Install Dockerfile build dependencies through script/bootstrap (closes #95)

The Dockerfile lint and build stages and Dockerfile.lint each carried
their own apk add list, a copy of what script/bootstrap installs. They
now copy script/, go.mod and go.sum and run script/bootstrap, so that
layer is reused until one of those changes. script/bootstrap gains a C
compiler check: the golang image has none, and cgo needs one.

The build adds -trimpath and -s -w; CGO_ENABLED=1 stays, as govips
links libvips. ARG VERSION moves to just above the build, so a new
version reruns neither script/bootstrap nor the tests.

Model: opus-5-5

Dockerfile

@@ -3,13 +3,14 @@
 # golangci/golangci-lint:v2.12.2-alpine, 2026-08-07
 FROM golangci/golangci-lint:v2.12.2-alpine@sha256:91b27804074a0bacea298707f016911e60cf0cdbc6c7bf5ccacb5f0606d18d60 AS lint
 
-RUN apk add --no-cache make build-base vips-dev libheif-dev pkgconfig
-
 WORKDIR /src
 
-# Copy go mod files first for better layer caching
+# script/bootstrap installs the build dependencies and downloads the Go
+# modules. Only script/, go.mod and go.sum are copied first, so this
+# layer is reused until one of them changes.
+COPY script/ ./script/
 COPY go.mod go.sum ./
-RUN go mod download
+RUN script/bootstrap
 
 # Copy source code
 COPY . .
@@ -28,20 +29,12 @@ FROM golang:1.25.4-alpine@sha256:d3f0cf7723f3429e3f9ed846243970b20a2de7bae6a5b66
 # Depend on lint stage passing
 COPY --from=lint /src/go.sum /dev/null
 
-ARG VERSION=dev
-
-# Install build dependencies for CGO image libraries
-RUN apk add --no-cache \
-    build-base \
-    vips-dev \
-    libheif-dev \
-    pkgconfig
-
 WORKDIR /src
 
-# Copy go mod files first for better layer caching
+# Build dependencies and Go modules, as in the lint stage
+COPY script/ ./script/
 COPY go.mod go.sum ./
-RUN GOTOOLCHAIN=auto go mod download
+RUN script/bootstrap
 
 # Copy source code
 COPY . .
@@ -49,8 +42,14 @@ COPY . .
 # Run tests
 RUN make test
 
-# Build with CGO enabled
+# VERSION is declared here, not earlier: a new value reruns only the
-RUN CGO_ENABLED=1 GOTOOLCHAIN=auto go build -ldflags "-X main.Version=${VERSION}" -o /pixad ./cmd/pixad
+# build, not script/bootstrap or the tests. CGO stays enabled for
+# govips; -trimpath keeps build paths out of the binary, and -s -w
+# leave out the symbol table and debug information.
+ARG VERSION=dev
+RUN CGO_ENABLED=1 GOTOOLCHAIN=auto go build -trimpath \
+    -ldflags "-s -w -X main.Version=${VERSION}" \
+    -o /pixad ./cmd/pixad
 
 # Runtime stage
 # alpine:3.21, 2026-02-25

Dockerfile.lint

@@ -6,16 +6,16 @@
 # golangci/golangci-lint:v2.12.2-alpine, 2026-08-07
 FROM golangci/golangci-lint:v2.12.2-alpine@sha256:91b27804074a0bacea298707f016911e60cf0cdbc6c7bf5ccacb5f0606d18d60
 
-# pixa is CGO/libvips: the type-aware linters compile every package, so
-# this image needs the same C libraries the build does.
-RUN apk add --no-cache build-base vips-dev libheif-dev pkgconfig
-
 WORKDIR /src
 
-# Modules first for layer caching; go.mod/go.sum settle this layer's
+# pixa is CGO/libvips: the type-aware linters compile every package, so
-# result, so it may safely be reused between runs.
+# this image needs the same C libraries the build does. script/bootstrap
+# installs them and downloads the Go modules. Only script/, go.mod and
+# go.sum are copied first; they settle this layer's result, so it may
+# safely be reused between runs.
+COPY script/ ./script/
 COPY go.mod go.sum ./
-RUN go mod download
+RUN script/bootstrap
 
 COPY . .
 

TODO.md

@@ -30,6 +30,14 @@ exhaustion
 
 # Completed Steps
 
+- 2026-09-29 Dockerfiles install through `script/bootstrap` (closes #95): the
+  `Dockerfile` lint and build stages and `Dockerfile.lint` copy `script/`,
+  `go.mod` and `go.sum`, then run `script/bootstrap` in place of their own
+  `apk add` lines, so the build dependencies are listed in one place;
+  `script/bootstrap` now also installs a C compiler when `gcc` is missing; the
+  build uses `-trimpath` and `-s -w` and keeps `CGO_ENABLED=1` for govips;
+  `ARG VERSION` sits just above the build, so a new version reruns neither
+  `script/bootstrap` nor the tests.
 - 2026-09-29 migrations at the path `REPO_POLICIES.md` sets (closes #96): the
   migration files moved, contents unchanged, from `internal/database/schema/`
   to `internal/db/migrations/` as `000_migration.sql` and `001_schema.sql`; the

script/bootstrap

@@ -5,8 +5,10 @@
 # or apk (detected in that order); assumes NOTHING is present (not git,
 # make, or go). The linter is never installed on the host: golangci-lint
 # runs only inside a container, Dockerfile.lint or the Dockerfile lint
-# stage (see script/lint). CGO image libraries (pkg-config, vips,
+# stage (see script/lint). A C compiler and the CGO image libraries
-# libheif) are installed for the govips bindings.
+# (pkg-config, vips, libheif) are installed for the govips bindings.
+# Both Dockerfiles run this script too, so their build dependencies are
+# the ones listed here.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
@@ -53,6 +55,11 @@ missing() {
 
 # CGO dependencies for govips (image processing)
 ensure_cgo_deps() {
+    # cgo compiles with gcc on Linux; build-base and build-essential
+    # also bring the C library headers.
+    if missing gcc; then
+        pkg_install gcc build-essential gcc build-base
+    fi
     if missing pkg-config; then
         pkg_install pkg-config pkg-config pkg-config pkgconfig
     fi