency, unreachable last; pinned rows stay on
-  top, in name order
 - Play/pause: pause stops probes but history keeps scrolling (blank gaps, no
   false outage)
-- Debug log panel, behind a checkbox in the footer, with five levels (error,
-  warning, notice, info, debug) and the last 1000 lines
-- Local and UTC clocks
 - Clickable service URLs
-- A footer link to the commit the page was built from
 - Canvas-based sparkline rendering with devicePixelRatio scaling
 - Zero runtime dependencies: all resources bundled into build artifacts
 
 ## Deployment
 
-`make build` writes the page to `dist/`, which any static file host (S3, GCS,
+After running `yarn build`, deploy the contents of the `dist/` directory to any
-Cloudflare Pages, Vercel, Netlify, GitHub Pages) can serve; with no backend
+static file host (S3, GCS, Cloudflare Pages, Vercel, Netlify, GitHub Pages) or
-there, its reports fail quietly and nothing is stored. Or run the Docker image
+use the Docker image behind a reverse proxy.
-behind a reverse proxy.
 
-The Docker image, built from `Dockerfile` by `make docker`, is the whole service
+The Docker image, built from `Dockerfile`, is the whole service in one
-in one container: nginx serves the built frontend and passes `/api/`,
+container: nginx serves the built frontend and passes `/api/`,
 `/.well-known/healthcheck` and `/metrics` to the Go backend, `netwatch-server`,
 which listens only inside the container, on `127.0.0.1:8081`. The image:
 
@@ -312,12 +250,8 @@ What the [upaas](https://git.eeqj.de/sneak/upaas) app for netwatch needs:
       the backend records Prometheus metrics of its requests and serves them at
       `/metrics` on the container port, to requests with this user name and
       password as their basic auth credentials. With neither set, there are no
-      metrics and `/metrics` is not found. One set without the other, or a user
+      metrics and `/metrics` is not found. One set without the other stops the
-      name containing `:`, stops the container
+      container
-    - `SENTRY_DSN`, default empty: set to a Sentry project's DSN, the backend
-      sends its errors to that Sentry project: each request whose handling
-      crashes, which still gets a 500 response. A value Sentry does not accept
-      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. upaas reads the container's health 60
@@ -331,19 +265,19 @@ properties.
 
 ## Limitations
 
-- **CORS**: The checks are cross-origin requests in `no-cors` mode, so the page
+- **CORS**: Some hosts may block cross-origin HEAD requests. The app uses
-  cannot read the answer, only time it: any answer counts as reachable, an error
+  `no-cors` mode which allows the request but provides opaque responses. Latency
-  page included.
+  is still measurable based on request timing.
-- **Local targets**: The cable modem at 192.168.100.1 and the detected gateway
+- **Local gateway**: The 192.168.100.1 endpoint requires the host to be
-  answer only on a network that has them, and only when NetWatch is served from
+  accessible from your network.
-  localhost or a private address (see Monitoring targets).
 - **Network conditions**: Measurements reflect browser-to-endpoint latency,
   which includes your local network, ISP, and internet routing.
 
 ## TODO
 
-The to-do list is [TODO.md](TODO.md): where the work stands, the next step, the
+- Add configurable host list (environment variable or config file)
-open work, and what has been done.
+- Add latency history export (CSV/JSON)
+- Add notification/alert when status changes to DEGRADED
 
 ## License
 

TODO.md

@@ -1,108 +1,40 @@
 # Workflow
 
-- branch from `next`
+- branch (from `main`)
 - do the work in Next Step
 - move Next Step to the top of Completed Steps
 - move the top item of Future Steps into Next Step
 - commit (`TODO.md` changes in the same commit as the work)
-- push the branch and open a PR against `next`
+- merge to `main` if the branch is not protected, otherwise open a PR
+- push
 
 # Status
 
-pre-1.0. No git tags. `main` is the stable branch and `next` the development
+pre-1.0. No git tags. `feat/reportbuf-storage` is merged; the backend, the CI
-branch, which every PR targets. The frontend and the Go backend ship as one
+workflow, and the backend repo standard files are all on `main`. Frontend and
-Docker image, and the Gitea workflow `.gitea/workflows/check.yml` runs
+backend are both functional. Working toward the 1.0.0 milestone by closing the
-`script/cibuild` on every push. Working toward 1.0.0.
+remaining repo-compliance issues on the tracker.
 
 # Next Step
 
-Decide whether the repo moves to the layout `REPO_POLICIES.md` gives, with
+Confirm the `.gitea/workflows/check.yml` run is green (main always green
-`backend/` no longer repeating files from the root
+policy). The workflow file is already on `main`; what is unverified is that its
-([#30](https://git.eeqj.de/sneak/netwatch/issues/30)).
+latest run passes.
 
 # Completed Steps
 
-- 2026-10-04: the page's footer no longer says "IPv4 only"
-  ([#111](https://git.eeqj.de/sneak/netwatch/issues/111)): each check is a
-  `fetch`, the browser picks IPv4 or IPv6 for each WAN host, and the local
-  targets are IPv4 addresses. The rest of the footer is unchanged
-- 2026-10-04: `README.md`, `TODO.md` and `test/viewport/README.md` say what the
-  tree does (issue #24). The README's Getting Started leads with `make` targets;
-  a new Backend section says what `netwatch-server` stores, its routes and how
-  the image builds and runs it, and points to `backend/README.md` for its
-  settings; the checks are GET requests; the 26 WAN hosts, the four health
-  states, the summary's figures and the features the list lacked are described
-  as the page has them; and its TODO section points here, as does the one in
-  `backend/README.md`, whose open items moved to Future Steps. This file's
-  Workflow branches from `next` and opens the PR against `next`, Status says
-  where the repo stands, and Next Step and Future Steps hold only open work,
-  linked to its issue where one exists. The viewport harness README names Node's
-  test runner, not `vitest`
-- 2026-10-04: in `src/main.js` (issue #102), a target's min, max, median and
-  average latency come from one list of its answers, through the same function
-  the summary's figures use, so the median is written once. The latency color
-  limits are one table in `CONFIG`, read by both the figure's and the
-  sparkline's color. The health thresholds, the debug log's length, the gateway
-  check's timeout, the recovery probe's number of hosts and interval, how often
-  the rows are sorted and the delay before the first sparkline resize are
-  `CONFIG` entries too. A unit test checks the summary's figures. Nothing the
-  page does or shows changed; the footer's color legend still writes the limits
-  out as text
-- 2026-10-04: password guesses at `/metrics` are rate limited (issue #104): each
-  client address, resolved through `TRUSTED_PROXIES` as for reports, may make 60
-  requests to `/metrics` a minute, counted by `go-chi/httprate` apart from its
-  reports; past that it gets 429 and its basic auth credentials are not checked.
-  The limit is a constant in `backend/internal/server/routes.go`. A test uses up
-  one client's allowance on wrong passwords, gets 429 with the right one, and
-  checks that another client behind the same nginx still gets in
-- 2026-10-04: the backend reports errors to Sentry (issue #95). With
-  `SENTRY_DSN` set, it sets up `sentry-go` with the release `netwatch-server-`
-  and its version, reports each panic in a handler through `sentryhttp`, the
-  last of the middleware every request goes through, which panics again so the
-  request still gets the 500 from the panic recovery, and waits up to 2 seconds
-  on shutdown for Sentry to finish sending. A DSN Sentry refuses stops the start
-  with an error naming `SENTRY_DSN`. With it empty, Sentry is not set up and
-  nothing is sent to it
-- 2026-10-04: a target's name and URL and a debug log message show as the
-  characters they are and are never read as HTML (issue #29): a host row escapes
-  the name and URL it writes into its markup, and the debug log sets each line
-  as text. A unit test checks a target whose name and URL hold `<`, `>`, `"`,
-  `&` and `'`. `README.md` no longer calls `CONFIG` frozen: the interval menu
-  sets its `updateInterval`, and the values computed from it follow. `AppState`
-  declares the recovery probe's two properties, the sparkline axis functions
-  lose the parameters they did not use, and the comment on a target's history
-  names both kinds of entry it holds. Nothing the page does changed
-- 2026-10-04: a dependency can be added without running yarn or go by hand
-  (issue #45): `make add-dependency PACKAGE=<name>@<version>` shims to the new
-  `script/add-dependency`, which runs `yarn add --dev`, so `package.json` and
-  `yarn.lock` change together, then `yarn install --frozen-lockfile`; the same
-  command moves a package to another version. `make tidy` shims to the new
-  `script/tidy`, which runs `go mod tidy` in `backend/`: a Go module is added by
-  importing it, or moved by editing its `require` line, then `make tidy`.
-  `script/bootstrap` still installs with `--frozen-lockfile`
 - 2026-10-04: the backend serves Prometheus metrics (issue #94). With
   `METRICS_USERNAME` and `METRICS_PASSWORD` both set, it records request
   duration and response size through `go-http-metrics` and serves them, with
   Go's runtime and process metrics, at `GET /metrics` behind basic auth with
   those credentials; nginx passes `/metrics` to it as it does `/api/`. With
   neither set there are no metrics and `/metrics` is 404; one without the other
-  stops the start with an error naming both, and so does a `METRICS_USERNAME`
+  stops the start with an error naming both. Only requests that reach the health
-  containing `:`, with an error naming it. Only requests that reach the health
   check or `POST /api/v1/reports` are recorded, not `/metrics` itself and not
   every request as `GO_HTTP_SERVER_CONVENTIONS.md` shows, because the labels are
   the request's path and method, which clients can make up without end. For
   that, `POST /api/v1/reports` is now registered by its full path instead of
   inside a `/api/v1` route group; it answers as before
-- 2026-10-04: `script/` and `Makefile` follow the org models (issue #28):
-  `make dev` shims to the new `script/dev`, the Vite dev server, and the new
-  `make build` to `script/build`, the frontend production build.
-  `.prettierignore` no longer leaves out `backend/`, so `make fmt` and
-  `make fmt-check` cover `backend/README.md`; it leaves out
-  `backend/.golangci.yml` by name, the org standard file whose sha256
-  `backend/script/lint` checks. `script/install-precommit` and the date on
-  `script/bootstrap`'s pins are the org model again; `script/bootstrap`,
-  `script/fmt` and `script/fmt-check` each say in a comment why they differ from
-  it
 - 2026-10-04: a frontend build on Node 26 or newer, such as `make test` on a
   host with Node 26, no longer prints Node's warning that `module.register()` is
   deprecated (issue #32); the build in `Dockerfile` runs on Node 22, which never
@@ -389,14 +321,12 @@ Decide whether the repo moves to the layout `REPO_POLICIES.md` gives, with
 
 # Future Steps
 
-- Run `make frontend-viewport-test` in CI as its own step; it is not part of
+- Wire `script/frontend-viewport-test` into CI as its own step (deliberately not
-  `make check`, as it needs Docker and takes minutes
+  part of `make check` today; the decision has real CI-runtime cost and is
-- A backend test that posts a report to `POST /api/v1/reports` and checks the
+  tracked separately)
-  compressed file it is written to
+- Compliance top-up as one small commit: add .editorconfig and add the hooks
-- A backend route that decompresses the stored reports and answers queries on
+  target to the Makefile
-  them
+- After merge, confirm .gitea/workflows/check.yml is on main and CI is green
-- Prometheus metrics for the backend's in-memory buffer: its size, the number of
+  (main always green policy)
-  flushes and the number of reports
+- Decide what to do with untracked resume.sh: commit it, gitignore it, or delete
-- A configurable host list (an environment variable or a config file)
+  it
-- Export of the latency history (CSV or JSON)
-- A notification when the health status changes to DEGRADED

backend/README.md

@@ -32,16 +32,17 @@ pattern as the repo root: the targets in `backend/Makefile` are thin shims over
 `test`, `fmt` and `fmt-check`:
 
 - `script/build` — compile the static `netwatch-server` binary with its version
-  stamped in. The version is `VERSION` from the environment; when that is unset
+  stamped in. The version is `VERSION` from the environment;
-  or empty, it falls back to `git describe` inside a git checkout, then to `dev`
+  when that is unset or empty, it falls back to `git describe` inside a git
+  checkout, then to `dev`
 - `script/test` — run the Go tests with the race detector and coverage. Go's
   `-timeout 30s` bounds the tests, not their compile. If they fail, they run
   again with `-v` for the details, and the script fails. The race detector needs
   a C compiler
 - `script/lint` — check `.golangci.yml` against its pinned sha256, then run
-  golangci-lint. It runs inside the golangci-lint image of the lint stage of the
+  golangci-lint. It runs inside the golangci-lint image of the lint stage of
-  root `Dockerfile`; from a checkout, run `make lint` at the repo root, which
+  the root `Dockerfile`; from a checkout, run `make lint` at the repo root,
-  builds that stage
+  which builds that stage
 - `script/fmt` — format the Go sources (writes)
 - `script/fmt-check` — check Go formatting (read-only)
 - `script/run` — build and run the server locally
@@ -60,9 +61,8 @@ flushes them to compressed files on disk for later analysis.
 
 ## Design
 
-The server is structured as an `fx`-wired Go application under
+The server is structured as an `fx`-wired Go application under `cmd/netwatch-server/`.
-`cmd/netwatch-server/`. Internal packages in `internal/` follow standard Go
+Internal packages in `internal/` follow standard Go project layout:
-project layout:
 
 - **`config`**: Loads configuration from environment variables and config files
   via Viper.
@@ -90,14 +90,12 @@ project layout:
 | `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
+`TRUSTED_PROXIES` defaults to `127.0.0.1/32,::1/128,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16`.
-`127.0.0.1/32,::1/128,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16`. The loopback
+The loopback entries cover a reverse proxy on the same host. A request whose
-entries cover a reverse proxy on the same host. A request whose direct peer is
+direct peer is outside this set has its forwarded headers ignored, and the
-outside this set has its forwarded headers ignored, and the direct peer is
+direct peer is logged and rate-limited instead. The container image does not use
-logged and rate-limited instead. The container image does not use this default;
+this default; see [Container image](#container-image).
-see [Container image](#container-image).
 
 A variable set to a value the server cannot use, such as `PORT=abc`,
 `DEBUG=maybe` or a `BIND_ADDRESS` that is not an IP address, stops it from
@@ -166,7 +164,8 @@ credentials, so it is bounded instead. Both refusals below answer with the same
   to be written fill the cap on their own, and then no file is deleted. At
   start, report files past the cap, as after lowering it, are deleted the same
   way. So the cap is 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`.
+  GiB is small enough for any host; set it to the space you can give
+  `DATA_DIR`.
 
 ### CORS
 
@@ -190,37 +189,17 @@ 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, 405
-for a method its route does not take, or 413 for declaring a body length over
+for a method its route does not take, or 413 for a body over the 1 MiB limit.
-the 1 MiB limit. A report whose body goes over the limit without declaring its
+Clients can make up any number of paths and methods, and each would add labels
-length reaches the route, is answered 413 there, and is recorded with that
+to the metrics for as long as the server runs. With neither set, nothing is
-status. Clients can make up any number of paths and methods, and each would add
+recorded and `/metrics` answers 404. One without the other stops the server
-labels to the metrics for as long as the server runs. With neither set, nothing
+from starting, with an error naming both.
-is recorded and `/metrics` answers 404. One without the other stops the server
-from starting, with an error naming both; so does a `METRICS_USERNAME`
-containing `:`, which basic auth cannot carry, with an error naming it.
-
-`/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
-minute, whatever their credentials. Past that it gets 429 with
-`Retry-After: 60`, and its credentials are not checked. The minute slides as it
-does for reports (see [Report limits](#report-limits)), so a scraper polling
-every 2 seconds or less often is never refused. This allowance is apart from the
-one for reports.
-
-### Sentry
-
-With `SENTRY_DSN` set, the server sends its errors to that Sentry project: each
-panic in a handler is reported there, under the release `netwatch-server-`
-followed by the server's version, and the request still gets 500 from the
-server's panic recovery. On shutdown the server waits up to 2 seconds for Sentry
-to finish sending. A DSN Sentry refuses stops the server from starting, with an
-error naming `SENTRY_DSN`. With it empty, Sentry is not set up, and nothing is
-sent to it.
 
 ## TODO
 
-The to-do list, this backend's open work included, is [TODO.md](../TODO.md) at
+- Add integration test that POSTs a report and verifies the compressed output
-the repo root.
+- Add report decompression/query endpoint
+- Add metrics (Prometheus) for buffer size, flush count, report count
 
 ## License
 

backend/cmd/netwatch-server/main_test.go

@@ -115,28 +115,6 @@ func TestMalformedConfigFileStopsTheStart(t *testing.T) {
 	}
 }
 
-// TestRefusedSentryDSNStopsTheStart: a SENTRY_DSN that Sentry refuses
-// stops the start, and the error, naming SENTRY_DSN, is logged as JSON.
-func TestRefusedSentryDSNStopsTheStart(t *testing.T) {
-	t.Setenv("SENTRY_DSN", "not-a-dsn")
-
-	ctx, cancel := context.WithTimeout(t.Context(), childTimeout)
-	defer cancel()
-
-	child, stdout, stderr := startServer(ctx, t, t.TempDir(), freePort(ctx, t))
-
-	err := child.Wait()
-	if child.ProcessState.ExitCode() != 1 {
-		t.Fatalf("server exit = %v, want exit status 1", err)
-	}
-
-	requireJSONLines(t, stdout, stderr)
-
-	if !strings.Contains(stdout.String(), "SENTRY_DSN") {
-		t.Fatalf("no error naming SENTRY_DSN in stdout:\n%s", stdout)
-	}
-}
-
 // startServer runs main() in a child process listening on
 // 127.0.0.1:port, with home as its HOME and working directory and its
 // data directory in home, so it touches nothing outside home. Its

backend/go.mod

@@ -4,7 +4,6 @@ go 1.25.5
 
 require (
 	github.com/99designs/basicauth-go v0.0.0-20230316000542-bf6f9cbbf0f8
-	github.com/getsentry/sentry-go v0.49.0
 	github.com/go-chi/chi/v5 v5.2.5
 	github.com/go-chi/cors v1.2.2
 	github.com/go-chi/httprate v0.16.0

backend/go.sum

@@ -4,22 +4,18 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
-github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
 github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
-github.com/getsentry/sentry-go v0.49.0 h1:Ehejknu1l023Ub7QoRBVLAI7g3Jnhqku4oWx4B4Sh5s=
-github.com/getsentry/sentry-go v0.49.0/go.mod h1:nuMJAoCfe1u0Bts2ocyNI+TW8HT84vRMqwA5Qq/SKUI=
 github.com/go-chi/chi/v5 v5.2.5 h1:Eg4myHZBjyvJmAFjFvWgrqDTXFyOzjj7YIm3L3mu6Ug=
 github.com/go-chi/chi/v5 v5.2.5/go.mod h1:X7Gx4mteadT3eDOMTsXzmI4/rwUpOwBHLpAfupzFJP0=
 github.com/go-chi/cors v1.2.2 h1:Jmey33TE+b+rB7fT8MUy1u0I4L+NARQlK6LhzKPSyQE=
 github.com/go-chi/cors v1.2.2/go.mod h1:sSbTewc+6wYHBBCW7ytsFSn836hqM7JxpglAy2Vzc58=
 github.com/go-chi/httprate v0.16.0 h1:8V5DH9j6pSK6UQoBsTpvMyFxycqaKEIToyPKzHJjUa8=
 github.com/go-chi/httprate v0.16.0/go.mod h1:A8lo+qRhk+s9LiuP5saS7XCGDXRXMcrueq0NfIuCa/I=
-github.com/go-errors/errors v1.4.2 h1:J6MZopCL4uSllY1OfXM374weqZFFItUbrImctkmUxIA=
-github.com/go-errors/errors v1.4.2/go.mod h1:sIVyrIiJhuEF+Pj9Ebtd6P/rEYROXFi3BopGUQ5a5Og=
 github.com/go-viper/mapstructure/v2 v2.4.0 h1:EBsztssimR/CONLSZZ04E8qAkxNYq4Qp9LvH92wZUgs=
 github.com/go-viper/mapstructure/v2 v2.4.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
@@ -40,12 +36,8 @@ github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
 github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
-github.com/pingcap/errors v0.11.4 h1:lFuQV/oaUMGcD2tqt+01ROSmJs75VG1ToEOkZIZ4nE4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pingcap/errors v0.11.4/go.mod h1:Oi8TUi2kEtXXLMJk9l1cGmz20kV3TaQ0usTwv5KuLY8=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
-github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v1.24.1 h1:JnJkREXzWxUdCuPFpIWZiPispT9xVV59uiuyR2bPlnU=
 github.com/prometheus/client_golang v1.24.1/go.mod h1:F+oSRECHg4sse5ucfYpYDeIv/hu68Zo0uoHKetWnzcE=
 github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
@@ -54,8 +46,8 @@ github.com/prometheus/common v0.70.1 h1:1HvjP4D5oL3t8RsPlwxA9onvvStjtIHYE5XuuwOi
 github.com/prometheus/common v0.70.1/go.mod h1:VdFUQDMZK3VLkurFUVhia6uys/0suUp86TJz5qbJRhc=
 github.com/prometheus/procfs v0.21.1 h1:GljZCt+zSTS+NZq88cyQ1LjZ+RCHp3uVuabBWA5+OJI=
 github.com/prometheus/procfs v0.21.1/go.mod h1:aB55Cww9pdSJVHk0hUf0inxWyyjPogFIjmHKYgMKmtY=
-github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
-github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/sagikazarmark/locafero v0.11.0 h1:1iurJgmM9G3PA/I+wWYIOw/5SyBtxapeHDcg+AAIFXc=
 github.com/sagikazarmark/locafero v0.11.0/go.mod h1:nVIGvgyzw595SUSUE6tvCp3YYTeHs15MvlmU87WwIik=
 github.com/slok/go-http-metrics v0.13.0 h1:lQDyJJx9wKhmbliyUsZ2l6peGnXRHjsjoqPt5VYzcP8=
@@ -101,7 +93,7 @@ golang.org/x/text v0.40.0/go.mod h1:hpnzDAfGV753zIKo+wk3u1bVKCGPbrnF7+7LBF/UHVY=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

backend/internal/config/config.go

@@ -49,10 +49,6 @@ var (
 		"METRICS_USERNAME and METRICS_PASSWORD must be set together, " +
 			"or neither",
 	)
-	errMetricsUsernameColon = errors.New(
-		"METRICS_USERNAME must not contain \":\", " +
-			"which basic auth cannot carry in a user name",
-	)
 )
 
 // Params defines the dependencies for Config.
@@ -193,12 +189,6 @@ func (s *Config) check() error {
 		return errMetricsCredentials
 	}
 
-	// Basic auth splits the credentials at the first ":", so with one
-	// in the user name every request to /metrics would get 401.
-	if strings.Contains(s.MetricsUsername, ":") {
-		return errMetricsUsernameColon
-	}
-
 	return checkOrigins(s.CORSAllowedOrigins)
 }
 

backend/internal/config/config_test.go

@@ -119,16 +119,6 @@ func TestMetricsCredentialsGoTogether(t *testing.T) {
 	}
 }
 
-// TestMetricsUsernameMustNotContainColon: basic auth splits the
-// credentials at the first ":", so such a user name would get 401 on
-// every request to /metrics.
-func TestMetricsUsernameMustNotContainColon(t *testing.T) {
-	t.Setenv("METRICS_USERNAME", "prom:etheus")
-	t.Setenv("METRICS_PASSWORD", "secret")
-
-	requireConfigError(t, "METRICS_USERNAME")
-}
-
 // TestCORSAllowedOriginsMustBeOrigins: "*" would let every origin in,
 // and an entry that is not a plain origin would match no page.
 func TestCORSAllowedOriginsMustBeOrigins(t *testing.T) {

backend/internal/server/export_test.go

@@ -1,21 +1,9 @@
 package server
 
-import "github.com/go-chi/chi/v5"
-
-// Router exposes the router to the external tests, which add routes
-// of their own to it after SetupRoutes.
-func (s *Server) Router() *chi.Mux {
-	return s.router
-}
-
 // MaxRequestBodyBytes exposes the router-wide body limit to the
 // external tests.
 const MaxRequestBodyBytes = maxRequestBodyBytes
 
-// MetricsRequestsPerMinute exposes the /metrics rate limit to the
-// external tests.
-const MetricsRequestsPerMinute = metricsRequestsPerMinute
-
 // ListenAddr exposes the address the server listens on to the
 // external tests.
 func (s *Server) ListenAddr() string {

backend/internal/server/routes.go

@@ -3,7 +3,6 @@ package server
 import (
 	"time"
 
-	sentryhttp "github.com/getsentry/sentry-go/http"
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/prometheus/client_golang/prometheus"
@@ -18,12 +17,6 @@ const (
 	// can mount s.mw.MaxBodyBytes with a smaller value to lower
 	// its bound, but cannot raise it: this cap runs first.
 	maxRequestBodyBytes int64 = 1 << 20 // 1 MiB
-
-	// metricsRequestsPerMinute is how many requests to /metrics each
-	// client address may make a minute, whatever their credentials. A
-	// scraper polling every 2 seconds sends half of it, which httprate
-	// never refuses.
-	metricsRequestsPerMinute = 60
 )
 
 // SetupRoutes configures the chi router with middleware and
@@ -39,12 +32,6 @@ func (s *Server) SetupRoutes() {
 	s.router.Use(s.mw.MaxBodyBytes(maxRequestBodyBytes))
 	s.router.Use(middleware.Timeout(requestTimeout))
 
-	// Sentry reports a panic, then panics again, so that s.mw.Recoverer
-	// still answers 500.
-	if s.params.Config.SentryDSN != "" {
-		s.router.Use(sentryhttp.New(sentryhttp.Options{Repanic: true}).Handle)
-	}
-
 	// The metrics go in a registry of this server's own, not in
 	// Prometheus' default one, which takes them only once per process.
 	registry := prometheus.NewRegistry()
@@ -72,14 +59,10 @@ func (s *Server) SetupRoutes() {
 			Post("/api/v1/reports", s.h.HandleReport())
 	})
 
-	// The rate limit comes before the basic auth, so a client past it
-	// gets 429 and its password is not checked.
 	if s.params.Config.MetricsUsername != "" {
-		s.router.With(
+		s.router.With(s.mw.MetricsAuth()).
-			s.mw.RateLimit(metricsRequestsPerMinute),
+			Get("/metrics", promhttp.HandlerFor(
-			s.mw.MetricsAuth(),
+				registry, promhttp.HandlerOpts{},
-		).Get("/metrics", promhttp.HandlerFor(
+			).ServeHTTP)
-			registry, promhttp.HandlerOpts{},
-		).ServeHTTP)
 	}
 }

backend/internal/server/routes_test.go

@@ -1,12 +1,10 @@
 package server_test
 
 import (
-	"io"
 	"net/http"
 	"net/http/httptest"
 	"strings"
 	"testing"
-	"time"
 
 	"sneak.berlin/go/netwatch/internal/config"
 	"sneak.berlin/go/netwatch/internal/globals"
@@ -17,7 +15,6 @@ import (
 	"sneak.berlin/go/netwatch/internal/reportbuf"
 	"sneak.berlin/go/netwatch/internal/server"
 
-	"github.com/getsentry/sentry-go"
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxtest"
 )
@@ -188,50 +185,6 @@ func TestMetricsBehindBasicAuth(t *testing.T) {
 	}
 }
 
-// TestMetricsAreRateLimited: a client that has used up its /metrics
-// allowance on wrong passwords gets 429 even with the right one, which
-// is then not checked, while another client behind the same nginx
-// still gets in.
-func TestMetricsAreRateLimited(t *testing.T) {
-	t.Setenv("METRICS_USERNAME", "prometheus")
-	t.Setenv("METRICS_PASSWORD", "right")
-	// As in the container: nginx connects from loopback and names the
-	// client in X-Forwarded-For.
-	t.Setenv("TRUSTED_PROXIES", "127.0.0.1/32")
-
-	srv := newServer(t)
-	srv.SetupRoutes()
-
-	get := func(client, password string) int {
-		rec := httptest.NewRecorder()
-		req := httptest.NewRequestWithContext(t.Context(),
-			http.MethodGet, "/metrics", http.NoBody)
-		req.RemoteAddr = "127.0.0.1:40000"
-		req.Header.Set("X-Forwarded-For", client)
-		req.SetBasicAuth("prometheus", password)
-		srv.ServeHTTP(rec, req)
-
-		return rec.Code
-	}
-
-	for i := range server.MetricsRequestsPerMinute {
-		if code := get("203.0.113.7", "wrong"); code != http.StatusUnauthorized {
-			t.Fatalf("guess %d: status = %d, want %d",
-				i+1, code, http.StatusUnauthorized)
-		}
-	}
-
-	if code := get("203.0.113.7", "right"); code != http.StatusTooManyRequests {
-		t.Fatalf("right password past the limit: status = %d, want %d",
-			code, http.StatusTooManyRequests)
-	}
-
-	if code := get("203.0.113.8", "right"); code != http.StatusOK {
-		t.Fatalf("another client: status = %d, want %d",
-			code, http.StatusOK)
-	}
-}
-
 // TestMetricsInTwoServers: two servers in one process can both have
 // metrics on.
 func TestMetricsInTwoServers(t *testing.T) {
@@ -243,70 +196,6 @@ func TestMetricsInTwoServers(t *testing.T) {
 	}
 }
 
-// TestSentry: with SENTRY_DSN empty there is no Sentry client. With it
-// pointing at a local server standing in for Sentry, a panic in a
-// handler reaches that server, and the request still gets the 500 from
-// the panic recovery.
-func TestSentry(t *testing.T) {
-	const panicMessage = "handler panic for TestSentry"
-
-	// sentry.Init sets the client for the whole process; take it away
-	// again so that no other test reports to Sentry.
-	t.Cleanup(func() { sentry.CurrentHub().BindClient(nil) })
-
-	t.Setenv("SENTRY_DSN", "")
-	newServer(t)
-
-	if sentry.CurrentHub().Client() != nil {
-		t.Fatal("a Sentry client exists with SENTRY_DSN empty")
-	}
-
-	// The body of the first request the stand-in for Sentry receives.
-	received := make(chan string, 1)
-
-	sentryServer := httptest.NewServer(http.HandlerFunc(
-		func(_ http.ResponseWriter, r *http.Request) {
-			body, _ := io.ReadAll(r.Body)
-
-			select {
-			case received <- string(body):
-			default:
-			}
-		},
-	))
-	defer sentryServer.Close()
-
-	t.Setenv("SENTRY_DSN",
-		"http://key@"+sentryServer.Listener.Addr().String()+"/1")
-
-	srv := newServer(t)
-	srv.SetupRoutes()
-	srv.Router().Get("/panic", func(http.ResponseWriter, *http.Request) {
-		panic(panicMessage)
-	})
-
-	rec := httptest.NewRecorder()
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodGet, "/panic", http.NoBody)
-	srv.ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusInternalServerError {
-		t.Fatalf("status = %d, want %d",
-			rec.Code, http.StatusInternalServerError)
-	}
-
-	// Sentry sends from a goroutine of its own.
-	select {
-	case body := <-received:
-		if !strings.Contains(body, panicMessage) {
-			t.Fatalf("the Sentry server received no report of the panic:\n%s",
-				body)
-		}
-	case <-time.After(5 * time.Second):
-		t.Fatal("nothing reached the Sentry server")
-	}
-}
-
 // TestHealthCheckRejectsOversizeBody sends the health check, which
 // never reads its body, a body one byte over the limit. Only the
 // router-wide body limit can reject it.

backend/internal/server/server.go

@@ -7,10 +7,8 @@ package server
 
 import (
 	"context"
-	"fmt"
 	"log/slog"
 	"net/http"
-	"time"
 
 	"sneak.berlin/go/netwatch/internal/config"
 	"sneak.berlin/go/netwatch/internal/globals"
@@ -18,15 +16,10 @@ import (
 	"sneak.berlin/go/netwatch/internal/logger"
 	"sneak.berlin/go/netwatch/internal/middleware"
 
-	"github.com/getsentry/sentry-go"
 	"github.com/go-chi/chi/v5"
 	"go.uber.org/fx"
 )
 
-// sentryFlushTimeout is how long shutdown waits for Sentry to send
-// what it still holds.
-const sentryFlushTimeout = 2 * time.Second
-
 // Params defines the dependencies for Server.
 type Params struct {
 	fx.In
@@ -63,11 +56,6 @@ func New(
 	s.log = params.Logger.Get()
 	s.shutdowner = params.Shutdowner
 
-	err := s.enableSentry()
-	if err != nil {
-		return nil, err
-	}
-
 	lc.Append(fx.Hook{
 		OnStart: func(_ context.Context) error {
 			// Build the router and http.Server synchronously
@@ -99,37 +87,10 @@ func (s *Server) ServeHTTP(
 	s.router.ServeHTTP(w, r)
 }
 
-// enableSentry sets Sentry up when SENTRY_DSN is set, so that
-// SetupRoutes can report panics to it. With SENTRY_DSN empty it does
-// nothing. A DSN Sentry refuses stops the start.
-func (s *Server) enableSentry() error {
-	if s.params.Config.SentryDSN == "" {
-		return nil
-	}
-
-	err := sentry.Init(sentry.ClientOptions{
-		Dsn:     s.params.Config.SentryDSN,
-		Release: s.params.Globals.Appname + "-" + s.params.Globals.Version,
-	})
-	if err != nil {
-		return fmt.Errorf("SENTRY_DSN: %w", err)
-	}
-
-	s.log.Info("sentry error reporting activated")
-
-	return nil
-}
-
 // shutdown gracefully stops the HTTP server within the
-// deadline of the context fx provides for OnStop, then gives
+// deadline of the context fx provides for OnStop.
-// Sentry, if set up, time to send what it still holds.
 func (s *Server) shutdown(ctx context.Context) error {
 	err := s.httpServer.Shutdown(ctx)
-
-	if s.params.Config.SentryDSN != "" {
-		sentry.Flush(sentryFlushTimeout)
-	}
-
 	if err != nil {
 		s.log.Error("server clean shutdown failed", "error", err)
 

script/add-dependency

@@ -1,30 +0,0 @@
-#!/bin/sh
-# script/add-dependency: add a frontend package, or move one to another
-# version, with yarn add, which changes package.json and yarn.lock
-# together; then install from yarn.lock with --frozen-lockfile, as
-# script/bootstrap does, to show it installs as written. --dev because
-# no frontend package is needed when the page runs: it ships as the
-# built dist/.
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-usage() {
-    echo "usage: make add-dependency PACKAGE=<name>@<version>" >&2
-    exit 2
-}
-
-main() {
-    # Exactly one package. A value beginning with - would reach yarn as
-    # an option; yarn would quietly drop all but the first of several
-    # packages given in one value.
-    [ "$#" -eq 1 ] || usage
-    case "$1" in
-    "" | -* | *[[:space:]]*) usage ;;
-    esac
-    cd "$ROOT"
-    yarn add --dev "$1"
-    yarn install --frozen-lockfile
-}
-
-main "$@"

script/bootstrap

@@ -17,13 +17,11 @@
 #
 # golangci-lint is not installed: make lint runs it in Docker, which
 # this script does not install either.
-#
-# Unlike the org model: Go and gcc for backend/, a newer node for eslint.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
-# Pinned versions, 2026-07-06
+# Pinned versions, 2026-07-07
 NODE_VERSION="22.17.0"
 # The oldest node the frontend's dependencies accept: the "engines"
 # field of eslint 10.12.0, the most demanding of them, asks for 22.13.0

script/build

@@ -1,13 +0,0 @@
-#!/bin/sh
-# script/build: build the frontend for production into dist/. The Go
-# backend is built by backend/script/build.
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-main() {
-    cd "$ROOT"
-    yarn build
-}
-
-main "$@"

script/dev

@@ -1,13 +0,0 @@
-#!/bin/sh
-# script/dev: run the frontend's Vite dev server. It proxies /api to a
-# netwatch-server running locally (see vite.config.js).
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-main() {
-    cd "$ROOT"
-    yarn dev
-}
-
-main "$@"

script/fmt

@@ -1,7 +1,6 @@
 #!/bin/sh
 # script/fmt: format the whole repo (writes): prettier over everything
 # it understands, then gofmt over the Go backend.
-# The org model formats only markdown; this repo also has JS and Go.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"

script/fmt-check

@@ -1,7 +1,6 @@
 #!/bin/sh
 # script/fmt-check: check formatting across the whole repo (read-only).
 # Same scope as script/fmt, but fails instead of writing.
-# The org model checks only markdown; this repo also has JS and Go.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"

script/frontend-fmt

@@ -1,7 +1,7 @@
 #!/bin/sh
 # script/frontend-fmt: format the frontend and every other file prettier
-# understands, repo-wide (writes), the markdown in backend/ included.
+# understands, repo-wide (writes). backend/ is in .prettierignore; Go
-# Prettier does not read Go; backend/script/fmt formats the Go sources.
+# sources are formatted by backend/script/fmt.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"

script/install-precommit

@@ -8,8 +8,8 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 main() {
     cd "$ROOT"
     hook=".git/hooks/pre-commit"
-    printf '#!/bin/sh\nset -e\nscript/precommit\n' > .git/hooks/pre-commit
+    printf '#!/bin/sh\nset -e\nscript/precommit\n' > "$hook"
-    chmod +x .git/hooks/pre-commit
+    chmod +x "$hook"
     echo "pre-commit hook installed: runs script/precommit"
 }
 

script/tidy

@@ -1,13 +0,0 @@
-#!/bin/sh
-# script/tidy: run go mod tidy in backend/, which adds the modules the
-# Go sources import, drops those they no longer do, and updates go.sum.
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-main() {
-    cd "$ROOT/backend"
-    go mod tidy
-}
-
-main "$@"

src/main.js

@@ -8,8 +8,6 @@
 // display their real value in the latency figure. The history buffer holds
 // maxHistoryPoints samples (historyDuration / updateInterval).
 // reportInterval is how often collected samples are POSTed to the backend.
-// The interval menu changes updateInterval while the page runs; the
-// getters compute their values from it each time they are read.
 export const CONFIG = {
     updateInterval: 3000,
     maxHistoryPoints: 100,
@@ -30,39 +28,6 @@ export const CONFIG = {
         return [0, 1, 2, 3, 4, 5].map((i) => Math.round((d * i) / 5));
     },
     canvasHeight: 96,
-    // A latency figure and its sparkline take the color of the first entry
-    // whose limit, in ms, the latency is below.
-    latencyColors: [
-        { below: 50, hex: "#22c55e", className: "text-green-500" },
-        { below: 100, hex: "#84cc16", className: "text-lime-500" },
-        { below: 200, hex: "#eab308", className: "text-yellow-500" },
-        { below: 500, hex: "#f97316", className: "text-orange-500" },
-        { below: Infinity, hex: "#ef4444", className: "text-red-500" },
-    ],
-    // The health is offline when more than offlineTimeouts WAN hosts timed
-    // out or were unreachable and at most offlineReachable answered;
-    // otherwise degraded when more than degradedTimeouts timed out or were
-    // unreachable; otherwise slow when more than slowHosts answered after
-    // more than slowLatency ms.
-    offlineTimeouts: 10,
-    offlineReachable: 4,
-    degradedTimeouts: 4,
-    slowHosts: 3,
-    slowLatency: 1000,
-    // The debug log keeps its last maxLogEntries lines.
-    maxLogEntries: 1000,
-    // A gateway candidate that has not answered after gatewayTimeout ms is
-    // passed over.
-    gatewayTimeout: 1500,
-    // When no WAN host answers, the recovery probe checks recoveryProbeHosts
-    // random ones every recoveryProbeInterval ms.
-    recoveryProbeHosts: 4,
-    recoveryProbeInterval: 500,
-    // The rows are sorted after the first round that is not discarded, then
-    // every roundsPerSort rounds.
-    roundsPerSort: 10,
-    // The sparklines are sized and drawn again resizeDelay ms after start.
-    resizeDelay: 100,
 };
 
 // WAN endpoints to monitor. These are used for the aggregate health/stats
@@ -147,8 +112,7 @@ const debugLog = [];
 const log = (() => {
     function append(level, message) {
         debugLog.push({ timestamp: new Date(), level, message });
-        if (debugLog.length > CONFIG.maxLogEntries)
+        if (debugLog.length > 1000) debugLog.splice(0, debugLog.length - 1000);
-            debugLog.splice(0, debugLog.length - CONFIG.maxLogEntries);
         const panel = document.getElementById("debug-panel");
         if (panel && !panel.classList.contains("hidden")) renderDebugLog();
     }
@@ -208,10 +172,7 @@ async function detectGateway() {
         const result = await Promise.any(
             GATEWAY_CANDIDATES.map(async (url) => {
                 const controller = new AbortController();
-                const timeoutId = setTimeout(
+                const timeoutId = setTimeout(() => controller.abort(), 1500);
-                    () => controller.abort(),
-                    CONFIG.gatewayTimeout,
-                );
                 try {
                     await fetch(url, {
                         method: "GET",
@@ -236,35 +197,11 @@ async function detectGateway() {
 
 // --- App State ---------------------------------------------------------------
 
-// The min, max, median and average of latencies, a list of numbers, or all
-// null when it is empty. The median of an even count is the mean of the
-// middle two; it and the average are rounded.
-function latencyStats(latencies) {
-    if (latencies.length === 0)
-        return { min: null, max: null, med: null, avg: null };
-    const sorted = [...latencies].sort((a, b) => a - b);
-    const mid = Math.floor(sorted.length / 2);
-    return {
-        min: sorted[0],
-        max: sorted[sorted.length - 1],
-        med:
-            sorted.length % 2
-                ? sorted[mid]
-                : Math.round((sorted[mid - 1] + sorted[mid]) / 2),
-        avg: Math.round(
-            latencies.reduce((a, b) => a + b, 0) / latencies.length,
-        ),
-    };
-}
-
 export class HostState {
     constructor(host, pinned = false) {
         this.name = host.name;
         this.url = host.url;
-        // Each entry is either a check's result, { timestamp, latency,
+        this.history = []; // { timestamp, latency, paused }
-        // error }, or a round skipped while paused, { timestamp,
-        // latency: null, paused: true }.
-        this.history = [];
         this.lastLatency = null;
         this.status = "pending"; // 'online' | 'offline' | 'error' | 'pending'
         this.pinned = pinned;
@@ -288,16 +225,38 @@ export class HostState {
         this._trim();
     }
 
-    // The min, max, median and average latency of the checks in the history
+    averageLatency() {
-    // that got an answer.
+        const valid = this.history.filter((p) => p.latency !== null);
-    historyStats() {
+        if (valid.length === 0) return null;
-        return latencyStats(
+        return Math.round(
-            this.history
+            valid.reduce((s, p) => s + p.latency, 0) / valid.length,
-                .filter((p) => p.latency !== null)
-                .map((p) => p.latency),
         );
     }
 
+    minLatency() {
+        const valid = this.history.filter((p) => p.latency !== null);
+        if (valid.length === 0) return null;
+        return Math.min(...valid.map((p) => p.latency));
+    }
+
+    maxLatency() {
+        const valid = this.history.filter((p) => p.latency !== null);
+        if (valid.length === 0) return null;
+        return Math.max(...valid.map((p) => p.latency));
+    }
+
+    medianLatency() {
+        const sorted = this.history
+            .filter((p) => p.latency !== null)
+            .map((p) => p.latency)
+            .sort((a, b) => a - b);
+        if (sorted.length === 0) return null;
+        const mid = Math.floor(sorted.length / 2);
+        return sorted.length % 2
+            ? sorted[mid]
+            : Math.round((sorted[mid - 1] + sorted[mid]) / 2);
+    }
+
     _trim() {
         while (this.history.length > CONFIG.maxHistoryPoints)
             this.history.shift();
@@ -312,10 +271,6 @@ export class AppState {
         this.local = localHosts.map((h) => new HostState(h));
         this.paused = false;
         this.tickCount = 0;
-        // The recovery probe's timer, null while it is not running, and the
-        // checks it started last.
-        this._recoveryProbeId = null;
-        this._recoveryProbeChecks = null;
     }
 
     get allHosts() {
@@ -324,13 +279,33 @@ export class AppState {
 
     /** WAN-only stats from latest sample (excludes local) */
     wanStats() {
-        const latencies = this.wan
+        const reachable = this.wan.filter((h) => h.lastLatency !== null);
-            .filter((h) => h.lastLatency !== null)
+        const latencies = reachable.map((h) => h.lastLatency);
-            .map((h) => h.lastLatency);
+        const total = this.wan.length;
+        if (latencies.length === 0)
+            return {
+                reachable: 0,
+                total,
+                min: null,
+                max: null,
+                med: null,
+                avg: null,
+            };
+        const sorted = [...latencies].sort((a, b) => a - b);
+        const mid = Math.floor(sorted.length / 2);
+        const med =
+            sorted.length % 2
+                ? sorted[mid]
+                : Math.round((sorted[mid - 1] + sorted[mid]) / 2);
         return {
             reachable: latencies.length,
-            total: this.wan.length,
+            total,
-            ...latencyStats(latencies),
+            min: Math.min(...latencies),
+            max: Math.max(...latencies),
+            med,
+            avg: Math.round(
+                latencies.reduce((a, b) => a + b, 0) / latencies.length,
+            ),
         };
     }
 
@@ -356,16 +331,12 @@ export class AppState {
         const timeouts = this.wan.filter(
             (h) => h.status === "error" || h.status === "offline",
         ).length;
-        if (
+        if (timeouts > 10 && reachable <= 4) return "offline";
-            timeouts > CONFIG.offlineTimeouts &&
+        if (timeouts > 4) return "degraded";
-            reachable <= CONFIG.offlineReachable
-        )
-            return "offline";
-        if (timeouts > CONFIG.degradedTimeouts) return "degraded";
         const slow = this.wan.filter(
-            (h) => h.lastLatency !== null && h.lastLatency > CONFIG.slowLatency,
+            (h) => h.lastLatency !== null && h.lastLatency > 1000,
         ).length;
-        if (slow > CONFIG.slowHosts) return "slow";
+        if (slow > 3) return "slow";
         return "healthy";
     }
 
@@ -577,13 +548,21 @@ export async function measureLatency(url, signal) {
 
 export function latencyHex(latency) {
     if (latency === null) return "#6b7280";
-    return CONFIG.latencyColors.find((c) => latency < c.below).hex;
+    if (latency < 50) return "#22c55e";
+    if (latency < 100) return "#84cc16";
+    if (latency < 200) return "#eab308";
+    if (latency < 500) return "#f97316";
+    return "#ef4444";
 }
 
 export function latencyClass(latency, status) {
     if (status === "offline" || status === "error" || latency === null)
         return "text-gray-500";
-    return CONFIG.latencyColors.find((c) => latency < c.below).className;
+    if (latency < 50) return "text-green-500";
+    if (latency < 100) return "text-lime-500";
+    if (latency < 200) return "text-yellow-500";
+    if (latency < 500) return "text-orange-500";
+    return "text-red-500";
 }
 
 // --- Sparkline Renderer ------------------------------------------------------
@@ -601,8 +580,8 @@ class SparklineRenderer {
         const ch = h - m.top - m.bottom;
 
         ctx.clearRect(0, 0, w, h);
-        SparklineRenderer._drawYAxis(ctx, w, m, ch);
+        SparklineRenderer._drawYAxis(ctx, w, h, m, ch);
-        SparklineRenderer._drawXAxis(ctx, h, m, cw);
+        SparklineRenderer._drawXAxis(ctx, w, h, m, cw);
 
         const len = history.length;
         const pw = cw / (CONFIG.maxHistoryPoints - 1);
@@ -618,7 +597,7 @@ class SparklineRenderer {
         SparklineRenderer._drawTip(ctx, history, getX, getY);
     }
 
-    static _drawYAxis(ctx, w, m, ch) {
+    static _drawYAxis(ctx, w, h, m, ch) {
         ctx.font = "300 12px monospace";
         ctx.textAlign = "right";
         ctx.textBaseline = "middle";
@@ -635,7 +614,7 @@ class SparklineRenderer {
         }
     }
 
-    static _drawXAxis(ctx, h, m, cw) {
+    static _drawXAxis(ctx, w, h, m, cw) {
         ctx.textAlign = "center";
         ctx.textBaseline = "top";
         for (const tick of CONFIG.xAxisTicks) {
@@ -723,18 +702,7 @@ class SparklineRenderer {
 // horizontally.
 const STATUS_TEXT_CLASS = "status-text text-xs text-right col-span-2 mt-5";
 
-// Escapes text for HTML, so it shows as written inside an element or a
+function hostRowHTML(host, index, showPin = true) {
-// quoted attribute and is never read as markup.
-function escapeHTML(text) {
-    return text
-        .replaceAll("&", "&amp;")
-        .replaceAll("<", "&lt;")
-        .replaceAll(">", "&gt;")
-        .replaceAll('"', "&quot;")
-        .replaceAll("'", "&#39;");
-}
-
-export function hostRowHTML(host, index, showPin = true) {
     const pinColor = host.pinned
         ? "text-blue-500"
         : "text-gray-600 hover:text-gray-400";
@@ -753,12 +721,12 @@ export function hostRowHTML(host, index, showPin = true) {
         <div class="w-[420px] flex-shrink-0 grid grid-cols-[minmax(0,1fr)_auto] items-center">
           <div class="flex items-center gap-2 min-w-[200px]">
             <div class="w-3 h-3 rounded-full flex-shrink-0 bg-[#6b7280]"></div>
-            <span class="font-medium text-white truncate">${escapeHTML(host.name)}</span>
+            <span class="font-medium text-white truncate">${host.name}</span>
           </div>
           <div class="latency-value text-4xl font-bold tabular-nums text-right mt-3" data-host="${index}">
             <span class="text-gray-500">---</span>
           </div>
-          <a href="${escapeHTML(host.url)}" target="_blank" rel="noopener" class="text-xs text-gray-500 truncate block col-span-2 -mt-2">${escapeHTML(host.url)}</a>
+          <a href="${host.url}" target="_blank" rel="noopener" class="text-xs text-gray-500 truncate block col-span-2 -mt-2">${host.url}</a>
           <div class="${STATUS_TEXT_CLASS} text-gray-500" data-host="${index}">waiting...</div>
         </div>
         <div class="flex-grow sparkline-container rounded overflow-hidden border border-gray-700/30">
@@ -857,7 +825,7 @@ function buildUI(state) {
       </div>
 
       <footer class="mt-8 text-center text-gray-600 text-xs">
-        <p>Latency measured via GET requests | CORS restrictions may affect some measurements</p>
+        <p>Latency measured via GET requests | IPv4 only | CORS restrictions may affect some measurements</p>
         <p class="mt-2">
           <span class="inline-block w-3 h-3 rounded-full bg-green-500 mr-1 align-middle"></span>&lt;50ms
           <span class="inline-block w-3 h-3 rounded-full bg-lime-500 mr-1 ml-3 align-middle"></span>&lt;100ms
@@ -924,7 +892,10 @@ function updateHostRow(host, index) {
         latencyEl.innerHTML = `<span class="text-gray-500">---</span>`;
     }
 
-    const { min, med, avg, max } = host.historyStats();
+    const avg = host.averageLatency();
+    const med = host.medianLatency();
+    const min = host.minLatency();
+    const max = host.maxLatency();
     if (host.status === "online" && avg !== null) {
         statusEl.innerHTML = statusStatsHTML([
             ["min", min],
@@ -1071,16 +1042,14 @@ function renderDebugLog() {
         info: "text-gray-300",
         debug: "text-gray-500",
     };
-    el.replaceChildren(
+    el.innerHTML = debugLog
-        ...debugLog.map((entry) => {
+        .map((entry) => {
             const ts = formatUTCTimestamp(entry.timestamp);
+            const cls = levelColors[entry.level] || "text-gray-400";
             const lvl = entry.level.toUpperCase().padEnd(7);
-            const line = document.createElement("div");
+            return `<div class="${cls}">${ts} ${lvl} ${entry.message}</div>`;
-            line.className = levelColors[entry.level] || "text-gray-400";
+        })
-            line.textContent = `${ts} ${lvl} ${entry.message}`;
+        .join("");
-            return line;
-        }),
-    );
     el.scrollTop = el.scrollHeight;
 }
 
@@ -1191,9 +1160,8 @@ export async function tick(state, signal, onOffline) {
     // rows whose check ended before the resume still read "paused"
     state.allHosts.forEach((host, i) => updateHostRow(host, i));
 
-    // Sort after the first real check, then every CONFIG.roundsPerSort
+    // Sort after the first real check, then every 10 ticks thereafter
-    // ticks thereafter
+    if (state.tickCount === 2 || state.tickCount % 10 === 1) {
-    if (state.tickCount === 2 || state.tickCount % CONFIG.roundsPerSort === 1) {
         sortAndRebuildWAN(state);
     }
 
@@ -1216,10 +1184,9 @@ export async function tick(state, signal, onOffline) {
 
 // --- Recovery Probe ----------------------------------------------------------
 
-// When offline, check CONFIG.recoveryProbeHosts random WAN hosts every
+// When offline, check 4 random WAN hosts every 500ms, giving up the checks
-// CONFIG.recoveryProbeInterval ms, giving up the checks started one interval
+// started 500ms before, so at most 4 are ever waiting. As soon as one
-// before, so at most that many are ever waiting. As soon as one answers,
+// answers, stop probing and start a new round at once.
-// stop probing and start a new round at once.
 function startRecoveryProbe(state, startRounds) {
     if (state._recoveryProbeId) return; // already running
     const candidates = [...state.wan];
@@ -1227,7 +1194,7 @@ function startRecoveryProbe(state, startRounds) {
         const j = Math.floor(Math.random() * (i + 1));
         [candidates[i], candidates[j]] = [candidates[j], candidates[i]];
     }
-    const canaries = candidates.slice(0, CONFIG.recoveryProbeHosts);
+    const canaries = candidates.slice(0, 4);
     log.notice(
         `Recovery probe started (${canaries.map((h) => h.name).join(", ")})`,
     );
@@ -1244,7 +1211,7 @@ function startRecoveryProbe(state, startRounds) {
                 startRounds();
             });
         }
-    }, CONFIG.recoveryProbeInterval);
+    }, 500);
 }
 
 function stopRecoveryProbe(state) {
@@ -1508,7 +1475,7 @@ async function init() {
         });
 
     window.addEventListener("resize", () => handleResize(state));
-    setTimeout(() => handleResize(state), CONFIG.resizeDelay);
+    setTimeout(() => handleResize(state), 100);
 }
 
 // Bootstrap only when loaded as the page: a real DOM containing the #app

test/unit/main.test.js

@@ -8,7 +8,6 @@ import {
     AppState,
     CONFIG,
     greyOutUI,
-    hostRowHTML,
     HostState,
     humanDuration,
     latencyClass,
@@ -231,32 +230,6 @@ test("at a 30000ms interval, after the user pauses and resumes during a round, n
     }
 });
 
-// The page shows < > " & and ' in a row's markup as
-// < > " & and '.
-test(`a target whose name and URL hold < > " & and ' shows those characters in its row`, () => {
-    const host = new HostState({
-        name: `<b>"x" & 'y'</b>`,
-        url: `https://x.test/<b>?a="x"&b='y'`,
-    });
-    const row = hostRowHTML(host, 0);
-    assert.doesNotMatch(row, /<b>/);
-    assert.ok(
-        row.includes(
-            ">&lt;b&gt;&quot;x&quot; &amp; &#39;y&#39;&lt;/b&gt;</span>",
-        ),
-    );
-    assert.ok(
-        row.includes(
-            'href="https://x.test/&lt;b&gt;?a=&quot;x&quot;&amp;b=&#39;y&#39;"',
-        ),
-    );
-    assert.ok(
-        row.includes(
-            ">https://x.test/&lt;b&gt;?a=&quot;x&quot;&amp;b=&#39;y&#39;</a>",
-        ),
-    );
-});
-
 for (const [seconds, text] of [
     [0, "0s"],
     [1, "1s"],
@@ -347,35 +320,19 @@ for (const { history, latencies, statistics } of [
     },
 ]) {
     test(`a target's min, max, average and median latency over ${history}`, () => {
-        const { min, max, avg, med } = hostAfter(latencies).historyStats();
+        const host = hostAfter(latencies);
-        assert.deepEqual({ min, max, average: avg, median: med }, statistics);
+        assert.deepEqual(
+            {
+                min: host.minLatency(),
+                max: host.maxLatency(),
+                average: host.averageLatency(),
+                median: host.medianLatency(),
+            },
+            statistics,
+        );
     });
 }
 
-// The summary's figures come from each WAN target's last check, by the same
-// rules as a target's own: here four answered, one was found unreachable
-// and the rest have not been checked yet. The median, 22.5, and the
-// average, 21.25, are rounded.
-test("the summary's min, max, median and average latency over the WAN targets' last checks", () => {
-    const state = new AppState([]);
-    [30, 10, null, 25, 20].forEach((latency, i) =>
-        state.wan[i].pushSample(
-            Date.now(),
-            latency === null
-                ? { latency: null, error: "unreachable" }
-                : { latency, error: null },
-        ),
-    );
-    assert.deepEqual(state.wanStats(), {
-        reachable: 4,
-        total: state.wan.length,
-        min: 10,
-        max: 30,
-        med: 23,
-        avg: 21,
-    });
-});
-
 // 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.

test/viewport/README.md

@@ -77,7 +77,7 @@ the internet, so the app's latency probes cannot reach anything real. The
 harness answers them itself from a fixed delay table, with a deterministic
 fraction failed outright, so the rows render a realistic spread of one-, two-
 and three-digit latencies plus some unreachable rows. That spread is what the
-layout has to survive; a `---` placeholder in every row would not exercise it.
+layout has to survive; 24 identical `---` placeholders would not exercise it.
 
 ## What this cannot verify
 
@@ -104,11 +104,10 @@ Everything else this issue was actually about — does the layout reflow, does
 anything overflow, is content clipped, are the controls big enough — is a
 function of viewport width and CSS, and is covered above.
 
-## Relation to the unit tests
+## Relation to the unit test framework (#21)
 
-Complementary layers, not two stacks. The unit tests in `test/unit/`, which
+Complementary layers, not two stacks. `vitest` (#21) will exercise module-level
-`make test` runs with Node's built-in test runner, exercise the functions
+logic in-process with no browser. This harness exercises rendered layout in a
-`src/main.js` exports in-process with no browser. This harness exercises
+real engine and is the only thing here that can see a media query. Neither
-rendered layout in a real engine and is the only thing here that can see a media
+replaces the other; assertions about computed styles and element geometry belong
-query. Neither replaces the other; assertions about computed styles and element
+here, assertions about functions belong in `vitest`.
-geometry belong here, assertions about functions belong in `test/unit/`.