Comments and documentation only; the docker build invocation and its flags
are untouched, and .dockerignore's effective rules are unchanged.
Two prose gaps from review. First, "both flags below must stay" had lost
its anchor: it ended a paragraph naming only --no-cache-filter, --target
was not introduced until the next one, and three flags follow on the
command, so a reader could pick the wrong pair. It now names --target and
--no-cache-filter explicitly.
Second, the list of things the tooling does not check covered the $stage
seam but not .dockerignore, which sits in the same trust boundary and is
the more likely thing to be edited — the first review on this change
actively suggested extending it for build artifacts. Only what reaches the
container is linted, so excluding a Go source there removes it from the
lint with no warning. Verified rather than asserted: a planted violation
plus that one path in .dockerignore yields `0 issues.` at exit 0 with the
violation still in the working tree, while excluding a file other code
still references fails loudly on `undefined:` typecheck errors instead.
The warning is recorded in script/lint alongside the $stage seam and in
.dockerignore itself, where the edit would actually be made.
golangci-lint is no longer invoked on the host anywhere in the repo.
Dockerfile.lint pins golangci/golangci-lint:v2.12.2 by digest and runs
the linter as a build step, so a successful build IS a clean lint, and
`make lint` becomes a thin shim over script/lint. This removes the host
linter install that produced a false green here, where a branch that was
genuinely red with a goconst finding reported "0 issues" off the shared
host cache; a container per run has its own cache and lock.
Two deliberate divergences from the sneak/homoicon reference shape:
- Two stages rather than one. A cached `deps` stage holds
`go mod download`, then `FROM deps AS lint` carries the source copy
and the lint run, and script/lint builds with
`--no-cache-filter=lint`. Caching of the lint result is explicitly
waived (a cached build lints nothing), and splitting the stages means
busting the lint layer does not re-fetch the module cache over the
network on every run.
- No `golangci-lint config verify` step. It resolves its JSON schema
over a live, unpinned HTTPS call: an unpinned network input inside
the one step whose purpose is a pinned, reproducible gate, and a
schema-host outage would surface as a red build. `golangci-lint run`
already fails on a malformed config. The reason is recorded in a
comment in Dockerfile.lint.
.dockerignore excludes .git only; the lint reads the Go sources,
go.mod/go.sum and .golangci.yml, none of which come from there.
The TODO.md scaffold-exemption note is narrowed rather than dropped:
Dockerfile.lint and script/lint are now permitted and required, while CI
config, REPO_POLICIES.md, an application Dockerfile and any other
script/ entrypoint still are not.
Verified, since a green docker build is the classic false green: two
consecutive script/lint runs on an unchanged tree each showed the
`golangci-lint run` layer executing (9.8s and 7.9s, both "0 issues.")
while the deps layers reported CACHED; a deliberate indent-error-flow
violation failed the build naming that finding and the unused one, and a
revert went clean again. `make check` green.
