diff --git a/Dockerfile b/Dockerfile index b2d7c80..9e5b100 100644 --- a/Dockerfile +++ b/Dockerfile @@ -1,12 +1,16 @@ -# Every stage declares ARG CACHEBUST first: script/ passes a new value -# on every build, which reruns every RUN step after it. The steps that -# compile mount Go's build cache, which survives from build to build. +# In every stage ARG CACHEBUST comes right after the steps that install +# system packages and download Go's modules, or right after FROM in a +# stage with neither, and every step that lints, tests or compiles +# comes after it. script/ passes a new value on every build, which +# reruns every RUN step after it. Docker keeps the layers above it +# until the base image, their own lines or go.mod and go.sum change. +# The steps that compile mount Go's build cache, and golangci-lint run +# also mounts golangci-lint's; both survive from build to build. # Lint phase. script/lint builds it alone. The linter is run directly: # `make lint` and script/lint are themselves a docker build. # golangci/golangci-lint:v2.14.0, 2026-10-15 FROM golangci/golangci-lint@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f AS lint -ARG CACHEBUST # The linter compiles every package, and govips needs the libvips # headers for that. REPO_POLICIES.md has the lint phase install them @@ -18,25 +22,29 @@ RUN apt-get update \ WORKDIR /src COPY go.mod go.sum ./ RUN go mod download +ARG CACHEBUST COPY . . RUN --mount=type=cache,target=/root/.cache/go-build \ + --mount=type=cache,target=/root/.cache/golangci-lint \ golangci-lint run --config .golangci.yml ./... # Test phase. script/test builds it alone. -race needs cgo and so a C # compiler, which the Debian Go image ships and the alpine one does not. # golang:1.25.4-trixie, 2026-10-15 FROM golang@sha256:a02d35efc036053fdf0da8c15919276bf777a80cbfda6a35c5e9f087e652adfc AS test -ARG CACHEBUST + +# govips compiles against the libvips and libheif headers, and the tests +# need libvips' JPEG XL support and libheif's AVIF encoder. Debian's +# libvips-dev brings all of them, the encoder as a recommended package, +# so recommended packages are installed here. +RUN apt-get update \ + && apt-get install -y libvips-dev \ + && rm -rf /var/lib/apt/lists/* WORKDIR /src - -# script/bootstrap --cgo installs the build dependencies (the libvips -# and libheif headers, and libvips' JPEG XL support, which the tests -# need) and downloads the Go modules. -COPY script/ ./script/ COPY go.mod go.sum ./ -RUN script/bootstrap --cgo - +RUN go mod download +ARG CACHEBUST COPY . . # Without -v first; on a failure, again with -v for the details, and @@ -52,22 +60,23 @@ RUN --mount=type=cache,target=/root/.cache/go-build \ go test -count=1 -timeout 90s -race -parallel 4 -v ./...; exit 1; } # Build stage. Nothing is wanted from the two phases above: these copies -# make BuildKit build them first, so this stage runs only when lint and -# test passed. +# make BuildKit build them first, so nothing after them runs unless lint +# and test passed. # golang:1.25.4-alpine3.22, 2026-02-25; the runtime stage uses Alpine 3.22 too FROM golang:1.25.4-alpine3.22@sha256:d3f0cf7723f3429e3f9ed846243970b20a2de7bae6a5b66fc5914e228d831bbb AS builder + +# git for the version, and for govips a C compiler, pkg-config and the +# libvips and libheif headers +RUN apk add --no-cache git build-base pkgconfig vips-dev libheif-dev + +WORKDIR /src +COPY go.mod go.sum ./ +RUN go mod download ARG CACHEBUST COPY --from=lint /src/go.sum /dev/null COPY --from=test /src/go.sum /dev/null -WORKDIR /src - -# Build dependencies, git among them, and Go modules, as in the test -# phase -COPY script/ ./script/ -COPY go.mod go.sum ./ -RUN script/bootstrap --cgo # A tar-stream context keeps the sender's file owners, which git refuses. RUN git config --system --add safe.directory /src @@ -102,7 +111,6 @@ RUN --mount=type=cache,target=/root/.cache/go-build \ # the libvips and musl it was built with. # alpine:3.22, 2026-10-08 FROM alpine:3.22@sha256:5291449c3df73caf6ed85e649dec1b9e818b39a5d8c871e97afc13e9cd5e8fa8 -ARG CACHEBUST # Install runtime dependencies only. vips-jxl is libvips' JPEG XL # support, without which pixad does not start. @@ -113,6 +121,7 @@ RUN apk add --no-cache \ ca-certificates \ tzdata \ su-exec +ARG CACHEBUST # Copy binary from builder COPY --from=builder /pixad /usr/local/bin/pixad diff --git a/README.md b/README.md index 6338c40..44c41ea 100644 --- a/README.md +++ b/README.md @@ -825,19 +825,24 @@ provide: `script/precommit` Every `docker build` in these scripts passes a new value of the `CACHEBUST` -build argument, which every stage of the `Dockerfile` declares first, so every -`RUN` step, the lint and test phases included, runs on every build instead of -coming from the build cache. Go's build cache is kept from build to build: the -steps that compile mount it, so a package whose inputs are unchanged is not -compiled again, and both `go test` runs pass `-count=1` so that no stored test -result is replayed. The `test` phase runs on the Debian Go image, with Debian's -libvips and libheif; the image pixa ships is built and runs on Alpine. -`script/check`, `script/cibuild`, `script/docker`, `script/lint`, `script/test`, -`script/setup` and `script/install-precommit` are the standard copies from -`sneak/prompts`, kept identical to them. `script/fmt` and `script/fmt-check` are -the standard copies with pixa's `gofmt` step kept before prettier. prettier -formats the markdown only, not the HTML templates, as it cannot parse a Go -template action inside a tag. +build argument, which every stage of the `Dockerfile` declares, so every `RUN` +step after that line, the lint and test steps included, runs on every build +instead of coming from the build cache. Above the line are the steps that +install system packages and download the Go modules; Docker keeps their layers +until the base image, the step itself, `go.mod` or `go.sum` changes. Go's build +cache is kept from build to build: the steps that compile mount it, so a package +whose inputs are unchanged is not compiled again, and both `go test` runs pass +`-count=1` so that no stored test result is replayed. The lint step also mounts +golangci-lint's cache, which reuses a package's findings only when its files, +those of the packages it imports, `go.mod`, `.golangci.yml` and the +golangci-lint version are all unchanged. The `test` phase runs on the Debian Go +image, with Debian's libvips and libheif; the image pixa ships is built and runs +on Alpine. `script/check`, `script/cibuild`, `script/docker`, `script/lint`, +`script/test`, `script/setup` and `script/install-precommit` are the standard +copies from `sneak/prompts`, kept identical to them. `script/fmt` and +`script/fmt-check` are the standard copies with pixa's `gofmt` step kept before +prettier. prettier formats the markdown only, not the HTML templates, as it +cannot parse a Go template action inside a tag. ## Load Test diff --git a/REPO_POLICIES.md b/REPO_POLICIES.md index 5b24098..1067698 100644 --- a/REPO_POLICIES.md +++ b/REPO_POLICIES.md @@ -1,6 +1,6 @@ --- title: Repository Policies -last_modified: 2026-10-15 +last_modified: 2026-10-18 --- This document covers repository structure, tooling, and workflow standards. Code @@ -159,8 +159,11 @@ style conventions are in separate documents: 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 golangci-lint cache, its - own `TMPDIR` and a digest-pinned binary, so neither is reachable. + org, in both directions. A container has its own `TMPDIR`, so the lock is + out of reach. The lint phase does keep golangci-lint's cache between check + builds (below), but it lints every checkout at `/src`, and a finding is + taken from that cache only for the same files, settings and golangci-lint + version. - **Any build that runs checks is given a new `CACHEBUST` value.** Docker invalidates a `COPY` layer only when the copied content changes, so on an @@ -170,15 +173,21 @@ style conventions are in separate documents: id, so no two builds share a value, not even the three in one `script/cibuild`. `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. Every - stage of the `Dockerfile` declares `ARG CACHEBUST` as its first line after - `FROM`, and a new value reruns every `RUN` step after that line; `COPY` steps - are compared by content and need nothing. A stage without the `ARG` line is - served from cache on an unchanged tree, so a repository re-vendors the scripts - and adds the `ARG` lines in one commit. The scripts do not pass `--no-cache`: - it reruns every step too, but it also empties every cache mount, and Go's - build cache, which the canonical Go `Dockerfile` below mounts so that compiled - packages survive between check builds, would start empty every time. A bare + two gate phases and `script/fmt-check`, and builds no image of its own. In + every stage of the `Dockerfile`, `ARG CACHEBUST` comes right after the steps + that install system packages and download Go's modules, or right after `FROM` + in a stage with neither, and every step that lints, tests or compiles comes + after it. A step that installs anything else as well, such as a + `script/bootstrap` that also installs node packages, comes after it too. A new + value reruns every `RUN` step after that line; `COPY` steps are compared by + content and need nothing. Docker keeps the layers above the line until the + base image, their own lines or the files they copy change. A stage without the + `ARG` line is served from cache on an unchanged tree, so a repository + re-vendors the scripts and adds the `ARG` lines in one commit. The scripts do + not pass `--no-cache`: it reruns every step too, but it also builds the layers + above the line again and empties every cache mount, so Go's build cache and + golangci-lint's, which the canonical Go `Dockerfile` below mounts so that they + survive between check builds, would start empty every time. 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 @@ -194,19 +203,25 @@ style conventions are in separate documents: `Dockerfile`: ```dockerfile - # Every stage declares ARG CACHEBUST first: script/ passes a new value - # on every build, which reruns every RUN step after it. The steps that - # compile mount Go's build cache, which survives from build to build. + # In every stage ARG CACHEBUST comes right after the steps that install + # system packages and download Go's modules, or right after FROM in a + # stage with neither, and every step that lints, tests or compiles + # comes after it. script/ passes a new value on every build, which + # reruns every RUN step after it. Docker keeps the layers above it + # until the base image, their own lines or go.mod and go.sum change. + # The steps that compile mount Go's build cache, and golangci-lint run + # also mounts golangci-lint's; both survive from build to build. # Lint phase # golangci/golangci-lint:v2.x.x, YYYY-MM-DD FROM golangci/golangci-lint@sha256:... AS lint - ARG CACHEBUST WORKDIR /src COPY go.mod go.sum ./ RUN go mod download + ARG CACHEBUST COPY . . RUN --mount=type=cache,target=/root/.cache/go-build \ + --mount=type=cache,target=/root/.cache/golangci-lint \ golangci-lint run --config .golangci.yml ./... # Test phase. -race needs cgo and so a C compiler, which the Debian Go @@ -214,10 +229,10 @@ style conventions are in separate documents: # cache also holds test results, which go test would otherwise replay. # golang:1.x, YYYY-MM-DD FROM golang@sha256:... AS test - ARG CACHEBUST WORKDIR /src COPY go.mod go.sum ./ RUN go mod download + ARG CACHEBUST COPY . . RUN --mount=type=cache,target=/root/.cache/go-build \ go test -count=1 -timeout 90s -race -cover ./... || \ @@ -225,19 +240,19 @@ style conventions are in separate documents: go test -count=1 -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. + # are what make BuildKit build them first, so nothing after them can + # run unless lint and test passed. # golang:1.x-alpine, YYYY-MM-DD FROM golang@sha256:... AS builder - ARG CACHEBUST - COPY --from=lint /src/go.sum /dev/null - COPY --from=test /src/go.sum /dev/null RUN apk add --no-cache git - # A tar-stream context keeps the sender's file owners, which git refuses. - RUN git config --system --add safe.directory /src WORKDIR /src COPY go.mod go.sum ./ RUN go mod download + ARG CACHEBUST + COPY --from=lint /src/go.sum /dev/null + COPY --from=test /src/go.sum /dev/null + # A tar-stream context keeps the sender's file owners, which git refuses. + RUN git config --system --add safe.directory /src COPY . . # The VERSION build arg when one is given, otherwise @@ -274,16 +289,26 @@ style conventions are in separate documents: - 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. - - Only Go's build cache is mounted (`/root/.cache/go-build`, where Go keeps - it for root), and only on the steps that compile: `golangci-lint run`, - both `go test` runs and `go build`. It keeps compiled packages between - check builds, and Go reuses one only when all its inputs are unchanged, so - it saves the compile without skipping a check. Nothing else is kept: - golangci-lint's own cache would replay stored findings in place of a lint - run, and Go builds from whatever files a kept module cache holds without - checking them again (only `go mod verify` does), so a file changed there - would go unnoticed. Go's build cache also holds test results, which is why - both `go test` runs carry `-count=1`. + - Check builds keep these, and none of them can hand back a stale result: + - The layers above `ARG CACHEBUST`: the system packages and Go's + modules. Docker installs the packages again when the base image or the + install line changes, and downloads the modules again when `go.mod` or + `go.sum` changes. Go checks every module against `go.sum` as it + downloads it, and no later build can change a kept layer. The modules + are kept in a layer rather than a cache mount because a cache mount is + shared by every build on the host, and Go builds from whatever files + it holds without checking them again (only `go mod verify` does), so a + file changed there would go unnoticed. + - Go's build cache (`/root/.cache/go-build`, where Go keeps it for + root), mounted on the steps that compile: `golangci-lint run`, both + `go test` runs and `go build`. Go reuses a compiled package only when + all its inputs are unchanged. The cache also holds test results, which + is why both `go test` runs carry `-count=1`. + - golangci-lint's cache (`/root/.cache/golangci-lint`, where the pinned + image keeps it), mounted on `golangci-lint run`. golangci-lint reuses + a package's findings only when the package's files and those of every + package it imports, `go.mod`, the linters and their settings in + `.golangci.yml`, and the golangci-lint version are all unchanged. - If the project uses `//go:embed` directives that reference build artifacts (e.g. a web frontend compiled in a separate stage), the lint phase must create placeholder files so the embed directives resolve. Example: @@ -292,12 +317,20 @@ style conventions are in separate documents: in the lint phase. The `golangci/golangci-lint` image is Debian-based and has no `apk`, so install with `apt-get` under the Debian package name (`libvips-dev`, where alpine says `vips-dev`), and delete the package - lists in the same `RUN`, so the layer does not keep them: + lists in the same `RUN`, so the layer does not keep them. The test phase, + on the Debian Go image, installs the libraries its tests need the same + way. Either install goes right after `FROM`, above `ARG CACHEBUST`, so + Docker keeps it until the base image or the install line changes: ```dockerfile + FROM golangci/golangci-lint@sha256:... AS lint RUN apt-get update \ && apt-get install -y --no-install-recommends libvips-dev \ && rm -rf /var/lib/apt/lists/* + WORKDIR /src + COPY go.mod go.sum ./ + RUN go mod download + ARG CACHEBUST ``` - `.dockerignore` lets `.git` into the build context. It keeps out every git diff --git a/TODO.md b/TODO.md index 596940e..eef6301 100644 --- a/TODO.md +++ b/TODO.md @@ -30,6 +30,10 @@ P2: security: per-origin rate limiting # Completed Steps +- 2026-10-18 re-vendored from `sneak/prompts` commit `0653579` (closes #221): + each `Dockerfile` stage installs its system packages and downloads the Go + modules above `ARG CACHEBUST`, so check builds keep them, and the lint step + keeps golangci-lint's cache. - 2026-10-16 P1 security bug: the check that keeps pixa from fetching internal addresses refuses the local-use NAT64 range (`64:ff9b:1::/48`, RFC 8215) as it refuses `64:ff9b::/96`, and refuses an IPv6 address in the IPv4-compatible diff --git a/script/bootstrap b/script/bootstrap index 8fd0cbe..e3fe598 100755 --- a/script/bootstrap +++ b/script/bootstrap @@ -19,9 +19,8 @@ # CGO image libraries (pkg-config, vips # with its JPEG XL support, libheif) for # the govips bindings instead of Node: to -# compile pixa, in the Dockerfile's test -# phase and build stage, which format -# nothing +# compile pixa outside Docker, as +# `make build` does set -eu ROOT="$(cd "$(dirname "$0")/.." && pwd -P)" diff --git a/script/cibuild b/script/cibuild index 66fcca0..2656771 100755 --- a/script/cibuild +++ b/script/cibuild @@ -2,11 +2,12 @@ # script/cibuild: run the CI build. It bootstraps first: a CI runner # checks out and runs this and nothing else, and script/fmt-check runs # the formatter on the host, which a pristine checkout cannot do. -# A new CACHEBUST value reruns every RUN step, since a cached gate phase -# is a check that did not run; unlike --no-cache, it keeps Go's build cache. +# A new CACHEBUST value reruns every RUN step after the ARG CACHEBUST +# line, since a cached gate phase is a check that did not run; unlike +# --no-cache, it keeps the layers above that line and the cache mounts. # This relies on every stage of the Dockerfile declaring ARG CACHEBUST -# first; a stage without that line is served from cache on an unchanged -# tree, with no warning. +# before every step that lints, tests or compiles; a stage without that +# line is served from cache on an unchanged tree, with no warning. set -eu SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)" diff --git a/script/docker b/script/docker index 360037a..cc00d9c 100755 --- a/script/docker +++ b/script/docker @@ -1,11 +1,12 @@ #!/bin/sh # script/docker: build the Docker image tagged with the project name. # Identical in all repos; the tag comes from script/projectname. -# A new CACHEBUST value reruns every RUN step, since a cached gate phase -# is a check that did not run; unlike --no-cache, it keeps Go's build cache. +# A new CACHEBUST value reruns every RUN step after the ARG CACHEBUST +# line, since a cached gate phase is a check that did not run; unlike +# --no-cache, it keeps the layers above that line and the cache mounts. # This relies on every stage of the Dockerfile declaring ARG CACHEBUST -# first; a stage without that line is served from cache on an unchanged -# tree, with no warning. +# before every step that lints, tests or compiles; a stage without that +# line is served from cache on an unchanged tree, with no warning. set -eu SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)" diff --git a/script/lint b/script/lint index c4c459e..451a067 100755 --- a/script/lint +++ b/script/lint @@ -5,11 +5,13 @@ # make its answer untrustworthy. # # The phase is not the last stage in the file, so it is built only when -# --target names it. A new CACHEBUST value reruns every RUN step, since -# a cached lint layer is a lint that did not run; unlike --no-cache, it -# keeps Go's build cache. This relies on every stage of the Dockerfile -# declaring ARG CACHEBUST first; a stage without that line is served -# from cache on an unchanged tree, with no warning. +# --target names it. A new CACHEBUST value reruns every RUN step after +# the ARG CACHEBUST line, since a cached lint layer is a lint that did +# not run; unlike --no-cache, it keeps the layers above that line and +# the cache mounts. This relies on every stage of the Dockerfile +# declaring ARG CACHEBUST before every step that lints, tests or +# compiles; a stage without that line is served from cache on an +# unchanged tree, with no warning. # --output type=cacheonly writes no image, since nothing uses one. set -eu diff --git a/script/test b/script/test index a56c4a1..1622a11 100755 --- a/script/test +++ b/script/test @@ -3,11 +3,12 @@ # and this builds that phase alone, on the same terms as script/lint: # --target because a phase that is not the last stage is built only when # named, and a new CACHEBUST value because a cached test layer is a test -# that did not run; unlike --no-cache, it keeps Go's build cache. This -# relies on every stage of the Dockerfile declaring ARG CACHEBUST first; -# a stage without that line is served from cache on an unchanged tree, -# with no warning. --output type=cacheonly writes no image, since -# nothing uses one. +# that did not run; unlike --no-cache, it keeps the layers above the ARG +# CACHEBUST line and the cache mounts. This relies on every stage of the +# Dockerfile declaring ARG CACHEBUST before every step that lints, tests +# or compiles; a stage without that line is served from cache on an +# unchanged tree, with no warning. --output type=cacheonly writes no +# image, since nothing uses one. set -eu SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"