build: one image, nginx in front of the backend on loopback (closes #52)

The root Dockerfile builds the only image; Dockerfile.backend is gone.
Its stages: lint, a Go stage that runs the tests and builds
netwatch-server, the node stage, and an nginx runtime. nginx serves
dist/ on 8080 and proxies /api/ and /.well-known/healthcheck to the
backend on 127.0.0.1:8081. bin/entrypoint.sh starts both, turns TERM or
INT into a stop of both, and exits non-zero when either exits on its
own. The backend runs as user netwatch and keeps reports on the /data
volume. New setting BIND_ADDRESS (empty: every interface). STOPSIGNAL is
SIGTERM, since the nginx image's SIGQUIT would miss the entrypoint.
script/docker is the org model verbatim.

Model: opus-5-5

.gitea/workflows/check.yml

@@ -6,7 +6,5 @@ jobs:
         steps:
             # actions/checkout v4.2.2, 2026-02-22
             - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-            # script/cibuild bootstraps, runs every check and builds the
-            # image. script/bootstrap links what it installs into
-            # ~/.local/bin, so that has to be on PATH for the rest.
-            - run: PATH="$HOME/.local/bin:$PATH" script/cibuild
+            # script/cibuild builds the image, whose stages run every check.
+            - run: script/cibuild

Dockerfile

@@ -68,29 +68,18 @@ FROM nginx@sha256:15e96e59aa3b0aada3a121296e3bce117721f42d88f5f64217ef4b18f458c6
 RUN addgroup -g 1000 -S netwatch && \
     adduser -u 1000 -S netwatch -G netwatch
 
-# At start-up the nginx image renders every template here into
-# conf.d; bin/entrypoint.sh says how.
 RUN rm /etc/nginx/conf.d/default.conf
-COPY nginx.conf /etc/nginx/templates/netwatch.conf.template
-COPY security-headers.conf /etc/nginx/security-headers.conf
+COPY nginx.conf /etc/nginx/conf.d/netwatch.conf
 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
 
-# bin/entrypoint.sh creates DATA_DIR at start and gives it and /data to
-# the netwatch user, whatever is mounted there.
 ENV DATA_DIR=/data/reports
+RUN mkdir -p /data/reports && chown -R netwatch:netwatch /data
 VOLUME /data
 
-# The default public port; PORT changes it.
 EXPOSE 8080
 
-# Requests the backend's health check through nginx, on the port from
-# PORT, so it fails unless both answer. upaas reads the result 60
-# seconds after a deploy and fails the deploy unless it is healthy.
-HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
-    CMD wget -q -O /dev/null "http://127.0.0.1:${PORT:-8080}/.well-known/healthcheck"
-
 # The nginx image stops its container with SIGQUIT; the entrypoint
 # acts on TERM and INT.
 STOPSIGNAL SIGTERM

README.md

@@ -36,12 +36,12 @@ The Go backend in `backend/` has its own `script/` directory and shim Makefile
 (see [backend/README.md](backend/README.md)). The root scripts cover both
 halves, so the root `make check` fails if either one is broken. We provide:
 
-- `script/bootstrap` — install all dependencies (the pinned node via nvm unless
-  one new enough for the frontend's dependencies is installed, yarn via
-  corepack, `yarn install --frozen-lockfile`, the pinned Go unless one at least
-  as new as `backend/go.mod` asks for is installed, and the Go modules), linking
-  what it installs itself into `~/.local/bin`, which has to be on `PATH`. It
-  installs no Go linter and not Docker: `make lint` runs the linter in Docker
+- `script/bootstrap` — install all dependencies (pinned node via nvm if needed,
+  yarn via corepack, `yarn install --frozen-lockfile`, the pinned Go unless one
+  at least as new as `backend/go.mod` asks for is installed, and the Go
+  modules), linking what it installs itself into `~/.local/bin`, which has to be
+  on `PATH`. It installs no Go linter and not Docker: `make lint` runs the
+  linter in Docker
 - `script/setup` — make a fresh clone ready for development: bootstrap plus the
   git pre-commit hook
 - `script/projectname` — print the project name (used for the Docker image tag)
@@ -65,8 +65,7 @@ halves, so the root `make check` fails if either one is broken. We provide:
   `script/check`: it needs Docker and takes minutes.
 - `script/docker` — build the image from `Dockerfile` without the build cache,
   tagged `netwatch` via `script/projectname`
-- `script/cibuild` — CI entrypoint: runs `script/bootstrap` and `script/check`,
-  then builds the image as `script/docker` does, without the build cache
+- `script/cibuild` — CI entrypoint: builds the image
 - `script/precommit` — run by the git pre-commit hook; runs `script/check`
 - `script/install-precommit` — install the git pre-commit hook
 
@@ -185,57 +184,16 @@ container: nginx serves the built frontend and passes `/api/` and
 only inside the container, on `127.0.0.1:8081`. The image:
 
 - Listens on port 8080 by default (override with `PORT` env var)
-- Takes the client address from `X-Forwarded-For` only on requests from the
-  reverse proxies named in `TRUSTED_PROXIES`, and by default from none
+- Trusts `X-Forwarded-For` from RFC1918 reverse proxies (10/8, 172.16/12,
+  192.168/16)
 - Sends access logs to stdout
 - Caches static assets with immutable headers
-- Sends the security headers `REPO_POLICIES.md` requires on every response, as
-  `security-headers.conf` sets them, in place of the backend's own
 - Stores reports in `DATA_DIR`, `/data/reports` by default, on the `/data`
-  volume. Before the backend starts, the image creates `DATA_DIR` and gives it
-  and `/data` to user `netwatch` (uid 1000), which the backend runs as, so a
-  host directory bind-mounted at `/data` ends up owned by uid 1000
+  volume. The backend runs as user `netwatch` (uid 1000), so a directory
+  bind-mounted at `/data` must be writable by uid 1000
 - Writes buffered reports to disk on `docker stop`, and exits non-zero if nginx
   or the backend exits on its own, so the platform restarts it
 
-## Running under upaas
-
-What the [upaas](https://git.eeqj.de/sneak/upaas) app for netwatch needs:
-
-- **Port:** container port `8080`.
-- **Volume:** container path `/data`; the reports are kept in `/data/reports`.
-- **Environment variables:** none is required. An empty one counts as unset, and
-  one set to a value netwatch cannot use stops the container at start, with the
-  reason in its log.
-    - `PORT`, default `8080`: the container port, from 1 to 65535. `8081` cannot
-      be used: the backend listens on it inside the container
-    - `REPORTS_PER_MINUTE`, default `60`: reports each client address may send a
-      minute
-    - `DATA_DIR_MAX_BYTES`, default `1073741824` (1 GiB): the most room the
-      report files may take
-    - `CORS_ALLOWED_ORIGINS`, default empty: other origins whose pages may call
-      the API
-    - `DEBUG`, default `false`: debug logging
-    - `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 a part of the path that exists, `/data`
-      included, is a symbolic link
-    - `TRUSTED_PROXIES`, default empty: set it to the address the reverse proxy
-      in front of the container connects from, as an IP address or CIDR; several
-      are separated by commas. nginx takes the client address from
-      `X-Forwarded-For` only on a request from one of them, and the rate limit
-      counts that address. Unset, `X-Forwarded-For` is ignored and every client
-      behind the proxy shares the proxy's one allowance of `REPORTS_PER_MINUTE`.
-      Name only addresses nothing but the proxy connects from: any client that
-      connects from one can write its own `X-Forwarded-For`, and through a port
-      Docker publishes, every client may connect from the Docker network's
-      gateway, such as `172.17.0.1`.
-- **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
-  seconds after a deploy and fails the deploy unless it is `healthy`. The
-  container also stops when either process exits.
-
 ## Browser Compatibility
 
 Requires a modern browser with ES modules, Fetch API, Canvas API, and CSS custom

TODO.md

@@ -23,93 +23,6 @@ latest run passes.
 
 # Completed Steps
 
-- 2026-09-29: `bin/entrypoint.sh` checks `DATA_DIR` in full before it acts on it
-  as root (issue #80): `DATA_DIR` must be `/data` or a path below it with no
-  `.`, `..` or empty part, and no part of it that exists, `/data` included, may
-  be a symbolic link; anything else stops the start with a message naming
-  `DATA_DIR`. Only then is `DATA_DIR` created and `/data` given to `netwatch`,
-  so a refused start no longer creates directories outside `/data`, and
-  `DATA_DIR=/etc` no longer gives `/etc` to `netwatch`. The `README.md` section
-  "Running under upaas" says which values are accepted
-- 2026-09-29: the container sets up its own data directory (issue #75):
-  `bin/entrypoint.sh`, still as root, creates `DATA_DIR` if missing and gives it
-  and `/data` to the `netwatch` user with mode 750 before starting the backend
-  as that user, so an empty host directory owned by root, or one holding files
-  from another uid, works with no step on the host. It stops the start instead
-  when a symbolic link is on the path to `DATA_DIR`, since root would change
-  whatever the link points to. The `README.md` first-run step that created and
-  chowned the host directory is gone, and the image no longer sets that
-  ownership at build time
-- 2026-09-29: CI can no longer pass on checks that did not run (issue #37):
-  `script/cibuild` is now the org model, byte for byte. It runs
-  `script/bootstrap` and `script/check`, then builds the image with `--no-cache`
-  and the version from `git describe` as the `VERSION` build argument, where it
-  used to be a plain `docker build .` whose check steps could come from the
-  build cache. The workflow puts `~/.local/bin`, where bootstrap links what it
-  installs, on the step's `PATH`, and bootstrap now installs its pinned node
-  when the installed one is older than the frontend's dependencies need
-- 2026-09-29: `backend/.golangci.yml` re-vendored from `sneak/prompts` (issue
-  #41): `gomodguard`, deprecated in golangci-lint v2.12.0, is disabled and its
-  successor `gomodguard_v2` enabled with the org block list, so lint runs print
-  no deprecation warning. The new file also turns `depguard` on with its
-  `test-support` rule, which keeps `net/http/httptest` out of non-test code;
-  netwatch adds no entries of its own to that rule. `backend/script/lint` checks
-  the new sha256
-- 2026-09-29: nginx sends the security headers `REPO_POLICIES.md` requires on
-  every response (issue #18), including errors, `/assets/` and what it passes on
-  from the backend, whose own copies it drops so each header goes out once. They
-  live in `security-headers.conf`, which `nginx.conf` includes. The content
-  security policy allows no inline script or style, so the status dot's grey in
-  `src/main.js` is now a class; `connect-src` is `*` because probed hosts
-  redirect to others, and the browser checks each redirect against it
-- 2026-09-29: the request log is bounded (issue #60): the method, URL, protocol,
-  `User-Agent`, `Referer`, request ID (which chi takes from the client's
-  `X-Request-Id` header) and client address it writes are each cut to 128 bytes,
-  the bound the report handler already used, so one request can no longer put
-  about 1 MiB per field into a log line. That bound and its helper now live in
-  the `logger` package, shared by both
-- 2026-09-29: nginx takes the client address from `X-Forwarded-For` only on
-  requests from the reverse proxies named in the container's `TRUSTED_PROXIES`
-  (issue #64), and by default from none, where it trusted every RFC1918 address
-  before, so a client could write a new address on each request and escape the
-  rate limit. `bin/entrypoint.sh` writes one `set_real_ip_from` line per entry
-  into `/etc/nginx/trusted-proxies.conf`, which `nginx.conf` includes, refusing
-  an entry that is not an IP address or CIDR, as `netwatch-server check-cidr`
-  finds; it starts the backend with `TRUSTED_PROXIES=127.0.0.1/32`, since nginx
-  is its only client
-- 2026-09-29: report file names can no longer collide (issue #61): each is
-  `reports-<timestamp>-<number>.jsonl.zst`, where the number goes up by one for
-  each file the server starts to write, so two flushes in the same millisecond,
-  such as a flush for size and the final flush at shutdown, each get a file of
-  their own instead of the second one failing. A failed write uses up its
-  number, leaving a gap if the file could not be created and otherwise a file
-  under that number that may be incomplete.
-- 2026-09-29: ready to run under upaas (issue #59): the image has a
-  `HEALTHCHECK` that requests `/.well-known/healthcheck` through nginx on the
-  port from `PORT`. The backend no longer reads a bad `PORT` as 0 or a bad
-  `DEBUG` as false: those, and a `BIND_ADDRESS` that is not an IP address, stop
-  it from starting with an error naming the variable, as the limits,
-  `CORS_ALLOWED_ORIGINS` and, now by name, `TRUSTED_PROXIES` already did.
-  `bin/entrypoint.sh` also refuses a `PORT` outside 1 to 65535, and `8081`,
-  where the backend listens inside the container, naming `PORT`. `README.md` has
-  a "Running under upaas" section, whose first-run steps create the host
-  directory for `/data` owned by uid 1000; the image does not change its owner
-- 2026-09-29: nginx listens on `PORT` (issue #26), 8080 when unset or empty: the
-  nginx image renders `nginx.conf` as a template at container start, filling in
-  `PORT` and no other variable. `bin/entrypoint.sh` refuses to start when `PORT`
-  is not digits only. `server_tokens off` keeps the nginx version out of
-  responses. `script/frontend-viewport-test` renders the template the same way.
-  Gzip and a `50x.html` error page are not added
-- 2026-09-29: bounded the report endpoint (issue #20): `POST /api/v1/reports`
-  still needs no credentials, but each client address, as resolved through
-  `TRUSTED_PROXIES`, may send `REPORTS_PER_MINUTE` (default 60) reports a
-  minute, counted by `go-chi/httprate`, and past that gets 429 with
-  `Retry-After`; the report files in `DATA_DIR`, counted from start with those
-  already there, may total at most `DATA_DIR_MAX_BYTES` (default 1 GiB), past
-  which reports get 507; and the wildcard CORS is gone: no CORS headers unless
-  `CORS_ALLOWED_ORIGINS` lists origins, and an entry that is not a plain
-  `scheme://host[:port]` origin, `*` included, stops the server from starting.
-  Deleting report files frees room only at the next start; pruning is issue #54
 - 2026-09-28: one container image (issue #52): the root `Dockerfile` builds the
   only image, and `Dockerfile.backend` is gone. nginx serves the frontend on
   port 8080 and proxies `/api/` and `/.well-known/healthcheck` to the backend,
@@ -223,3 +136,9 @@ latest run passes.
   (main always green policy)
 - Decide what to do with untracked resume.sh: commit it, gitignore it, or delete
   it
+- Upstream fix needed in `sneak/prompts`: the org-standard `.golangci.yml`
+  enables `gomodguard`, which golangci-lint v2.12.2 reports as deprecated since
+  v2.12.0 and replaced by `gomodguard_v2`, so every backend lint run prints a
+  deprecation warning. The file is standardized and must never be edited in this
+  repo, so nothing can be done here beyond tracking it — tracked at
+  <https://git.eeqj.de/sneak/netwatch/issues/41>

backend/.golangci.yml

@@ -10,20 +10,14 @@ run:
 
 linters:
   default: all
-  enable:
-    # Successor to the deprecated gomodguard. Named explicitly, rather than
-    # left to `default: all`, because it carries the module policy below.
-    - gomodguard_v2
   disable:
     # Genuinely incompatible with project patterns
     - exhaustruct      # Requires all struct fields
+    - depguard         # Dependency allow/block lists
     - godot            # Requires comments to end with periods
+    - wsl              # Deprecated, replaced by wsl_v5
     - wrapcheck        # Too verbose for internal packages
     - varnamelen       # Short names like db, id are idiomatic Go
-    # Deprecated: the warning is attached to the old name, so it is
-    # silenced by disabling that name, not by enabling the successor.
-    - wsl              # Deprecated, replaced by wsl_v5
-    - gomodguard       # Deprecated, replaced by gomodguard_v2
   settings:
     lll:
       line-length: 88
@@ -34,64 +28,6 @@ linters:
       max-complexity: 15
     dupl:
       threshold: 100
-    depguard:
-      # Test-support code must not be compiled into the shipped binary. A
-      # test-support package exists to hand a test privileges the program
-      # itself must never have, so a file that is not a test must not import
-      # one. Test files, and the files inside a package whose directory name
-      # ends in `test`, are where that code belongs, and are exempt.
-      #
-      # The deny list below is the one part of this file a repository is
-      # expected to extend, and the only part it may. depguard matches an
-      # import path against a list of prefixes, so it cannot be told "any path
-      # whose last segment ends in test"; a repository's own test-support
-      # packages have to be named here one at a time, by full import path,
-      # under a module path that differs from repository to repository. Add
-      # them; change nothing else.
-      rules:
-        test-support:
-          list-mode: lax
-          files:
-            - "$all"
-            - "!$test"
-            - "!**/*test/**"
-          deny:
-            - pkg: net/http/httptest
-              desc: >-
-                Test-support code belongs in test files and in packages whose
-                directory name ends in test, not in the shipped binary.
-    # Only decisions already recorded in the Go package defaults are
-    # listed here. Every entry matches the module path exactly.
-    gomodguard_v2:
-      blocked:
-        - module: github.com/rs/zerolog
-          recommendations:
-            - log/slog
-          reason: "Structured logging is stdlib log/slog."
-        # One entry per pre-fork module path, because the later releases
-        # are separate paths. A prefix match would be shorter but would
-        # also reach github.com/go-redis/redismock, the test double for
-        # the successor these entries recommend.
-        - module: github.com/go-redis/redis
-          recommendations:
-            - github.com/redis/go-redis/v9
-          reason: "Pre-fork module; use the maintained go-redis v9."
-        - module: github.com/go-redis/redis/v7
-          recommendations:
-            - github.com/redis/go-redis/v9
-          reason: "Pre-fork module; use the maintained go-redis v9."
-        - module: github.com/go-redis/redis/v8
-          recommendations:
-            - github.com/redis/go-redis/v9
-          reason: "Pre-fork module; use the maintained go-redis v9."
-        - module: github.com/sergi/go-diff
-          recommendations:
-            - github.com/aymanbagabas/go-udiff
-          reason: "No unified diff output; use go-udiff."
-        - module: github.com/hexops/gotextdiff
-          recommendations:
-            - github.com/aymanbagabas/go-udiff
-          reason: "Unmaintained fork; use go-udiff."
 
 issues:
   max-issues-per-linter: 0

backend/README.md

@@ -75,26 +75,18 @@ Internal packages in `internal/` follow standard Go project layout:
 
 ### Configuration
 
-| Variable               | Default              | Description                                                                                              |
-| ---------------------- | -------------------- | -------------------------------------------------------------------------------------------------------- |
-| `BIND_ADDRESS`         | empty                | IP address to listen on; empty listens on every interface                                                |
-| `PORT`                 | `8080`               | HTTP listen port                                                                                         |
-| `DATA_DIR`             | `./data/reports`     | Directory for compressed reports                                                                         |
-| `DATA_DIR_MAX_BYTES`   | `1073741824` (1 GiB) | Largest total size of the report files in `DATA_DIR`; see [Report limits](#report-limits)                |
-| `DEBUG`                | `false`              | Enable debug logging                                                                                     |
-| `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)                                  |
+| Variable          | Default              | Description                                                                                              |
+| ----------------- | -------------------- | -------------------------------------------------------------------------------------------------------- |
+| `BIND_ADDRESS`    | empty                | IP address to listen on; empty listens on every interface                                                |
+| `PORT`            | `8080`               | HTTP listen port                                                                                         |
+| `DATA_DIR`        | `./data/reports`     | Directory for compressed reports                                                                         |
+| `DEBUG`           | `false`              | Enable debug logging                                                                                     |
+| `TRUSTED_PROXIES` | loopback + RFC1918   | Comma-separated CIDRs whose `X-Forwarded-For` / `X-Real-IP` headers are trusted for client IP resolution |
 
 `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`.
-The loopback entries cover a reverse proxy on the same host. A request whose
-direct peer is outside this set has its forwarded headers ignored, and the
-direct peer is logged and rate-limited instead. The container image does not use
-this default; 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
-starting, with an error naming the variable. An empty variable counts as unset.
+The loopback entries cover the reverse proxy that shares the container; the
+RFC1918 ranges match `nginx.conf`. A request whose direct peer is outside this
+set has its forwarded headers ignored, and the direct peer is logged instead.
 
 ### Container image
 
@@ -102,68 +94,14 @@ The root `Dockerfile` builds one image in which nginx listens on the public port
 8080, serves the frontend, and proxies `/api/` and `/.well-known/healthcheck` to
 this server. The image's entrypoint, `bin/entrypoint.sh`, starts the server as
 user `netwatch` (uid 1000) with `BIND_ADDRESS=127.0.0.1` and `PORT=8081`, so
-only nginx reaches it, and with `TRUSTED_PROXIES=127.0.0.1/32`, so it takes the
-client address nginx passes on and no other. `DATA_DIR` is `/data/reports`, on
-the `/data` volume; the entrypoint creates it and gives it and `/data` to
-`netwatch` before starting the server. nginx replaces the security headers
-this server sets with those in the root `security-headers.conf`, so those are
-what clients of the image see.
-
-The container's own `TRUSTED_PROXIES` goes to nginx instead: IP addresses or
-CIDRs, separated by commas, of the reverse proxies in front of the container.
-nginx takes the client address from `X-Forwarded-For` only on a request from one
-of them. Unset or empty, nginx trusts no proxy, and the client address is the
-one each request comes from, so every client behind a proxy shares one rate
-limit. An entry that is not an IP address or CIDR, such as a hostname or
-`1.2.3`, stops the container at start with an error naming `TRUSTED_PROXIES`:
-the entrypoint checks each entry with `netwatch-server check-cidr`, which parses
-it as this server parses its own `TRUSTED_PROXIES`.
+only nginx reaches it. `DATA_DIR` is `/data/reports`, on the `/data` volume,
+which `netwatch` owns.
 
 ### Report storage
 
-Reports are written as `reports-<timestamp>-<number>.jsonl.zst` files in
-`DATA_DIR`. The timestamp is in UTC to the millisecond, so the names sort by
-time. The number starts at 1 when the server starts and goes up by one for each
-file the server starts to write, so two files written in the same millisecond
-still get different names. A failed write uses up its number, leaving a gap in
-the numbers if the file could not be created and otherwise a file under that
-number that may be incomplete. Each file contains one JSON object per line,
-compressed with zstd. Files are created with `O_EXCL` to prevent overwrites.
-
-### Report limits
-
-`POST /api/v1/reports` takes reports from anyone who can reach it, without
-credentials, so it is bounded instead. Both refusals below answer with the same
-`{"status":"error"}` body as any other error.
-
-- **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
-  count, fading out over the current one, so an address is sure never to be
-  refused only while it sends at most half of `REPORTS_PER_MINUTE` in any 60
-  seconds. The page sends one report a minute from each open tab, so the default
-  of 60 refuses nothing from up to 30 tabs behind one address, such as a
-  household or an office sharing it, however their reports bunch up. Report
-  responses also carry `X-RateLimit-Limit`, `X-RateLimit-Remaining` and
-  `X-RateLimit-Reset` headers.
-- **Size cap.** The report files in `DATA_DIR` may total at most
-  `DATA_DIR_MAX_BYTES`, counting the files already there at start. Reports
-  waiting in memory count at their uncompressed size until they are written, so
-  a report that would take the total past the cap is refused with 507, and
-  nothing of it is stored. Deleting report files frees room only at the next
-  start, when the files are counted again. The default of 1 GiB is small enough
-  for any host; set it to the space you can give `DATA_DIR`.
-
-### CORS
-
-The page calls the API from the origin it is served from, so by default the
-server sends no CORS headers, and browsers let no other origin's pages call it.
-To serve the page from elsewhere, list that origin in `CORS_ALLOWED_ORIGINS`
-(for example `https://netwatch.example.com`); pages from a listed origin may
-`GET` and `POST` with a `Content-Type` header. Each entry must be a plain
-origin, `scheme://host` with an optional `:port`, as browsers send it: no path,
-not even a trailing `/`, and no `*`. Any other entry stops the server from
-starting, with an error naming `CORS_ALLOWED_ORIGINS`.
+Reports are written as `reports-<timestamp>.jsonl.zst` files in `DATA_DIR`.
+Each file contains one JSON object per line, compressed with zstd. Files are
+created with `O_EXCL` to prevent overwrites.
 
 ## TODO
 

backend/cmd/netwatch-server/main.go

@@ -2,9 +2,6 @@
 package main
 
 import (
-	"fmt"
-	"os"
-
 	"sneak.berlin/go/netwatch/internal/config"
 	"sneak.berlin/go/netwatch/internal/globals"
 	"sneak.berlin/go/netwatch/internal/handlers"
@@ -25,19 +22,6 @@ var (
 )
 
 func main() {
-	// "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
-	}
-
 	globals.Appname = Appname
 	globals.Version = Version
 	globals.Buildarch = Buildarch

backend/go.mod

@@ -5,7 +5,6 @@ go 1.25.5
 require (
 	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
 	github.com/joho/godotenv v1.5.1
 	github.com/klauspost/compress v1.18.4
 	github.com/spf13/viper v1.21.0
@@ -15,7 +14,6 @@ require (
 require (
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
 	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
-	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
 	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
 	github.com/sagikazarmark/locafero v0.11.0 // indirect
 	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
@@ -23,11 +21,10 @@ require (
 	github.com/spf13/cast v1.10.0 // indirect
 	github.com/spf13/pflag v1.0.10 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
-	github.com/zeebo/xxh3 v1.0.2 // indirect
 	go.uber.org/dig v1.19.0 // indirect
 	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 v0.30.0 // indirect
+	golang.org/x/sys v0.29.0 // indirect
 	golang.org/x/text v0.28.0 // indirect
 )

backend/go.sum

@@ -8,8 +8,6 @@ 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-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 v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
@@ -18,8 +16,6 @@ github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 github.com/klauspost/compress v1.18.4 h1:RPhnKRAQ4Fh8zU2FY/6ZFDwTVTxgJ/EMydqSTzE9a2c=
 github.com/klauspost/compress v1.18.4/go.mod h1:R0h/fSBs8DE4ENlcrlib3PsXS61voFxhIs2DeRhCvJ4=
-github.com/klauspost/cpuid/v2 v2.2.10 h1:tBs3QSyvjDyFTq3uoc/9xFpCuOsJQFNPiAhYdw2skhE=
-github.com/klauspost/cpuid/v2 v2.2.10/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -46,10 +42,6 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
-github.com/zeebo/assert v1.3.0 h1:g7C04CbJuIDKNPFHmsk4hwZDO5O+kntRxzaUoNXj+IQ=
-github.com/zeebo/assert v1.3.0/go.mod h1:Pq9JiuJQpG8JLJdtkwrJESF0Foym2/D9XMU5ciN/wJ0=
-github.com/zeebo/xxh3 v1.0.2 h1:xZmwmqxHZA8AI603jOQ0tMqmBr9lPeFwGg6d+xy9DC0=
-github.com/zeebo/xxh3 v1.0.2/go.mod h1:5NWz9Sef7zIDm2JHfFlcQvNekmcEl9ekUZQQKCYaDcA=
 go.uber.org/dig v1.19.0 h1:BACLhebsYdpQ7IROQ1AGPjrXcP5dF80U3gKoFzbaq/4=
 go.uber.org/dig v1.19.0/go.mod h1:Us0rSJiThwCv2GteUN0Q7OKvU7n5J4dxZ9JKUXozFdE=
 go.uber.org/fx v1.24.0 h1:wE8mruvpg2kiiL1Vqd0CC+tr0/24XIB10Iwp2lLWzkg=
@@ -62,8 +54,8 @@ go.uber.org/zap v1.26.0 h1:sI7k6L95XOKS281NhVKOFCUNIvv9e0w4BF8N3u+tCRo=
 go.uber.org/zap v1.26.0/go.mod h1:dtElttAiwGvoJ/vj4IwHBS/gXsEu/pZ50mUIRWuG0so=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
-golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
 golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

backend/internal/config/config.go

@@ -4,12 +4,7 @@ package config
 
 import (
 	"errors"
-	"fmt"
 	"log/slog"
-	"math"
-	"net/netip"
-	"net/url"
-	"strconv"
 	"strings"
 
 	"sneak.berlin/go/netwatch/internal/globals"
@@ -21,31 +16,13 @@ import (
 )
 
 // defaultTrustedProxies lists the networks whose forwarded
-// headers are honoured by default: IPv4 and IPv6 loopback,
-// 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.
+// headers are honoured by default. It covers the RFC1918
+// ranges (to match nginx.conf) plus IPv4 and IPv6 loopback,
+// because the reverse proxy shares the container and reaches
+// the backend over loopback.
 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; backend/README.md gives the
-// reasons for these values.
-const (
-	defaultReportsPerMinute = 60
-	defaultDataDirMaxBytes  = 1 << 30 // 1 GiB
-)
-
-var (
-	errNotPositive = errors.New("must be a positive whole number")
-	errNotOrigin   = errors.New(
-		"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")
-)
-
 // Params defines the dependencies for Config.
 type Params struct {
 	fx.In
@@ -56,24 +33,20 @@ type Params struct {
 
 // Config holds the resolved application configuration.
 type Config struct {
-	BindAddress        string
-	CORSAllowedOrigins []string
-	DataDir            string
-	DataDirMaxBytes    int64
-	Debug              bool
-	MetricsPassword    string
-	MetricsUsername    string
-	Port               int
-	ReportsPerMinute   int
-	SentryDSN          string
-	TrustedProxies     []string
-	log                *slog.Logger
-	params             *Params
+	BindAddress     string
+	DataDir         string
+	Debug           bool
+	MetricsPassword string
+	MetricsUsername string
+	Port            int
+	SentryDSN       string
+	TrustedProxies  []string
+	log             *slog.Logger
+	params          *Params
 }
 
 // New loads configuration from env, .env files, and config
-// files, returning a fully resolved Config. It fails, with an error
-// naming the setting, on a value the server cannot use.
+// files, returning a fully resolved Config.
 func New(
 	_ fx.Lifecycle,
 	params Params,
@@ -88,15 +61,11 @@ func New(
 
 	viper.AutomaticEnv()
 
-	// An empty CORS_ALLOWED_ORIGINS allows no other origin.
-	viper.SetDefault("CORS_ALLOWED_ORIGINS", "")
 	viper.SetDefault("DATA_DIR", "./data/reports")
-	viper.SetDefault("DATA_DIR_MAX_BYTES", defaultDataDirMaxBytes)
 	viper.SetDefault("DEBUG", "false")
 	// An empty BIND_ADDRESS listens on every interface.
 	viper.SetDefault("BIND_ADDRESS", "")
 	viper.SetDefault("PORT", "8080")
-	viper.SetDefault("REPORTS_PER_MINUTE", defaultReportsPerMinute)
 	viper.SetDefault("SENTRY_DSN", "")
 	viper.SetDefault("METRICS_USERNAME", "")
 	viper.SetDefault("METRICS_PASSWORD", "")
@@ -111,39 +80,17 @@ func New(
 		}
 	}
 
-	// Read with strconv: viper's GetInt and GetBool would read a value
-	// 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)
-	}
-
-	debug, err := strconv.ParseBool(viper.GetString("DEBUG"))
-	if err != nil {
-		return nil, fmt.Errorf("DEBUG %q: %w",
-			viper.GetString("DEBUG"), errNotBool)
-	}
-
 	s := &Config{
-		BindAddress:        viper.GetString("BIND_ADDRESS"),
-		CORSAllowedOrigins: splitList(viper.GetString("CORS_ALLOWED_ORIGINS")),
-		DataDir:            viper.GetString("DATA_DIR"),
-		DataDirMaxBytes:    viper.GetInt64("DATA_DIR_MAX_BYTES"),
-		Debug:              debug,
-		MetricsPassword:    viper.GetString("METRICS_PASSWORD"),
-		MetricsUsername:    viper.GetString("METRICS_USERNAME"),
-		Port:               port,
-		ReportsPerMinute:   viper.GetInt("REPORTS_PER_MINUTE"),
-		SentryDSN:          viper.GetString("SENTRY_DSN"),
-		TrustedProxies:     splitList(viper.GetString("TRUSTED_PROXIES")),
-		log:                log,
-		params:             &params,
-	}
-
-	err = s.check()
-	if err != nil {
-		return nil, err
+		BindAddress:     viper.GetString("BIND_ADDRESS"),
+		DataDir:         viper.GetString("DATA_DIR"),
+		Debug:           viper.GetBool("DEBUG"),
+		MetricsPassword: viper.GetString("METRICS_PASSWORD"),
+		MetricsUsername: viper.GetString("METRICS_USERNAME"),
+		Port:            viper.GetInt("PORT"),
+		SentryDSN:       viper.GetString("SENTRY_DSN"),
+		TrustedProxies:  splitList(viper.GetString("TRUSTED_PROXIES")),
+		log:             log,
+		params:          &params,
 	}
 
 	if s.Debug {
@@ -154,51 +101,6 @@ func New(
 	return s, nil
 }
 
-// check fails with an error naming the first setting here whose value
-// the server cannot use. New checks PORT and DEBUG as it reads them,
-// 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.
-	if s.ReportsPerMinute <= 0 {
-		return fmt.Errorf("REPORTS_PER_MINUTE %q: %w",
-			viper.GetString("REPORTS_PER_MINUTE"), errNotPositive)
-	}
-
-	if s.DataDirMaxBytes <= 0 {
-		return fmt.Errorf("DATA_DIR_MAX_BYTES %q: %w",
-			viper.GetString("DATA_DIR_MAX_BYTES"), errNotPositive)
-	}
-
-	if s.BindAddress != "" {
-		_, err := netip.ParseAddr(s.BindAddress)
-		if err != nil {
-			return fmt.Errorf("BIND_ADDRESS %q: %w", s.BindAddress, errNotIP)
-		}
-	}
-
-	return checkOrigins(s.CORSAllowedOrigins)
-}
-
-// checkOrigins fails on the first CORS_ALLOWED_ORIGINS entry that is
-// not a plain origin, scheme://host with an optional port, as browsers
-// send it; anything more, such as a trailing "/", would match no page.
-// go-chi/cors reads a "*" anywhere in an entry as a wildcard, so no
-// entry may contain one.
-func checkOrigins(origins []string) error {
-	for _, origin := range origins {
-		u, err := url.Parse(origin)
-		if err != nil || u.Scheme == "" || u.Host == "" ||
-			strings.Contains(origin, "*") ||
-			origin != u.Scheme+"://"+u.Host {
-			return fmt.Errorf("CORS_ALLOWED_ORIGINS %q: %w",
-				origin, errNotOrigin)
-		}
-	}
-
-	return nil
-}
-
 // splitList turns a comma-separated setting into a trimmed
 // slice, dropping empty entries.
 func splitList(raw string) []string {

backend/internal/config/config_test.go

@@ -1,121 +0,0 @@
-package config_test
-
-import (
-	"strings"
-	"testing"
-
-	"sneak.berlin/go/netwatch/internal/config"
-	"sneak.berlin/go/netwatch/internal/globals"
-	"sneak.berlin/go/netwatch/internal/logger"
-
-	"go.uber.org/fx"
-)
-
-// requireConfigError builds the config as main does and fails the
-// 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()
-
-	app := fx.New(
-		fx.NopLogger,
-		fx.Provide(globals.New, logger.New, config.New),
-		fx.Invoke(func(*config.Config) {}),
-	)
-
-	err := app.Err()
-	if err == nil || !strings.Contains(err.Error(), setting) {
-		t.Fatalf("config error = %v, want one naming %s", err, setting)
-	}
-}
-
-// TestSettingsLoadAsGiven: valid values pass the checks and are used
-// as given. bin/entrypoint.sh starts the server with these
-// BIND_ADDRESS and PORT values.
-func TestSettingsLoadAsGiven(t *testing.T) {
-	t.Setenv("BIND_ADDRESS", "127.0.0.1")
-	t.Setenv("PORT", "8081")
-	t.Setenv("DEBUG", "true")
-
-	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.BindAddress != "127.0.0.1" || cfg.Port != 8081 || !cfg.Debug {
-		t.Fatalf("BindAddress, Port, Debug = %q, %d, %t; "+
-			"want \"127.0.0.1\", 8081, true",
-			cfg.BindAddress, cfg.Port, cfg.Debug)
-	}
-}
-
-// TestPortMustBeAPortNumber: viper reads a value that is not a number
-// as 0, on which the server would listen on a random port.
-func TestPortMustBeAPortNumber(t *testing.T) {
-	for _, value := range []string{"abc", "0", "65536", "8080.5"} {
-		t.Run(value, func(t *testing.T) {
-			t.Setenv("PORT", value)
-
-			requireConfigError(t, "PORT")
-		})
-	}
-}
-
-// TestDebugMustBeTrueOrFalse: viper reads any other value, such as
-// "yes", as false.
-func TestDebugMustBeTrueOrFalse(t *testing.T) {
-	t.Setenv("DEBUG", "yes")
-
-	requireConfigError(t, "DEBUG")
-}
-
-// TestBindAddressMustBeAnIPAddress: a host name would be looked up
-// only once the server starts listening, and a mistyped one would stop
-// it then with an error that does not name the setting.
-func TestBindAddressMustBeAnIPAddress(t *testing.T) {
-	t.Setenv("BIND_ADDRESS", "localhost")
-
-	requireConfigError(t, "BIND_ADDRESS")
-}
-
-// TestReportsPerMinuteMustBePositive: unchecked, zero would panic
-// when the routes are built, and a negative rate would lift the
-// limit.
-func TestReportsPerMinuteMustBePositive(t *testing.T) {
-	t.Setenv("REPORTS_PER_MINUTE", "0")
-
-	requireConfigError(t, "REPORTS_PER_MINUTE")
-}
-
-// TestDataDirMaxBytesMustBeANumber: viper reads a value that is not
-// a number, such as "1GB", as 0, which would refuse every report.
-func TestDataDirMaxBytesMustBeANumber(t *testing.T) {
-	t.Setenv("DATA_DIR_MAX_BYTES", "1GB")
-
-	requireConfigError(t, "DATA_DIR_MAX_BYTES")
-}
-
-// TestCORSAllowedOriginsMustBeOrigins: "*" would let every origin in,
-// and an entry that is not a plain origin would match no page.
-func TestCORSAllowedOriginsMustBeOrigins(t *testing.T) {
-	for _, entry := range []string{
-		"*",
-		"https://*.netwatch.example",
-		"netwatch.example",
-		"https://netwatch.example/",
-	} {
-		t.Run(entry, func(t *testing.T) {
-			t.Setenv("CORS_ALLOWED_ORIGINS", entry)
-
-			requireConfigError(t, "CORS_ALLOWED_ORIGINS")
-		})
-	}
-}

backend/internal/handlers/export_test.go

@@ -2,6 +2,9 @@ package handlers
 
 import "log/slog"
 
+// MaxLoggedFieldBytes exposes the log bound to the external tests.
+const MaxLoggedFieldBytes = maxLoggedFieldBytes
+
 // NewForTest builds a Handlers around a report sink and logger,
 // bypassing the fx graph so handler behaviour (including the
 // storage failure path) is exercisable in unit tests.

backend/internal/handlers/report.go

@@ -4,11 +4,13 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
-
-	"sneak.berlin/go/netwatch/internal/logger"
-	"sneak.berlin/go/netwatch/internal/reportbuf"
 )
 
+// maxLoggedFieldBytes bounds untrusted text (string fields,
+// decode error text) before it is logged, so a caller cannot
+// inflate log volume with an oversized value.
+const maxLoggedFieldBytes = 128
+
 type reportSample struct {
 	T       int64   `json:"t"`
 	Latency *int    `json:"latency"`
@@ -53,9 +55,10 @@ func (s *Handlers) HandleReport() http.HandlerFunc {
 
 		err = s.buf.Append(rpt)
 		if err != nil {
+			s.log.Error("failed to buffer report", "error", err)
 			s.respondJSON(w, r,
 				&response{Status: "error"},
-				s.appendErrorStatus(err),
+				http.StatusInternalServerError,
 			)
 
 			return
@@ -79,27 +82,12 @@ func (s *Handlers) decodeErrorStatus(err error) int {
 	// The decoder's error text can quote request bytes (a whole
 	// oversized number, for example), so it is bounded too.
 	s.log.Error("failed to decode report",
-		"error", logger.BoundedForLog(err.Error()),
+		"error", boundedForLog(err.Error()),
 	)
 
 	return http.StatusBadRequest
 }
 
-// appendErrorStatus logs a failure to store a report and returns
-// the status to send: 507 when the report files are at their size
-// cap, otherwise 500.
-func (s *Handlers) appendErrorStatus(err error) int {
-	if errors.Is(err, reportbuf.ErrFull) {
-		s.log.Warn("report refused: report files at their size cap")
-
-		return http.StatusInsufficientStorage
-	}
-
-	s.log.Error("failed to buffer report", "error", err)
-
-	return http.StatusInternalServerError
-}
-
 // logReportReceived logs an accepted report. Untrusted fields are
 // bounded (client_id, timestamp) or reduced to a length
 // (geo_bytes) so the raw attacker-controlled body never reaches
@@ -111,10 +99,20 @@ func (s *Handlers) logReportReceived(rpt report) {
 	}
 
 	s.log.Info("report received",
-		"client_id", logger.BoundedForLog(rpt.ClientID),
-		"timestamp", logger.BoundedForLog(rpt.Timestamp),
+		"client_id", boundedForLog(rpt.ClientID),
+		"timestamp", boundedForLog(rpt.Timestamp),
 		"host_count", len(rpt.Hosts),
 		"total_samples", totalSamples,
 		"geo_bytes", len(rpt.Geo),
 	)
 }
+
+// boundedForLog truncates an untrusted string to a fixed byte
+// bound so an attacker-controlled field cannot dominate the log.
+func boundedForLog(s string) string {
+	if len(s) > maxLoggedFieldBytes {
+		return s[:maxLoggedFieldBytes]
+	}
+
+	return s
+}

backend/internal/handlers/report_test.go

@@ -12,9 +12,7 @@ import (
 	"testing"
 
 	"sneak.berlin/go/netwatch/internal/handlers"
-	"sneak.berlin/go/netwatch/internal/logger"
 	"sneak.berlin/go/netwatch/internal/middleware"
-	"sneak.berlin/go/netwatch/internal/reportbuf"
 )
 
 var errStorageFailed = errors.New("storage failed")
@@ -68,32 +66,6 @@ func TestHandleReportStorageFailureIsNon2xx(t *testing.T) {
 	}
 }
 
-// TestHandleReportFullIs507 checks the answer when the report files
-// are at their size cap: 507 and the usual error body, which tells
-// the client nothing more.
-func TestHandleReportFullIs507(t *testing.T) {
-	t.Parallel()
-
-	h := newTestHandlers(stubAppender{err: reportbuf.ErrFull}, io.Discard)
-
-	rec := httptest.NewRecorder()
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodPost, "/api/v1/reports",
-		strings.NewReader(`{"clientId":"c1","hosts":[]}`),
-	)
-
-	h.HandleReport().ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusInsufficientStorage {
-		t.Fatalf("status = %d, want %d",
-			rec.Code, http.StatusInsufficientStorage)
-	}
-
-	if got := rec.Body.String(); got != "{\"status\":\"error\"}\n" {
-		t.Errorf("body = %q, want %q", got, "{\"status\":\"error\"}\n")
-	}
-}
-
 func TestHandleReportMalformedJSONIs400(t *testing.T) {
 	t.Parallel()
 
@@ -175,7 +147,7 @@ func TestHandleReportDoesNotLogRawGeo(t *testing.T) {
 func TestHandleReportLogsClientIDCutToBound(t *testing.T) {
 	t.Parallel()
 
-	long := strings.Repeat("c", 2*logger.MaxLoggedFieldBytes)
+	long := strings.Repeat("c", 2*handlers.MaxLoggedFieldBytes)
 
 	var logbuf bytes.Buffer
 
@@ -198,16 +170,16 @@ func TestHandleReportLogsClientIDCutToBound(t *testing.T) {
 		t.Fatalf("log line not JSON: %v (%q)", err, logbuf.String())
 	}
 
-	want := long[:logger.MaxLoggedFieldBytes]
+	want := long[:handlers.MaxLoggedFieldBytes]
 
 	if logged["client_id"] != want {
 		t.Fatalf("logged client_id not cut to %d bytes: %q",
-			logger.MaxLoggedFieldBytes, logged["client_id"])
+			handlers.MaxLoggedFieldBytes, logged["client_id"])
 	}
 
 	if logged["timestamp"] != want {
 		t.Fatalf("logged timestamp not cut to %d bytes: %q",
-			logger.MaxLoggedFieldBytes, logged["timestamp"])
+			handlers.MaxLoggedFieldBytes, logged["timestamp"])
 	}
 }
 
@@ -216,7 +188,7 @@ func TestHandleReportDecodeErrorLogIsBounded(t *testing.T) {
 
 	// A number too large for its int64 field makes the decoder's
 	// error text quote the whole number.
-	huge := strings.Repeat("9", 2*logger.MaxLoggedFieldBytes)
+	huge := strings.Repeat("9", 2*handlers.MaxLoggedFieldBytes)
 
 	var logbuf bytes.Buffer
 

backend/internal/logger/logger.go

@@ -11,21 +11,6 @@ import (
 	"go.uber.org/fx"
 )
 
-// MaxLoggedFieldBytes bounds untrusted text (request fields,
-// header values, decode error text) before it is logged, so a
-// caller cannot inflate log volume with an oversized value.
-const MaxLoggedFieldBytes = 128
-
-// BoundedForLog truncates an untrusted string to a fixed byte
-// bound so an attacker-controlled field cannot dominate the log.
-func BoundedForLog(s string) string {
-	if len(s) > MaxLoggedFieldBytes {
-		return s[:MaxLoggedFieldBytes]
-	}
-
-	return s
-}
-
 // Params defines the dependencies for Logger.
 type Params struct {
 	fx.In

backend/internal/middleware/export_test.go

@@ -15,13 +15,6 @@ func NewWithLogger(log *slog.Logger) *Middleware {
 	return &Middleware{log: log}
 }
 
-// NewWithTrustedProxies builds a Middleware that honours forwarded
-// headers from the given networks, for tests of the client address
-// paths without the fx graph.
-func NewWithTrustedProxies(trusted []netip.Prefix) *Middleware {
-	return &Middleware{trustedProxies: trusted}
-}
-
 func ClientIP(
 	remoteAddr string,
 	header http.Header,
@@ -29,3 +22,7 @@ func ClientIP(
 ) string {
 	return clientIP(remoteAddr, header, trusted)
 }
+
+func ParseTrustedProxies(cidrs []string) ([]netip.Prefix, error) {
+	return parseTrustedProxies(cidrs)
+}

backend/internal/middleware/middleware.go

@@ -20,7 +20,6 @@ import (
 
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/go-chi/cors"
-	"github.com/go-chi/httprate"
 	"go.uber.org/fx"
 )
 
@@ -64,7 +63,7 @@ func New(
 	_ fx.Lifecycle,
 	params Params,
 ) (*Middleware, error) {
-	trusted, err := ParseTrustedProxies(params.Config.TrustedProxies)
+	trusted, err := parseTrustedProxies(params.Config.TrustedProxies)
 	if err != nil {
 		return nil, err
 	}
@@ -77,18 +76,16 @@ func New(
 	return s, nil
 }
 
-// ParseTrustedProxies converts the TRUSTED_PROXIES entries into
-// prefixes, failing fast on any malformed entry. Each entry must be
-// a CIDR; a lone address is refused. "netwatch-server check-cidr"
-// runs it too.
-func ParseTrustedProxies(cidrs []string) ([]netip.Prefix, error) {
+// parseTrustedProxies converts CIDR strings into prefixes,
+// failing fast on any malformed entry.
+func parseTrustedProxies(cidrs []string) ([]netip.Prefix, error) {
 	prefixes := make([]netip.Prefix, 0, len(cidrs))
 
 	for _, cidr := range cidrs {
 		prefix, err := netip.ParsePrefix(cidr)
 		if err != nil {
 			return nil, fmt.Errorf(
-				"TRUSTED_PROXIES %q: %w", cidr, err,
+				"trusted proxy %q: %w", cidr, err,
 			)
 		}
 
@@ -189,10 +186,7 @@ func addrInAny(s string, trusted []netip.Prefix) bool {
 }
 
 // Logging returns middleware that logs each request with
-// timing, status code, and client information. Every string
-// taken from the request is cut to logger.MaxLoggedFieldBytes,
-// including the request ID, which chi takes from the client's
-// X-Request-Id header when one is sent.
+// timing, status code, and client information.
 func (s *Middleware) Logging() func(http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(
@@ -205,19 +199,21 @@ func (s *Middleware) Logging() func(http.Handler) http.Handler {
 					latency := time.Since(start)
 					s.log.InfoContext(ctx, "request",
 						"request_start", start,
-						"method", logger.BoundedForLog(r.Method),
-						"url", logger.BoundedForLog(r.URL.String()),
-						"useragent", logger.BoundedForLog(r.UserAgent()),
+						"method", r.Method,
+						"url", r.URL.String(),
+						"useragent", r.UserAgent(),
 						"request_id",
-						logger.BoundedForLog(middleware.GetReqID(ctx)),
-						"referer", logger.BoundedForLog(r.Referer()),
-						"proto", logger.BoundedForLog(r.Proto),
+						ctx.Value(
+							middleware.RequestIDKey,
+						),
+						"referer", r.Referer(),
+						"proto", r.Proto,
 						"remote_ip",
-						logger.BoundedForLog(clientIP(
+						clientIP(
 							r.RemoteAddr,
 							r.Header,
 							s.trustedProxies,
-						)),
+						),
 						"status", lrw.statusCode,
 						"latency_ms",
 						latency.Milliseconds(),
@@ -324,43 +320,21 @@ func (s *Middleware) Recoverer() func(http.Handler) http.Handler {
 	}
 }
 
-// CORS returns middleware that lets pages served from the given
-// origins call the API. With no origins it adds no CORS headers at
-// all, so only same-origin pages can use the API. That case must not
-// reach cors.Handler, which treats an empty origin list as "allow
-// every origin".
-func (s *Middleware) CORS(
-	origins []string,
-) func(http.Handler) http.Handler {
-	if len(origins) == 0 {
-		return func(next http.Handler) http.Handler { return next }
-	}
-
+// CORS returns middleware that adds permissive CORS headers.
+func (s *Middleware) CORS() func(http.Handler) http.Handler {
 	return cors.Handler(cors.Options{
-		AllowedOrigins:   origins,
-		AllowedMethods:   []string{http.MethodGet, http.MethodPost},
-		AllowedHeaders:   []string{"Content-Type"},
+		AllowedOrigins: []string{"*"},
+		AllowedMethods: []string{
+			"GET", "POST", "PUT", "DELETE", "OPTIONS",
+		},
+		AllowedHeaders: []string{
+			"Accept",
+			"Authorization",
+			"Content-Type",
+			"X-CSRF-Token",
+		},
+		ExposedHeaders:   []string{"Link"},
 		AllowCredentials: false,
 		MaxAge:           corsMaxAgeSec,
 	})
 }
-
-// RateLimit returns middleware that allows each client address
-// perMinute requests a minute and answers the rest with 429, the
-// Retry-After header httprate sets, and the usual error body. The
-// address is the one clientIP resolves, so clients behind the reverse
-// proxy are limited one by one, not together as the proxy.
-func (s *Middleware) RateLimit(
-	perMinute int,
-) func(http.Handler) http.Handler {
-	return httprate.LimitBy(perMinute, time.Minute,
-		func(r *http.Request) (string, error) {
-			return clientIP(r.RemoteAddr, r.Header, s.trustedProxies), nil
-		},
-		httprate.WithLimitHandler(
-			func(w http.ResponseWriter, _ *http.Request) {
-				writeJSONError(w, http.StatusTooManyRequests)
-			},
-		),
-	)
-}

backend/internal/middleware/middleware_test.go

@@ -10,13 +10,8 @@ import (
 	"net/netip"
 	"strings"
 	"testing"
-	"testing/synctest"
-	"time"
 
-	"sneak.berlin/go/netwatch/internal/logger"
 	"sneak.berlin/go/netwatch/internal/middleware"
-
-	chimiddleware "github.com/go-chi/chi/v5/middleware"
 )
 
 const (
@@ -39,32 +34,15 @@ func mustPrefixes(t *testing.T, cidrs ...string) []netip.Prefix {
 	return prefixes
 }
 
-// TestParseTrustedProxiesRejectsMalformed includes entries nginx would
-// read as another address or look up as a hostname, in the CIDR form
-// bin/entrypoint.sh gives "netwatch-server check-cidr".
 func TestParseTrustedProxiesRejectsMalformed(t *testing.T) {
 	t.Parallel()
 
-	for _, cidr := range []string{
-		"not-a-cidr", "10.0.0.1", "1.2.3/32", "172.30/32", "10/32",
-		"cafe/32", "999.1.1.1/32", "10.0.0.0/33", "::1/129",
-		"fe80::1%eth0/128",
-	} {
-		_, err := middleware.ParseTrustedProxies([]string{cidr})
-		if err == nil || !strings.Contains(err.Error(), "TRUSTED_PROXIES") {
-			t.Errorf("%q: error = %v, want one naming TRUSTED_PROXIES",
-				cidr, err)
-		}
+	_, err := middleware.ParseTrustedProxies([]string{"not-a-cidr"})
+	if err == nil {
+		t.Fatal("expected error for malformed CIDR, got nil")
 	}
 }
 
-func TestParseTrustedProxiesAcceptsCIDRs(t *testing.T) {
-	t.Parallel()
-
-	mustPrefixes(t, "172.17.0.1/32", "10.0.0.0/8", "2001:db8::1/128",
-		"2001:db8::/32", "::ffff:192.0.2.1/128")
-}
-
 type clientIPCase struct {
 	name       string
 	remoteAddr string
@@ -322,250 +300,3 @@ func TestRecovererRepanicsOnAbortHandler(t *testing.T) {
 		t.Errorf("abort was logged: %q", logbuf.String())
 	}
 }
-
-// TestLoggingCutsRequestStringsToBound sends an over-long URL and
-// over-long header values, and checks the request log writes each
-// one cut to logger.MaxLoggedFieldBytes.
-func TestLoggingCutsRequestStringsToBound(t *testing.T) {
-	t.Parallel()
-
-	long := strings.Repeat("a", 2*logger.MaxLoggedFieldBytes)
-
-	var logbuf bytes.Buffer
-
-	mw := middleware.NewWithLogger(
-		slog.New(slog.NewJSONHandler(&logbuf, nil)),
-	)
-
-	handler := chimiddleware.RequestID(mw.Logging()(okHandler()))
-
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodGet, "/"+long, http.NoBody)
-	req.Header.Set("User-Agent", long)
-	req.Header.Set("Referer", long)
-	req.Header.Set("X-Request-Id", long)
-
-	handler.ServeHTTP(httptest.NewRecorder(), req)
-
-	var logged map[string]any
-
-	err := json.Unmarshal(logbuf.Bytes(), &logged)
-	if err != nil {
-		t.Fatalf("log line not JSON: %v (%q)", err, logbuf.String())
-	}
-
-	want := map[string]string{
-		"url":        ("/" + long)[:logger.MaxLoggedFieldBytes],
-		"useragent":  long[:logger.MaxLoggedFieldBytes],
-		"referer":    long[:logger.MaxLoggedFieldBytes],
-		"request_id": long[:logger.MaxLoggedFieldBytes],
-	}
-
-	for field, value := range want {
-		if logged[field] != value {
-			t.Errorf("logged %s = %q, want it cut to %d bytes",
-				field, logged[field], logger.MaxLoggedFieldBytes)
-		}
-	}
-}
-
-// okHandler stands in for the route a middleware guards.
-func okHandler() http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		w.WriteHeader(http.StatusOK)
-	})
-}
-
-// TestRateLimitRefusesPastAllowanceThenResets checks one client
-// address: it may use its whole allowance at once, the next request
-// is refused with 429, and later it may send again.
-func TestRateLimitRefusesPastAllowanceThenResets(t *testing.T) {
-	t.Parallel()
-
-	// synctest runs this on a fake clock: time.Sleep returns at once,
-	// with the clock moved on.
-	synctest.Test(t, func(t *testing.T) {
-		const perMinute = 2
-
-		handler := (&middleware.Middleware{}).RateLimit(perMinute)(okHandler())
-
-		post := func() *httptest.ResponseRecorder {
-			rec := httptest.NewRecorder()
-			req := httptest.NewRequestWithContext(t.Context(),
-				http.MethodPost, "/api/v1/reports", http.NoBody)
-			handler.ServeHTTP(rec, req)
-
-			return rec
-		}
-
-		for i := range perMinute {
-			if code := post().Code; code != http.StatusOK {
-				t.Fatalf("request %d: status = %d, want %d",
-					i+1, code, http.StatusOK)
-			}
-		}
-
-		rec := post()
-		if rec.Code != http.StatusTooManyRequests {
-			t.Fatalf("request past the allowance: status = %d, want %d",
-				rec.Code, http.StatusTooManyRequests)
-		}
-
-		if got := rec.Body.String(); got != "{\"status\":\"error\"}\n" {
-			t.Errorf("body = %q, want %q", got, "{\"status\":\"error\"}\n")
-		}
-
-		if got := rec.Header().Get("Retry-After"); got != "60" {
-			t.Fatalf("Retry-After = %q, want %q", got, "60")
-		}
-
-		// httprate also counts the previous minute's requests, fading
-		// them out over the current one, so two minutes on the whole
-		// allowance is back.
-		time.Sleep(2 * time.Minute)
-
-		for i := range perMinute {
-			if code := post().Code; code != http.StatusOK {
-				t.Fatalf("two minutes later, request %d: status = %d, want %d",
-					i+1, code, http.StatusOK)
-			}
-		}
-	})
-}
-
-// postForwarded sends handler a report from peer that names client in
-// X-Forwarded-For, and returns the status.
-func postForwarded(
-	t *testing.T,
-	handler http.Handler,
-	peer, client string,
-) int {
-	t.Helper()
-
-	rec := httptest.NewRecorder()
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodPost, "/api/v1/reports", http.NoBody)
-	req.RemoteAddr = peer
-	req.Header.Set("X-Forwarded-For", client)
-	handler.ServeHTTP(rec, req)
-
-	return rec.Code
-}
-
-// TestRateLimitIsPerForwardedClient checks that clients behind a
-// trusted proxy each get their own allowance: the limit is keyed on
-// the client address clientIP resolves, not on the proxy's.
-func TestRateLimitIsPerForwardedClient(t *testing.T) {
-	t.Parallel()
-
-	const otherClient = "203.0.113.8"
-
-	mw := middleware.NewWithTrustedProxies(mustPrefixes(t, "127.0.0.1/32"))
-	handler := mw.RateLimit(1)(okHandler())
-
-	code := postForwarded(t, handler, loopbackPeer, forwardedIP)
-	if code != http.StatusOK {
-		t.Fatalf("first request: status = %d, want %d", code, http.StatusOK)
-	}
-
-	code = postForwarded(t, handler, loopbackPeer, forwardedIP)
-	if code != http.StatusTooManyRequests {
-		t.Fatalf("same client again: status = %d, want %d",
-			code, http.StatusTooManyRequests)
-	}
-
-	code = postForwarded(t, handler, loopbackPeer, otherClient)
-	if code != http.StatusOK {
-		t.Fatalf("other client behind the same proxy: status = %d, want %d",
-			code, http.StatusOK)
-	}
-}
-
-// TestRateLimitIgnoresForwardedForFromUntrustedPeer checks that a
-// peer that is not a trusted proxy cannot get a fresh allowance by
-// naming a different client in X-Forwarded-For on each request.
-func TestRateLimitIgnoresForwardedForFromUntrustedPeer(t *testing.T) {
-	t.Parallel()
-
-	const untrustedPeer = "198.51.100.4:5000"
-
-	mw := middleware.NewWithTrustedProxies(mustPrefixes(t, "127.0.0.1/32"))
-	handler := mw.RateLimit(1)(okHandler())
-
-	code := postForwarded(t, handler, untrustedPeer, "203.0.113.8")
-	if code != http.StatusOK {
-		t.Fatalf("first request: status = %d, want %d", code, http.StatusOK)
-	}
-
-	code = postForwarded(t, handler, untrustedPeer, "203.0.113.9")
-	if code != http.StatusTooManyRequests {
-		t.Fatalf("same peer naming another client: status = %d, want %d",
-			code, http.StatusTooManyRequests)
-	}
-}
-
-// preflight sends cors the preflight request a browser makes before
-// it POSTs JSON from origin.
-func preflight(
-	t *testing.T,
-	cors func(http.Handler) http.Handler,
-	origin string,
-) *httptest.ResponseRecorder {
-	t.Helper()
-
-	rec := httptest.NewRecorder()
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodOptions, "/api/v1/reports", http.NoBody)
-	req.Header.Set("Origin", origin)
-	req.Header.Set("Access-Control-Request-Method", http.MethodPost)
-	req.Header.Set("Access-Control-Request-Headers", "content-type")
-	cors(okHandler()).ServeHTTP(rec, req)
-
-	return rec
-}
-
-// TestCORSWithoutOriginsAddsNoHeaders checks the default: with no
-// origins configured, no origin is given any CORS header.
-func TestCORSWithoutOriginsAddsNoHeaders(t *testing.T) {
-	t.Parallel()
-
-	rec := preflight(t,
-		(&middleware.Middleware{}).CORS(nil), "https://elsewhere.example")
-
-	for name := range rec.Header() {
-		if strings.HasPrefix(name, "Access-Control-") {
-			t.Errorf("CORS header %s set with no origins configured", name)
-		}
-	}
-}
-
-func TestCORSAllowsOnlyListedOrigins(t *testing.T) {
-	t.Parallel()
-
-	const listed = "https://netwatch.example"
-
-	cors := (&middleware.Middleware{}).CORS([]string{listed})
-
-	cases := []struct {
-		name   string
-		origin string
-		want   string
-	}{
-		{name: "listed origin allowed", origin: listed, want: listed},
-		{name: "other origin refused", origin: "https://elsewhere.example"},
-	}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			rec := preflight(t, cors, tc.origin)
-
-			got := rec.Header().Get("Access-Control-Allow-Origin")
-			if got != tc.want {
-				t.Errorf("Access-Control-Allow-Origin = %q, want %q",
-					got, tc.want)
-			}
-		})
-	}
-}

backend/internal/reportbuf/export_test.go

@@ -1,15 +0,0 @@
-package reportbuf
-
-import "time"
-
-// Flush writes the buffered reports to a file now, as the periodic
-// flush does, so tests need not wait a minute for it.
-func (b *Buffer) Flush() error {
-	return b.flushLocked()
-}
-
-// StopClock makes every report file the buffer writes from now on
-// carry the timestamp at, as if all were written in one millisecond.
-func (b *Buffer) StopClock(at time.Time) {
-	b.now = func() time.Time { return at }
-}

backend/internal/reportbuf/reportbuf.go

@@ -6,15 +6,12 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/fs"
 	"log/slog"
 	"os"
 	"path/filepath"
-	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"sneak.berlin/go/netwatch/internal/config"
@@ -30,17 +27,8 @@ const (
 	defaultDataDir                 = "./data/reports"
 	dirPerms           fs.FileMode = 0o750
 	filePerms          fs.FileMode = 0o640
-
-	// Report files are named filePrefix + timestamp + "-" + number +
-	// fileSuffix; see writeFile.
-	filePrefix = "reports-"
-	fileSuffix = ".jsonl.zst"
 )
 
-// ErrFull is returned by Append when storing the report would
-// take the report files past the configured maximum size.
-var ErrFull = errors.New("report files at their size cap")
-
 // Params defines the dependencies for Buffer.
 type Params struct {
 	fx.In
@@ -56,19 +44,8 @@ type Buffer struct {
 	dataDir  string
 	done     chan struct{}
 	log      *slog.Logger
-	maxBytes int64
 	mu       sync.Mutex
-	// now is the clock report files are named by: time.Now, except
-	// in tests that need two flushes to share a timestamp.
-	now func() time.Time
-	// seq numbers the report files, so that two named in the same
-	// millisecond still get different names.
-	seq      atomic.Uint64
 	stopOnce sync.Once
-	// usedBytes is what Append checks against maxBytes: the size
-	// of the report files in dataDir, plus the reports not yet
-	// written to one at their uncompressed size.
-	usedBytes int64
 }
 
 // New creates a Buffer and registers lifecycle hooks to
@@ -83,11 +60,9 @@ func New(
 	}
 
 	b := &Buffer{
-		dataDir:  dir,
-		done:     make(chan struct{}),
-		log:      params.Logger.Get(),
-		maxBytes: params.Config.DataDirMaxBytes,
-		now:      time.Now,
+		dataDir: dir,
+		done:    make(chan struct{}),
+		log:     params.Logger.Get(),
 	}
 
 	lc.Append(fx.Hook{
@@ -97,12 +72,6 @@ func New(
 				return fmt.Errorf("create data dir: %w", err)
 			}
 
-			// Report files left by earlier runs count too.
-			b.usedBytes, err = reportFilesSize(b.dataDir)
-			if err != nil {
-				return err
-			}
-
 			go b.flushLoop()
 
 			return nil
@@ -128,27 +97,15 @@ func New(
 }
 
 // Append marshals v as a single JSON line and appends it to
-// the buffer. It stores nothing and returns ErrFull if the line
-// would take usedBytes past maxBytes. If the buffer reaches the
-// size threshold, it is drained and written to disk
-// asynchronously.
+// the buffer. If the buffer reaches the size threshold, it is
+// drained and written to disk asynchronously.
 func (b *Buffer) Append(v any) error {
 	line, err := json.Marshal(v)
 	if err != nil {
 		return fmt.Errorf("marshal report: %w", err)
 	}
 
-	lineBytes := int64(len(line)) + 1 // with its newline
-
 	b.mu.Lock()
-
-	if b.usedBytes+lineBytes > b.maxBytes {
-		b.mu.Unlock()
-
-		return ErrFull
-	}
-
-	b.usedBytes += lineBytes
 	b.buf.Write(line)
 	b.buf.WriteByte('\n')
 
@@ -220,14 +177,12 @@ func (b *Buffer) drainBuf() []byte {
 // writeFile creates a timestamped zstd-compressed JSONL file
 // in the data directory.
 func (b *Buffer) writeFile(data []byte) error {
-	// 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")
-	name := fmt.Sprintf("%s%s-%d%s", filePrefix, ts, b.seq.Add(1), fileSuffix)
+	ts := time.Now().UTC().Format("2006-01-02T15-04-05.000Z")
+	name := fmt.Sprintf("reports-%s.jsonl.zst", ts)
 	path := filepath.Join(b.dataDir, name)
 
 	// path is built from the operator-supplied dataDir plus a
-	// generated timestamp and number, so it carries no external input.
+	// generated timestamp, so it carries no external input.
 	f, err := os.OpenFile( //nolint:gosec // see comment above
 		path,
 		os.O_WRONLY|os.O_CREATE|os.O_EXCL,
@@ -259,51 +214,10 @@ func (b *Buffer) writeFile(data []byte) error {
 		return fmt.Errorf("close zstd encoder: %w", err)
 	}
 
-	info, err := f.Stat()
-	if err != nil {
-		return fmt.Errorf("stat report file: %w", err)
-	}
-
 	err = f.Close()
 	if err != nil {
 		return fmt.Errorf("close report file: %w", err)
 	}
 
-	// The reports counted at their uncompressed size while they
-	// waited; now they count as the file. After a failed write they
-	// stay counted as they were, which errs toward refusing reports
-	// early rather than letting the files pass the cap.
-	b.mu.Lock()
-	b.usedBytes += info.Size() - int64(len(data))
-	b.mu.Unlock()
-
 	return nil
 }
-
-// reportFilesSize returns the total size of the report files in
-// dir.
-func reportFilesSize(dir string) (int64, error) {
-	entries, err := os.ReadDir(dir)
-	if err != nil {
-		return 0, fmt.Errorf("read data dir: %w", err)
-	}
-
-	var total int64
-
-	for _, entry := range entries {
-		name := entry.Name()
-		if !strings.HasPrefix(name, filePrefix) ||
-			!strings.HasSuffix(name, fileSuffix) {
-			continue
-		}
-
-		info, err := entry.Info()
-		if err != nil {
-			return 0, fmt.Errorf("stat report file: %w", err)
-		}
-
-		total += info.Size()
-	}
-
-	return total, nil
-}

backend/internal/reportbuf/reportbuf_test.go

@@ -1,26 +1,17 @@
 package reportbuf_test
 
 import (
-	"encoding/json"
 	"errors"
-	"fmt"
 	"io/fs"
 	"os"
-	"path/filepath"
-	"slices"
-	"strconv"
 	"strings"
-	"sync"
-	"sync/atomic"
 	"testing"
-	"time"
 
 	"sneak.berlin/go/netwatch/internal/config"
 	"sneak.berlin/go/netwatch/internal/globals"
 	"sneak.berlin/go/netwatch/internal/logger"
 	"sneak.berlin/go/netwatch/internal/reportbuf"
 
-	"github.com/klauspost/compress/zstd"
 	"go.uber.org/fx"
 	"go.uber.org/fx/fxtest"
 )
@@ -103,319 +94,6 @@ func TestFailedFinalFlushFailsStop(t *testing.T) {
 	}
 }
 
-// startBuffer starts a Buffer through fx, as main does, with the
-// DATA_DIR and DATA_DIR_MAX_BYTES the calling test has set.
-func startBuffer(t *testing.T) *reportbuf.Buffer {
-	t.Helper()
-
-	var buf *reportbuf.Buffer
-
-	app := fxtest.New(t,
-		fx.Provide(
-			globals.New,
-			logger.New,
-			config.New,
-			reportbuf.New,
-		),
-		fx.Populate(&buf),
-	)
-
-	app.RequireStart()
-	t.Cleanup(app.RequireStop)
-
-	return buf
-}
-
-// lineBytes is what one report takes in the buffer: its JSON and a
-// newline.
-func lineBytes(t *testing.T, report any) int {
-	t.Helper()
-
-	line, err := json.Marshal(report)
-	if err != nil {
-		t.Fatalf("marshal report: %v", err)
-	}
-
-	return len(line) + 1
-}
-
-func TestAppendPastCapIsRefused(t *testing.T) {
-	report := map[string]string{"id": "cap"}
-
-	t.Setenv("DATA_DIR", t.TempDir())
-	t.Setenv("DATA_DIR_MAX_BYTES", strconv.Itoa(lineBytes(t, report)))
-
-	buf := startBuffer(t)
-
-	err := buf.Append(report)
-	if err != nil {
-		t.Fatalf("report that fills the cap exactly: %v", err)
-	}
-
-	err = buf.Append(report)
-	if !errors.Is(err, reportbuf.ErrFull) {
-		t.Fatalf("report past the cap: error = %v, want ErrFull", err)
-	}
-}
-
-// TestCapCountsReportFilesAlreadyInDataDir starts on a data
-// directory holding a report file from an earlier run, and a file
-// that is not a report, which must not count.
-func TestCapCountsReportFilesAlreadyInDataDir(t *testing.T) {
-	const earlierBytes = 100
-
-	report := map[string]string{"id": "cap"}
-	dir := t.TempDir()
-
-	writeBytes(t, filepath.Join(dir, "reports-2026-01-01T00-00-00.000Z.jsonl.zst"),
-		earlierBytes)
-	writeBytes(t, filepath.Join(dir, "notes.txt"), 10*earlierBytes)
-
-	t.Setenv("DATA_DIR", dir)
-	t.Setenv("DATA_DIR_MAX_BYTES",
-		strconv.Itoa(earlierBytes+lineBytes(t, report)))
-
-	buf := startBuffer(t)
-
-	err := buf.Append(report)
-	if err != nil {
-		t.Fatalf("report that fills the cap exactly: %v", err)
-	}
-
-	err = buf.Append(report)
-	if !errors.Is(err, reportbuf.ErrFull) {
-		t.Fatalf("report past the cap: error = %v, want ErrFull", err)
-	}
-}
-
-// TestWrittenReportsCountAtFileSize checks that once reports are
-// written, they count as their compressed file, not their
-// uncompressed size, which frees room under the cap.
-func TestWrittenReportsCountAtFileSize(t *testing.T) {
-	// Repetitive, so its file is far smaller than its JSON.
-	report := map[string]string{"id": strings.Repeat("a", 1000)}
-	size := lineBytes(t, report)
-
-	t.Setenv("DATA_DIR", t.TempDir())
-	// Room for the report twice over only if the first one counts
-	// at its file's size by the time the second arrives.
-	t.Setenv("DATA_DIR_MAX_BYTES", strconv.Itoa(2*size-1))
-
-	buf := startBuffer(t)
-
-	err := buf.Append(report)
-	if err != nil {
-		t.Fatalf("first report: %v", err)
-	}
-
-	err = buf.Flush()
-	if err != nil {
-		t.Fatalf("flush: %v", err)
-	}
-
-	err = buf.Append(report)
-	if err != nil {
-		t.Fatalf("second report, after the first was written: %v", err)
-	}
-}
-
-// TestWrittenReportsKeepCounting writes one report file after another
-// under a small cap: each report must be taken while the files on disk
-// leave room for it, and refused once they do not.
-func TestWrittenReportsKeepCounting(t *testing.T) {
-	const maxBytes = 200
-
-	report := map[string]string{"id": "written"}
-	size := int64(lineBytes(t, report))
-	dir := t.TempDir()
-
-	t.Setenv("DATA_DIR", dir)
-	t.Setenv("DATA_DIR_MAX_BYTES", strconv.Itoa(maxBytes))
-
-	buf := startBuffer(t)
-
-	// Every file takes at least a byte, so they fill the cap within
-	// maxBytes rounds.
-	for range maxBytes {
-		used := reportFilesBytes(t, dir)
-
-		err := buf.Append(report)
-		if used+size > maxBytes {
-			if !errors.Is(err, reportbuf.ErrFull) {
-				t.Fatalf("with %d bytes of report files: error = %v, "+
-					"want ErrFull", used, err)
-			}
-
-			return
-		}
-
-		if err != nil {
-			t.Fatalf("with %d bytes of report files: %v", used, err)
-		}
-
-		err = buf.Flush()
-		if err != nil {
-			t.Fatalf("flush: %v", err)
-		}
-	}
-
-	t.Fatal("the report files never filled the cap")
-}
-
-// 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
-// under one lock.
-func TestConcurrentAppendsStopAtCap(t *testing.T) {
-	const (
-		roomFor = 5
-		senders = 50
-	)
-
-	// Large, so each Append takes long enough for the senders to
-	// overlap while the cap is reached.
-	report := map[string]string{"id": strings.Repeat("a", 1_000_000)}
-
-	t.Setenv("DATA_DIR", t.TempDir())
-	t.Setenv("DATA_DIR_MAX_BYTES",
-		strconv.Itoa(roomFor*lineBytes(t, report)))
-
-	buf := startBuffer(t)
-
-	var (
-		taken atomic.Int64
-		wg    sync.WaitGroup
-	)
-
-	start := make(chan struct{})
-
-	for range senders {
-		wg.Go(func() {
-			<-start
-
-			err := buf.Append(report)
-			if err == nil {
-				taken.Add(1)
-			} else if !errors.Is(err, reportbuf.ErrFull) {
-				t.Errorf("append: %v", err)
-			}
-		})
-	}
-
-	close(start)
-	wg.Wait()
-
-	if got := taken.Load(); got != roomFor {
-		t.Fatalf("%d reports taken, want %d", got, roomFor)
-	}
-}
-
-// TestTwoFlushesInOneMillisecond flushes twice within one millisecond,
-// as a flush for size and the final flush at shutdown can: each flush
-// must write a file of its own, and the files must hold every report.
-func TestTwoFlushesInOneMillisecond(t *testing.T) {
-	const flushes = 2
-
-	dir := t.TempDir()
-	t.Setenv("DATA_DIR", dir)
-
-	buf := startBuffer(t)
-	buf.StopClock(time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC))
-
-	for id := 1; id <= flushes; id++ {
-		err := buf.Append(map[string]int{"id": id})
-		if err != nil {
-			t.Fatalf("append report %d: %v", id, err)
-		}
-
-		err = buf.Flush()
-		if err != nil {
-			t.Fatalf("flush %d: %v", id, err)
-		}
-	}
-
-	files := readReportFiles(t, dir)
-	if len(files) != flushes {
-		t.Fatalf("%d report files after %d flushes", len(files), flushes)
-	}
-
-	for id := 1; id <= flushes; id++ {
-		want := fmt.Sprintf(`{"id":%d}`+"\n", id)
-		if !slices.Contains(files, want) {
-			t.Fatalf("no report file holds report %d alone", id)
-		}
-	}
-}
-
-// reportFilesBytes returns the total size of the report files in dir.
-func reportFilesBytes(t *testing.T, dir string) int64 {
-	t.Helper()
-
-	paths, err := filepath.Glob(filepath.Join(dir, "reports-*.jsonl.zst"))
-	if err != nil {
-		t.Fatalf("list report files: %v", err)
-	}
-
-	var total int64
-
-	for _, path := range paths {
-		info, statErr := os.Stat(path)
-		if statErr != nil {
-			t.Fatalf("stat %s: %v", path, statErr)
-		}
-
-		total += info.Size()
-	}
-
-	return total
-}
-
-// readReportFiles returns the decompressed contents of each report
-// file in dir.
-func readReportFiles(t *testing.T, dir string) []string {
-	t.Helper()
-
-	files := os.DirFS(dir)
-
-	names, err := fs.Glob(files, "reports-*.jsonl.zst")
-	if err != nil {
-		t.Fatalf("list report files: %v", err)
-	}
-
-	dec, err := zstd.NewReader(nil)
-	if err != nil {
-		t.Fatalf("create zstd decoder: %v", err)
-	}
-	defer dec.Close()
-
-	contents := make([]string, 0, len(names))
-
-	for _, name := range names {
-		compressed, readErr := fs.ReadFile(files, name)
-		if readErr != nil {
-			t.Fatalf("read %s: %v", name, readErr)
-		}
-
-		data, decErr := dec.DecodeAll(compressed, nil)
-		if decErr != nil {
-			t.Fatalf("decompress %s: %v", name, decErr)
-		}
-
-		contents = append(contents, string(data))
-	}
-
-	return contents
-}
-
-func writeBytes(t *testing.T, path string, n int) {
-	t.Helper()
-
-	err := os.WriteFile(path, make([]byte, n), 0o600)
-	if err != nil {
-		t.Fatalf("write %s: %v", path, err)
-	}
-}
-
 func hasReportFile(t *testing.T, dir string) bool {
 	t.Helper()
 

backend/internal/server/routes.go

@@ -25,7 +25,7 @@ func (s *Server) SetupRoutes() {
 	s.router.Use(middleware.RequestID)
 	s.router.Use(s.mw.Logging())
 	s.router.Use(s.mw.SecurityHeaders())
-	s.router.Use(s.mw.CORS(s.params.Config.CORSAllowedOrigins))
+	s.router.Use(s.mw.CORS())
 	s.router.Use(s.mw.MaxBodyBytes(maxRequestBodyBytes))
 	s.router.Use(middleware.Timeout(requestTimeout))
 
@@ -35,7 +35,6 @@ func (s *Server) SetupRoutes() {
 	)
 
 	s.router.Route("/api/v1", func(r chi.Router) {
-		r.With(s.mw.RateLimit(s.params.Config.ReportsPerMinute)).
-			Post("/reports", s.h.HandleReport())
+		r.Post("/reports", s.h.HandleReport())
 	})
 }

backend/internal/server/routes_test.go

@@ -49,64 +49,6 @@ func newServer(t *testing.T) *server.Server {
 	return srv
 }
 
-// TestReportsAreRateLimited checks that POST /api/v1/reports is
-// behind the per-address rate limit, set here to two a minute.
-func TestReportsAreRateLimited(t *testing.T) {
-	t.Setenv("REPORTS_PER_MINUTE", "2")
-
-	srv := newServer(t)
-	srv.SetupRoutes()
-
-	post := func() int {
-		rec := httptest.NewRecorder()
-		req := httptest.NewRequestWithContext(t.Context(),
-			http.MethodPost, "/api/v1/reports",
-			strings.NewReader(`{"clientId":"c1","hosts":[]}`),
-		)
-		srv.ServeHTTP(rec, req)
-
-		return rec.Code
-	}
-
-	for i := range 2 {
-		if code := post(); code != http.StatusOK {
-			t.Fatalf("report %d: status = %d, want %d",
-				i+1, code, http.StatusOK)
-		}
-	}
-
-	if code := post(); code != http.StatusTooManyRequests {
-		t.Fatalf("third report in a minute: status = %d, want %d",
-			code, http.StatusTooManyRequests)
-	}
-}
-
-// TestCORSAllowedOriginsReachTheRouter checks that an origin listed in
-// CORS_ALLOWED_ORIGINS is allowed by the router, not only when handed
-// to the CORS middleware directly.
-func TestCORSAllowedOriginsReachTheRouter(t *testing.T) {
-	const origin = "https://netwatch.example:8443"
-
-	t.Setenv("CORS_ALLOWED_ORIGINS", origin)
-
-	srv := newServer(t)
-	srv.SetupRoutes()
-
-	// The preflight a browser sends before it POSTs JSON from origin.
-	rec := httptest.NewRecorder()
-	req := httptest.NewRequestWithContext(t.Context(),
-		http.MethodOptions, "/api/v1/reports", http.NoBody)
-	req.Header.Set("Origin", origin)
-	req.Header.Set("Access-Control-Request-Method", http.MethodPost)
-	req.Header.Set("Access-Control-Request-Headers", "content-type")
-	srv.ServeHTTP(rec, req)
-
-	got := rec.Header().Get("Access-Control-Allow-Origin")
-	if got != origin {
-		t.Fatalf("Access-Control-Allow-Origin = %q, want %q", got, origin)
-	}
-}
-
 // 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/script/lint

@@ -14,7 +14,7 @@ set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
-GOLANGCI_CONFIG_SHA256="a79b63a254602a5318db5d0e9a06bc71b84bf0c1d896305229d8bfed1d1b1776"
+GOLANGCI_CONFIG_SHA256="021cc83f4e6fc7c31b95b34b846723dfcf20b66b7baeea1dc40406e643346bcb"
 
 main() {
     cd "$ROOT"

bin/entrypoint.sh

@@ -8,124 +8,23 @@
 # No set -e: kill and wait return non-zero here in normal operation.
 set -u
 
-# PORT is the public port nginx listens on, 8080 when unset or empty.
-# nginx would take a value such as localhost or unix:/tmp/x.sock as an
-# 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.
-export PORT="${PORT:-8080}"
-case "$PORT" in
-    *[!0-9]*)
-        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
-    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
-# address from X-Forwarded-For only on a request from one of them, so
-# unset or empty, it trusts no one. nginx.conf includes the file written
-# here, one set_real_ip_from line per entry.
-#
-# nginx looks up an entry it cannot read as an address as a hostname,
-# and trusts what it finds (1.2.3 is found as 1.2.0.3). So each entry
-# is made a CIDR, a lone address getting /128 if it is IPv6 and /32 if
-# not, and netwatch-server checks it with the parsing it gives its own
-# 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.
-TRUSTED_PROXIES="${TRUSTED_PROXIES:-}"
-set -f
-for proxy in $(printf '%s' "$TRUSTED_PROXIES" | tr ',' ' '); do
-    case "$proxy" in
-        */*) cidr="$proxy" ;;
-        *:*) cidr="$proxy/128" ;;
-        *) cidr="$proxy/32" ;;
-    esac
-    if ! netwatch-server check-cidr "$cidr" 2> /dev/null; then
-        echo "entrypoint: TRUSTED_PROXIES must be IP addresses or CIDRs" \
-            "separated by commas; '$proxy' is neither" >&2
-        exit 1
-    fi
-    echo "set_real_ip_from $cidr;"
-done > /etc/nginx/trusted-proxies.conf
-
-# netwatch-server keeps its report files in DATA_DIR, on the /data
-# volume, which may be a host directory owned by root or by another
-# uid. /data and everything in it are given to the netwatch user here,
-# and /data and DATA_DIR get the mode the server gives a directory it
-# creates, so the host directory needs no preparing.
-#
-# This runs as root, so nothing is created or changed until DATA_DIR is
-# known to be /data or a path below it, with no '.', '..' or empty
-# part, and no part of it that exists, /data included, is a symbolic
-# link: the netwatch user can put one in /data, and root would follow
-# it anywhere in the container. Nothing else runs in the container yet,
-# so no link can appear after the check.
-export DATA_DIR="${DATA_DIR:-/data/reports}"
-data_dir_ok() {
-    # With a / added at the end, a last part of '.' or '..', and a / at
-    # the end, match these patterns too.
-    case "$DATA_DIR/" in
-        */./* | */../* | *//*) return 1 ;;
-        /data/*) ;;
-        *) return 1 ;;
-    esac
-    # Each part from DATA_DIR up to /data. [ -L ] is false for a part
-    # that does not exist.
-    dir="$DATA_DIR"
-    while [ "$dir" != /data ]; do
-        [ -L "$dir" ] && return 1
-        dir="${dir%/*}"
-    done
-    [ ! -L /data ]
-}
-if ! data_dir_ok; then
-    echo "entrypoint: DATA_DIR must be /data or a path below it, with no" \
-        "'.', '..', extra '/' or symbolic link on it, not '$DATA_DIR'" >&2
-    exit 1
-fi
-mkdir -p "$DATA_DIR" || exit 1
-# -h: a symbolic link in /data is itself given to netwatch, not what it
-# points to.
-chown -R -h netwatch:netwatch /data || exit 1
-chmod 750 /data "$DATA_DIR" || exit 1
-
 # A stop signal is only noted here; the loop below acts on it.
 stop_requested=""
 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; nginx.conf proxies to this
-# address. Its only client is nginx, so it takes the client address
-# nginx passes on from 127.0.0.1 alone, whatever TRUSTED_PROXIES 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.
-BIND_ADDRESS=127.0.0.1 PORT=8081 TRUSTED_PROXIES=127.0.0.1/32 \
+# address. 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 $! is the server's own PID.
+BIND_ADDRESS=127.0.0.1 PORT=8081 \
     su -s /bin/sh netwatch -c 'exec netwatch-server' &
 backend=$!
 
 # nginx starts through the nginx image's own entrypoint, which applies
 # the image's start-up configuration and then replaces itself with
-# nginx. Part of that start-up configuration renders nginx.conf into
-# conf.d with nginx listening on PORT. NGINX_ENVSUBST_FILTER limits
-# that rendering to PORT: a variable nginx itself uses, such as $uri,
-# would otherwise be replaced by an environment variable of the same
-# name.
-NGINX_ENVSUBST_FILTER='^PORT$' \
-    /docker-entrypoint.sh nginx -g 'daemon off;' &
+# nginx.
+/docker-entrypoint.sh nginx -g 'daemon off;' &
 nginx=$!
 
 running() {

nginx.conf

@@ -1,27 +1,14 @@
-# A template: the nginx image renders it into conf.d at container start,
-# filling in PORT and nothing else. bin/entrypoint.sh sets PORT and that
-# limit.
 server {
-    listen ${PORT};
+    listen 8080;
     server_name _;
 
-    # Keep the nginx version out of the Server header and error pages.
-    server_tokens off;
-
-    # The security headers, on every response. An add_header in a
-    # location drops every add_header from here, so a location with one
-    # of its own includes this file again.
-    include /etc/nginx/security-headers.conf;
-
     root /usr/share/nginx/html;
     index index.html;
 
-    # The client address comes from X-Forwarded-For only on a request
-    # from the reverse proxies in TRUSTED_PROXIES: bin/entrypoint.sh
-    # writes one set_real_ip_from line for each into this file, and
-    # leaves it empty when TRUSTED_PROXIES is unset, so that by default
-    # the client address is the one each request comes from.
-    include /etc/nginx/trusted-proxies.conf;
+    # Trust RFC1918 reverse proxies for X-Forwarded-For
+    set_real_ip_from 10.0.0.0/8;
+    set_real_ip_from 172.16.0.0/12;
+    set_real_ip_from 192.168.0.0/16;
     real_ip_header X-Forwarded-For;
     real_ip_recursive on;
 
@@ -37,7 +24,6 @@ server {
     location /assets/ {
         expires 1y;
         add_header Cache-Control "public, immutable";
-        include /etc/nginx/security-headers.conf;
     }
 
     # netwatch-server, the Go backend, runs in the same container and
@@ -51,16 +37,6 @@ server {
     proxy_set_header X-Forwarded-For $remote_addr;
     proxy_set_header X-Forwarded-Proto $scheme;
 
-    # netwatch-server sets the same security headers on its own
-    # responses. Its copies are dropped so that each header goes out
-    # once, as security-headers.conf sets it.
-    proxy_hide_header Strict-Transport-Security;
-    proxy_hide_header Content-Security-Policy;
-    proxy_hide_header X-Frame-Options;
-    proxy_hide_header X-Content-Type-Options;
-    proxy_hide_header Referrer-Policy;
-    proxy_hide_header Permissions-Policy;
-
     location /api/ {
         proxy_pass http://127.0.0.1:8081;
     }

script/bootstrap

@@ -3,12 +3,12 @@
 # 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 if it is at least NODE_MIN_VERSION; otherwise it is
-# installed at a pinned version via nvm (installing nvm itself first,
-# from a hash-verified release archive, never curl | sh). Go, with its
-# gofmt, is used directly if it is at least the version backend/go.mod
-# asks for; otherwise the pinned Go release is installed from its
-# hash-verified archive.
+# used directly if installed; otherwise it is installed at a pinned
+# version via nvm (installing nvm itself first, from a hash-verified
+# release archive, never curl | sh). Go, with its gofmt, is used
+# directly if it is at least the version backend/go.mod asks for;
+# otherwise the pinned Go release is installed from its hash-verified
+# archive.
 #
 # What this script installs outside the system package manager lives
 # under $HOME and is linked into ~/.local/bin, where make and the git
@@ -23,10 +23,6 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 # Pinned versions, 2026-07-07
 NODE_VERSION="22.17.0"
-# The oldest node the frontend's dependencies accept: the "engines"
-# field of puppeteer-core 25.5.0, the most demanding of them, asks for
-# 22.12.0 or newer, 2026-09-29. An older installed node is not used.
-NODE_MIN_VERSION="22.12.0"
 NVM_VERSION="0.40.3"
 # sha256 of https://github.com/nvm-sh/nvm/archive/refs/tags/v0.40.3.tar.gz
 NVM_SHA256="5f4d6aaa04a177dc93c985e31dbc411ab6b8c6e1e21d8015dbc1372625fcd1d0"
@@ -140,22 +136,8 @@ ensure_nvm() {
     rm -rf "$tmp"
 }
 
-# node_ok: the node on PATH is at least NODE_MIN_VERSION. node itself
-# compares the two: major, then minor, then patch.
-node_ok() {
-    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);
-        for (let i = 0; i < 3; i++) {
-            if (have[i] !== want[i]) process.exit(have[i] > want[i] ? 0 : 1);
-        }
-    ' "$NODE_MIN_VERSION"
-}
-
-# ensure_node: unless node_ok, install NODE_VERSION and link its node.
 ensure_node() {
-    if node_ok; then return 0; fi
+    if ! missing node; then return 0; fi
     ensure_nvm
     nvm_sh "nvm install $NODE_VERSION"
     link_bin "$HOME/.nvm/versions/node/v$NODE_VERSION/bin/node" node

script/cibuild

@@ -1,29 +1,15 @@
 #!/bin/sh
-# 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.
-# --no-cache for the same reason as script/docker: the gate phases the
-# final stage depends on are RUN steps, and a cached one is a check that
-# did not run.
+# script/cibuild: run the CI build: build the one image from Dockerfile,
+# whose stages run the checks as build steps (the backend's fmt-check,
+# lint and tests, and the frontend's test, lint and fmt-check). This is
+# the only build step the Gitea workflow runs.
 set -eu
 
-SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
-ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$SCRIPT_DIR/bootstrap"
-    "$SCRIPT_DIR/check"
-    # Own line: a failing command substitution inside an argument does
-    # not trip `set -e`, so the inline form degrades silently to an
-    # empty constant. VERSION is computed here because .dockerignore
-    # excludes .git, so `git describe` in a build stage yields an empty
-    # version without failing.
-    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
-    [ -n "$version" ] || version="unknown"
-    docker build --no-cache \
-        --build-arg VERSION="$version" \
-        -t "$("$SCRIPT_DIR/projectname")" .
+    timeout 300 docker build .
 }
 
 main "$@"

script/frontend-viewport-test

@@ -61,18 +61,10 @@ main() {
     # host.
     docker network create --internal "$NETWORK" > /dev/null
 
-    # nginx.conf is a template: the image renders it over its own
-    # default.conf, with the same port and limit bin/entrypoint.sh uses.
-    # The empty file it includes trusts no proxy, as bin/entrypoint.sh
-    # writes it when TRUSTED_PROXIES is unset. nginx.conf also includes
-    # the security headers, so the page runs under the shipped policy.
     docker run -d --rm --name "$SERVER" \
         --network "$NETWORK" --network-alias netwatch \
-        -e PORT=8080 -e NGINX_ENVSUBST_FILTER='^PORT$' \
         -v "$ROOT/dist:/usr/share/nginx/html:ro" \
-        -v "$ROOT/nginx.conf:/etc/nginx/templates/default.conf.template:ro" \
-        -v /dev/null:/etc/nginx/trusted-proxies.conf:ro \
-        -v "$ROOT/security-headers.conf:/etc/nginx/security-headers.conf:ro" \
+        -v "$ROOT/nginx.conf:/etc/nginx/conf.d/default.conf:ro" \
         "$SERVER_IMAGE" > /dev/null
 
     # The image's own entrypoint already exposes CDP on 9222 and passes

security-headers.conf

@@ -1,24 +0,0 @@
-# The security headers REPO_POLICIES.md requires on every response.
-# nginx.conf includes this file, which Dockerfile copies to
-# /etc/nginx/security-headers.conf. always sends each header on error
-# responses too.
-
-add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
-
-# Scripts and styles load only from the page's own origin. Inline ones
-# are blocked, style attributes in markup included, so style elements
-# through classes or element.style. data: images are for the favicon
-# in index.html. connect-src is * because the browser checks each probe in
-# src/main.js against it, and also every redirect the probe follows,
-# and several of those hosts redirect to others; a list of hosts here
-# would block those probes. It also covers the reports the page sends
-# to its own origin.
-add_header Content-Security-Policy "default-src 'self'; connect-src *; img-src 'self' data:; object-src 'none'; base-uri 'none'; form-action 'none'; frame-ancestors 'none'" always;
-
-add_header X-Frame-Options DENY always;
-add_header X-Content-Type-Options nosniff always;
-
-# The probed hosts are not told where the page is served from.
-add_header Referrer-Policy no-referrer always;
-
-add_header Permissions-Policy "accelerometer=(), camera=(), display-capture=(), geolocation=(), gyroscope=(), magnetometer=(), microphone=(), midi=(), payment=(), usb=()" always;

src/main.js

@@ -716,7 +716,7 @@ function hostRowHTML(host, index, showPin = true) {
         ${pinBtn}
         <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>
+            <div class="w-3 h-3 rounded-full flex-shrink-0" style="background-color: ${latencyHex(null)}"></div>
             <span class="font-medium text-white truncate">${host.name}</span>
           </div>
           <div class="latency-value text-4xl font-bold tabular-nums text-right mt-3" data-host="${index}">