Gate the build on Docker lint and test phases (closes #40, closes #30)
check / check (push) Successful in 5m12s

Per the owner ruling on issue 40, linting and testing are phases of the
main Dockerfile rather than a separate lint file. script/lint and
script/test build one phase each by name with caching disabled, and the
final stage copies a harmless file from each so the image cannot be built
unless both passed. A stage that is not the last is built only when
something depends on it or --target names it, so the gates are invoked by
name and the edges kept. script/check runs the gates and builds no image
of its own; script/cibuild bootstraps first, because CI runs it alone and
fmt-check is native. fmt and fmt-check source nvm for the pinned node
before calling yarn, which bootstrap installs but leaves off its caller's
PATH. Every build in script/ is tagged and uncached. Issue 30 closes too:
a container has its own lint cache and lock.

Model: opus-5
This commit is contained in:
2026-09-09 11:44:59 +00:00
parent 7b55c444ae
commit c4d5546e86
14 changed files with 381 additions and 136 deletions
+137 -75
View File
@@ -60,17 +60,28 @@ style conventions are in separate documents:
prerequisite since nvm requires bash. yarn is then pinned via
`corepack prepare yarn@<version> --activate`. Never install "latest" or "lts";
always exact versions. `script/cibuild` runs the CI build: it changes to the
repo root and runs `docker build --no-cache .`; the Gitea workflow calls it.
Four further scripts are our own extensions to the standard: `script/check`
runs `script/test`, `script/lint`, and `script/fmt-check`; `script/precommit`
is what the git pre-commit hook runs, and it calls `script/check`;
`script/install-precommit` installs the git pre-commit hook (the `make hooks`
target shims to it); and `script/projectname` (literally that filename) simply
outputs the project's name. Scripts that need the name call
`script/projectname` — e.g. `script/docker` assembles its image tag from it —
so those scripts stay byte-identical across all repos. Repo-type-specific
pre-commit extras (e.g. `go mod tidy` verification in Go repos) belong in
`script/precommit`, not in the hook itself. Model scripts are at
repo root, runs `script/bootstrap`, runs `script/check`, and builds the image
with the version; the Gitea workflow calls it. **`script/cibuild` runs
`script/bootstrap` first**, because the workflow checks out the repo and runs
nothing else, while `script/fmt-check` runs the formatter on the host: on a
pristine checkout with nothing installed the run dies there, after the
containerised gates have passed. **The bootstrap alone is not enough**:
`script/bootstrap` installs node and yarn under nvm and leaves neither on the
`PATH` of the shell that called it, so a bare `yarn` still exits 127. The host
entrypoints that need yarn — `script/fmt` and `script/fmt-check` — therefore
source nvm for the pinned node version before invoking it, exactly as
`script/bootstrap`'s own install step does. A runner carrying nothing but
docker and git then gets through `script/check`. Four further scripts are our
own extensions to the standard: `script/check` runs `script/test`,
`script/lint` and `script/fmt-check`; `script/precommit` is what the git
pre-commit hook runs, and it calls `script/check`; `script/install-precommit`
installs the git pre-commit hook (the `make hooks` target shims to it); and
`script/projectname` (literally that filename) simply outputs the project's
name. Scripts that need the name call `script/projectname` — e.g.
`script/docker` assembles its image tag from it — so those scripts stay
byte-identical across all repos. Repo-type-specific pre-commit extras (e.g.
`go mod tidy` verification in Go repos) belong in `script/precommit`, not in
the hook itself. Model scripts are at
`https://git.eeqj.de/sneak/prompts/raw/branch/main/script/<name>`. The README
must document the provided scripts in an **Entrypoints** section (see the
README requirements below).
@@ -89,97 +100,140 @@ style conventions are in separate documents:
contributor should be able to understand the entire development workflow by
reading the Makefile.
- Every repo should have a `Dockerfile`. All Dockerfiles must run `make check`
as a build step so the build fails if the branch is not green. For non-server
repos, the Dockerfile should bring up a development environment and run
`make check`. For server repos, `make check` should run as an early build
stage before the final image is assembled. Dockerfiles install development
prerequisites by running `script/bootstrap` rather than duplicating installs
inline; COPY `script/` and the dependency manifests (`package.json` +
`yarn.lock`, `go.mod` + `go.sum`, etc.) before running it so the bootstrap
layer stays cached until dependencies change.
- Every repo should have a `Dockerfile`, and it carries the repo's gates: a
`lint` phase and a `test` phase, with the final stage depending on both so the
image cannot be built unless they pass. For non-server repos the final stage
brings up a development environment; for server repos it is the runtime image.
Dockerfiles install development prerequisites by running `script/bootstrap`
rather than duplicating installs inline; COPY `script/` and the dependency
manifests (`package.json` + `yarn.lock`, `go.mod` + `go.sum`, etc.) before
running it.
- **Linting and testing run in Docker, as phases of the `Dockerfile`.** There is
no separate lint file. `script/lint` and `script/test` each build one phase
and nothing else:
```sh
docker build --no-cache --target lint -t "$(script/projectname)-lint" .
docker build --no-cache --target test -t "$(script/projectname)-test" .
```
**A stage that is not the last one in the file is built only when the final
stage's chain depends on it, or when `--target` names it.** That is why the
two gates are always invoked by name here, and why the final stage carries a
`COPY --from=` of a harmless file from each of them: without that edge a
plain `docker build .` builds the last stage alone and exits 0 having linted
and tested nothing.
**Every `docker build` in `script/` is tagged**, here and in
`script/cibuild` and `script/docker`. An untagged build leaves a dangling
image behind on every invocation, on every developer host and every CI
runner; a tagged one replaces the previous image.
Inside a phase the tool is invoked directly — `golangci-lint`, `go test`,
`eslint`, `prettier` — never through `make lint` or `script/test`, which are
themselves a `docker build` and would recurse into a daemon that does not
exist in a build step. Formatting is the exception and stays on the host:
`script/fmt` writes the working tree, and `script/fmt-check` is its
read-only twin.
**No lint verdict may come from a host invocation of the linter.** On a
shared host golangci-lint reads a result cache keyed on file content rather
than location, so a second checkout of the same content is served the first
one's findings, and a host-global lock in `$TMPDIR` makes concurrent runs
exit non-zero with `parallel golangci-lint is running` — a status a caller
cannot tell from real findings. Both have produced wrong verdicts in this
org, in both directions. A container has its own cache, its own `TMPDIR` and
a digest-pinned binary, so neither is reachable.
- **Any build that runs checks is built with `--no-cache`.** Docker invalidates
a `COPY` layer only when the copied content changes, so on an unchanged tree
the check `RUN` is served from cache, nothing executes, and the build still
exits 0. `script/cibuild` and `script/docker` therefore pass `--no-cache`, and
a bare `docker build .` is not evidence that anything ran: a sub-second build
reporting success is a cache hit, not a result. Never invalidate by pruning —
`docker builder prune` and friends destroy a build cache shared with every
other build on the host.
exits 0. Every `docker build` in `script/` therefore passes `--no-cache`:
`script/lint`, `script/test`, `script/cibuild` and `script/docker` are the
four, and there is no fifth — `script/check` runs the two gate phases and
`script/fmt-check`, and builds no image of its own. A bare `docker build .` is
not evidence that anything ran: a sub-second build reporting success is a
cache hit, not a result. Never invalidate by pruning — `docker builder prune`
and friends destroy a build cache shared with every other build on the host.
- **Dockerfiles must use a separate lint stage for fail-fast feedback.** Go
repos use a multistage build where linting runs in an independent stage based
on the `golangci/golangci-lint` image (pinned by hash). This stage runs
`make fmt-check` and `make lint` before the full build begins. The build stage
then declares an explicit dependency on the lint stage via
`COPY --from=lint /src/go.sum /dev/null`, which forces BuildKit to complete
linting before proceeding to compilation and tests. This ensures lint failures
surface in seconds rather than minutes, without blocking on dependency
download or compilation in the build stage.
The standard pattern for a Go repo Dockerfile is:
- **The gate phases are separate stages, and the build stage depends on both.**
The lint phase is based on the `golangci/golangci-lint` image (pinned by
hash), so lint failures surface in seconds rather than after a full compile,
and the test phase is based on the Go image. The canonical Go repo
`Dockerfile`:
```dockerfile
# Lint stage — fast feedback on formatting and lint issues
# Lint phase
# golangci/golangci-lint:v2.x.x, YYYY-MM-DD
FROM golangci/golangci-lint@sha256:... AS lint
WORKDIR /src
COPY go.mod go.sum ./
RUN go mod download
COPY . .
RUN make fmt-check
RUN make lint
RUN golangci-lint run --config .golangci.yml ./...
# Build stage
# Test phase
# golang:1.x-alpine, YYYY-MM-DD
FROM golang@sha256:... AS test
WORKDIR /src
COPY go.mod go.sum ./
RUN go mod download
COPY . .
RUN go test -timeout 90s -race -cover ./... || \
{ echo "--- Rerunning with -v for details ---"; \
go test -timeout 90s -race -v ./...; exit 1; }
# Build stage. Nothing is wanted from either phase above; the copies
# are what make BuildKit build them first, so this stage cannot run
# unless lint and test passed.
# golang:1.x-alpine, YYYY-MM-DD
FROM golang@sha256:... AS builder
COPY --from=lint /src/go.sum /dev/null
COPY --from=test /src/go.sum /dev/null
WORKDIR /src
# Force BuildKit to run the lint stage before proceeding
COPY --from=lint /src/go.sum /dev/null
COPY go.mod go.sum ./
RUN go mod download
COPY . .
RUN make test
ARG VERSION=dev
RUN CGO_ENABLED=0 go build -trimpath \
-ldflags="-s -w -X main.Version=${VERSION}" \
-o /app ./cmd/app/
# Runtime stage
# Runtime stage, and the last one
FROM alpine@sha256:...
COPY --from=builder /app /usr/local/bin/app
ENTRYPOINT ["app"]
```
Key points:
- The lint stage uses the `golangci/golangci-lint` image directly (it
includes both Go and the linter), so there is no need to install the
linter separately.
- `COPY --from=lint /src/go.sum /dev/null` is a no-op file copy that creates
a stage dependency. BuildKit runs stages in parallel by default; without
this line, the build stage would not wait for lint to finish and a lint
failure might not fail the overall build.
- The lint phase uses the `golangci/golangci-lint` image directly (it has
both Go and the linter), so nothing needs installing.
- `COPY --from=<phase> /src/go.sum /dev/null` is a no-op copy whose only
purpose is the ordering edge. BuildKit runs stages in parallel by default,
and a stage nothing depends on is not built at all, so without these two
lines a red gate would not fail the build.
- Keep the runtime stage last, and if you add a stage after it, give it the
same two copies. A plain `docker build .` builds the last stage's chain
and nothing else.
- If the project uses `//go:embed` directives that reference build artifacts
(e.g. a web frontend compiled in a separate stage), the lint stage must
(e.g. a web frontend compiled in a separate stage), the lint phase must
create placeholder files so the embed directives resolve. Example:
`RUN mkdir -p web/dist && touch web/dist/index.html web/dist/style.css`.
The lint stage should not depend on the actual build output — it exists to
fail fast.
- If the project requires CGO or system libraries for linting (e.g.
`vips-dev`), install them in the lint stage with `apk add`.
- The build stage runs `make test` after compilation setup. Tests run in the
build stage, not the lint stage, because they may require compiled
artifacts or heavier dependencies.
`vips-dev`), install them in the lint phase with `apk add`.
- `ARG VERSION=dev` is declared in the stage that compiles and supplied by
`script/docker` and `script/cibuild`; no stage may call `git describe`.
- Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
runs `script/cibuild` (which runs `docker build --no-cache .`) on push. Since
the Dockerfile already runs `make check`, a successful build implies all
checks pass — an implication that holds only because of the `--no-cache`
above.
runs `script/cibuild` on push, and checks out the repo as its only other step.
That script bootstraps, runs the gate phases, and then builds the image, so a
successful run means every check passed; a bare `docker build .` does not
carry the same guarantee, because its gate phases may come from the cache. The
image build is uncached and so runs the gate phases a second time. That is the
price of the rule above, and it is worth paying: the image that ships is built
from a run of its own gates rather than from a cache entry.
- Use platform-standard formatters: `black` for Python, `prettier` for
JS/CSS/Markdown/HTML, `go fmt` for Go. Always use default configuration with
@@ -203,15 +257,17 @@ style conventions are in separate documents:
suite that exceeds it fails. Under 20 seconds is the target. A suite between
20 and 60 seconds is still green, but the overage must be filed as an
improvement bug against that repo. Add a 90-second timeout to the test
invocation in the Makefile (`go test -timeout 90s`). The backstop deliberately
sits above the hard cap so that it catches a genuinely hung test rather than a
merely slow one.
invocation (`go test -timeout 90s`). The backstop deliberately sits above the
hard cap so that it catches a genuinely hung test rather than a merely slow
one.
- **`make test` should use the conditional verbose rerun pattern.** Run tests
without `-v` (verbose) first. If tests fail, automatically rerun with `-v` to
show full output. This keeps CI logs and `docker build` output clean on
success (just package/suite summaries) while providing full diagnostic detail
on failure (every test case, every assertion). The general shell pattern:
- **The test command should use the conditional verbose rerun pattern.** Run
tests without `-v` (verbose) first. If tests fail, automatically rerun with
`-v` to show full output. This keeps CI logs and `docker build` output clean
on success (just package/suite summaries) while providing full diagnostic
detail on failure (every test case, every assertion). The command lives in the
`test` phase of the `Dockerfile`, since `script/test` builds that phase; the
Makefile form below is the same pattern for any repo-local invocation:
```makefile
test:
@@ -321,7 +377,9 @@ style conventions are in separate documents:
# trip `set -e`, so the inline form degrades to an empty constant.
version="$(git describe --tags --always --dirty 2>/dev/null || true)"
[ -n "$version" ] || version="unknown"
docker build --no-cache --build-arg VERSION="$version" .
docker build --no-cache \
--build-arg VERSION="$version" \
-t "$(script/projectname)" .
```
`--always` makes an untagged repo yield an abbreviated commit hash rather
@@ -368,8 +426,12 @@ style conventions are in separate documents:
`test-support` depguard rule, where a repo names its own test-support packages
by full import path. A repo adds entries there and changes nothing else, and a
re-vendor carries its entries forward. The canonical golangci-lint version is
v2.12.2 (released 2026-05-06), installed commit-pinned via
`go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@c0d3ddc9cf3faa61a4e378e879ece580256d76e5`.
v2.12.2 (released 2026-05-06), pinned as the digest of the lint phase's base
image
(`golangci/golangci-lint@sha256:5cceeef04e53efe1470638d4b4b4f5ceefd574955ab3941b2d9a68a8c9ad5240`,
which reports `2.12.2 built with go1.26.2 from c0d3ddc9`). That digest is the
only pin, since no repo installs golangci-lint on the host: bumping the
version means changing it and nothing else.
- **`script/bootstrap` installs a pinned tool by comparing versions, never by
testing presence.** An `if ! command -v <tool>; then install; fi` guard tests