webhooker/Dockerfile

# Stylesheet stages. static/css/tailwind.css is generated, by this pinned
# tailwindcss, from static/css/input.css and the files its @source lines
# name. `make css` (script/css) writes it out from the css-output stage.
# The css-check stage fails when the committed file differs from what is
# generated; `make check` runs it, and so does the build stage below.
#
# tailwindcss v4.2.1 standalone CLI, released 2026-02-23: one binary per
# architecture, each pinned by its sha256 from the release's sha256sums.txt.
# debian:bookworm-slim, 2026-10-02: the binary needs glibc.
FROM debian:bookworm-slim@sha256:3783cc01769c7b2b1b83a5c5ad96c815348e28ed7da68e2e3687004faa906251 AS tailwind-amd64
ADD --checksum=sha256:39e8d4e24b3c83b0a6e69e100a972fbc75d5fef8dce47b3ddac3cf92dea81fe3 --chmod=755 \
    https://github.com/tailwindlabs/tailwindcss/releases/download/v4.2.1/tailwindcss-linux-x64 /usr/local/bin/tailwindcss

FROM debian:bookworm-slim@sha256:3783cc01769c7b2b1b83a5c5ad96c815348e28ed7da68e2e3687004faa906251 AS tailwind-arm64
ADD --checksum=sha256:d87e6486bb3f70b04ef1dcaacc4ee6548a5a15fbf521b31bc24d2c774f68a951 --chmod=755 \
    https://github.com/tailwindlabs/tailwindcss/releases/download/v4.2.1/tailwindcss-linux-arm64 /usr/local/bin/tailwindcss

# TARGETARCH, set by docker, is the architecture being built for.
FROM tailwind-${TARGETARCH} AS css
WORKDIR /src
COPY . .
RUN tailwindcss -i static/css/input.css -o /out/tailwind.css --minify

FROM scratch AS css-output
COPY --from=css /out/tailwind.css /

# Both files are split after each "}", one rule per line, so that when they
# differ the diff shows the rules that differ.
FROM css AS css-check
RUN sed 's/}/}\n/g' static/css/tailwind.css > /tmp/committed.css \
    && sed 's/}/}\n/g' /out/tailwind.css > /tmp/generated.css \
    && diff -U0 /tmp/committed.css /tmp/generated.css || { \
        echo "static/css/tailwind.css is not what make css generates; run make css" >&2; \
        exit 1; \
    }

# JavaScript lint stages: ESLint, at the version package.json and yarn.lock
# pin, checks static/js/ against eslint.config.mjs. js-deps installs it, and
# prettier for the Markdown stages below. The lint phase below runs js-lint.
#
# The image's own corepack runs the yarn that package.json's packageManager
# field names, yarn 4.18.1 (released 2026-09-24), and checks it against the
# hash there. The image also ships yarn 1, which `corepack enable yarn`
# replaces.
# node:24.21.0-alpine (LTS), 2026-09-18
FROM node:24.21.0-alpine@sha256:ebfe2f90462722a7a4de65e91990e97fe0d401c70e0e762c5b53302f905ec1c1 AS js-deps
WORKDIR /src
COPY package.json yarn.lock .yarnrc.yml ./
RUN corepack enable yarn && yarn install --immutable --mode=skip-build

FROM js-deps AS js-lint
COPY . .
RUN --network=none node_modules/.bin/eslint static/js

# Markdown stages: prettier, at the version package.json and yarn.lock pin,
# formats every Markdown file in the tree with the settings in .prettierrc.
# `make fmt` (script/fmt) writes the formatted files out from markdown-output.
# markdown-check fails on any file prettier would change; `make fmt-check`
# runs it, and so does the build stage below.
FROM js-deps AS markdown
COPY . .
RUN --network=none node_modules/.bin/prettier --write '**/*.md' \
    && mkdir /out \
    && find . -name '*.md' ! -path './node_modules/*' -exec cp -p --parents {} /out \;

FROM scratch AS markdown-output
COPY --from=markdown /out /

FROM js-deps AS markdown-check
COPY . .
RUN --network=none node_modules/.bin/prettier --check '**/*.md'

# Lint phase: the Go formatting check and golangci-lint over the Go code,
# and ESLint over static/js/ through the copy from js-lint at the end.
# `make lint` (script/lint) builds this stage alone; the build stage below
# depends on it.
#
# golangci/golangci-lint:v2.14.0 (Debian-based), 2026-09-24
# Using Debian-based image because mattn/go-sqlite3 (CGO) does not
# compile on Alpine musl (off64_t is a glibc type).
FROM golangci/golangci-lint:v2.14.0@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f AS lint

WORKDIR /src

# Copy go mod files first for better layer caching
COPY go.mod go.sum ./
RUN go mod download

COPY . .

# gofmt and golangci-lint are invoked directly rather than through `make
# fmt-check` and `make lint`, which are themselves docker builds and would
# need a docker daemon inside this one. The Markdown half of `make
# fmt-check` is the markdown-check stage above.
RUN if [ -n "$(gofmt -s -l .)" ]; then echo "gofmt needed on:"; gofmt -s -l .; exit 1; fi

# static/static.go embeds the Alpine.js file this extracts from 3p/; without
# it the static package does not compile and cannot be linted.
RUN script/assets

# The golangci-lint steps run with --network=none. `golangci-lint config
# verify` is documented as fetching its JSON schema over HTTPS; this pinned
# image resolves the schema without any network, and --network=none enforces
# that. It also proves no linter reaches out at analysis time.
#
# `run` silently ignores config keys it does not recognize, so a typo would
# disable a setting without a word. `config verify` is what catches that.
RUN --network=none golangci-lint config verify --config .golangci.yml
# --build-tags browser also lints the browser test, which is built only with
# that tag (make test-browser).
RUN --network=none golangci-lint run --config .golangci.yml --build-tags browser ./...

# Nothing is wanted from js-lint; the copy is what makes this phase run it.
COPY --from=js-lint /src/yarn.lock /dev/null

# Test phase. -race needs cgo and so a C compiler, which the Debian Go image
# ships and the alpine one does not. `make test` (script/test) builds this
# stage alone; the build stage below depends on it.
#
# golang:1.26.1-bookworm (Debian-based), 2026-03-17
FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a3492282a6c820bf4755fd64a4 AS test

WORKDIR /src

COPY go.mod go.sum ./
RUN go mod download

COPY . .

# static/static.go embeds the Alpine.js file this extracts from 3p/.
RUN script/assets

# -timeout applies to each package on its own, so 90s has only to clear the
# slowest one. -p 4 -parallel 8 keep the run under 2 GB of memory: at most
# four test binaries build or run at once, each with at most eight parallel
# tests. Under -race every test binary and every link costs a few hundred MB,
# so the defaults (one per core) add up to several GB on a many-core host.
#
# The first run has no -v: go test then prints one result line per package,
# with its coverage, and for a package that fails, everything its tests
# wrote. Verbose output from the whole suite passes the 2 MiB at which the
# Docker build cuts off a step's log, so on a failure only the tests that
# failed run again, with -v. go test reports a failed test as a line starting
# "--- FAIL: TestName" (a failed subtest's line is indented, and reruns with
# its parent) and a failed package as "FAIL<tab>package/path<tab>...". A
# failure that names no test, such as a build error or a timeout, is already
# shown in full, so there is nothing to rerun. The step fails after the rerun
# whatever its result: the first run already showed the suite is broken.
#
# TMPDIR, where the tests keep their SQLite databases, is a tmpfs: SQLite
# waits for the disk at every commit, and on a busy host that waiting was
# about 40% of the slowest package's run time. GOTMPDIR keeps go's own
# build files, the test binaries among them, on disk.
#
# bash with pipefail, so that the first run's status is go test's, not tee's.
SHELL ["/bin/bash", "-o", "pipefail", "-c"]
RUN --mount=type=tmpfs,target=/tmp/tests,size=512m \
    export TMPDIR=/tmp/tests GOTMPDIR=/tmp; \
    go test -race -cover -p 4 -parallel 8 -timeout 90s ./... 2>&1 | tee /tmp/go-test.log && exit 0; \
    tests="$(awk '/^--- FAIL: / { print $3 }' /tmp/go-test.log | paste -s -d '|' -)"; \
    packages="$(awk '/^FAIL\t/ { print $2 }' /tmp/go-test.log)"; \
    if [ -n "$tests" ]; then \
        echo "--- Rerunning the failed tests with -v for details ---"; \
        go test -race -v -p 4 -parallel 8 -timeout 90s -run "^($tests)\$" $packages; \
    fi; \
    exit 1

# Build stage
# golang:1.26.1-bookworm (Debian-based), 2026-03-17
# Using Debian-based image because gorm.io/driver/sqlite pulls in
# mattn/go-sqlite3 (CGO), which does not compile on Alpine musl. The image
# ships git and make, which the version step below uses.
FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a3492282a6c820bf4755fd64a4 AS builder

# Nothing is wanted from the lint and test phases or from the stylesheet and
# Markdown checks; the copies are what make BuildKit build them first, so
# this stage cannot run unless they all passed.
COPY --from=lint /src/go.sum /dev/null
COPY --from=test /src/go.sum /dev/null
COPY --from=css-check /out/tailwind.css /dev/null
COPY --from=markdown-check /src/yarn.lock /dev/null

# A build context sent as a tar archive keeps its files' owners, and git
# refuses to read a checkout owned by another user. Trust this one
# whoever owns it.
RUN git config --system --add safe.directory /build

WORKDIR /build

# Copy go mod files first for better layer caching
COPY go.mod go.sum ./
RUN go mod download

COPY . .

# Version stamped into the binary: the VERSION build arg when one is
# given, otherwise what script/version derives from the .git the build
# context carries, so any `docker build .` of a clone stamps its commit.
# With neither, as from a source tarball, it is "unknown".
ARG VERSION

# A context that carries .git must not stamp an empty version, "dev" or
# "unknown": that means git is missing here or could not read the
# checkout, and the image could not be traced back to its commit.
RUN version="$(make version VERSION="$VERSION")"; \
    if [ -e .git ]; then \
        case "$version" in ""|dev|unknown) \
            echo "version is '$version' although .git is present" >&2; \
            exit 1 ;; \
        esac; \
    fi

# Builds through the Makefile's build target, which runs script/assets
# (Alpine.js, extracted from its tarball in 3p/) first.
RUN make build VERSION="$VERSION"

# Rebuild with static linking for Alpine runtime.
# make build already verified compilation.
# The CGO binary from `make build` is dynamically linked against glibc,
# which doesn't exist on Alpine (musl). Rebuild with static linking so
# the binary runs on Alpine without glibc.
#
# The static flags go in through GO_LDFLAGS rather than a -ldflags of
# their own: the build target composes them with the -X that stamps the
# version, so this relink cannot silently drop the stamp.
RUN CGO_ENABLED=1 make build VERSION="$VERSION" GO_LDFLAGS='-extldflags "-static"'

# Runtime stage
# alpine:3.21, 2026-03-17
FROM alpine:3.21@sha256:c3f8e73fdb79deaebaa2037150150191b9dcbfba68b4a46d70103204c53f4709

# su-exec 0.2-r3 (Alpine 3.21), 2026-09-29: the entrypoint runs the app
# as webhooker with it.
RUN apk --no-cache add ca-certificates su-exec=0.2-r3

# Create non-root user
RUN addgroup -g 1000 -S webhooker && \
    adduser -u 1000 -S webhooker -G webhooker

WORKDIR /app

# Copy binary from builder
COPY --from=builder /build/bin/webhooker /app/webhooker

# Not under /app, which belongs to webhooker: this script runs as root.
COPY deploy/docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh

# Create data directory for all SQLite databases (main app DB +
# per-webhook event DBs). DATA_DIR defaults to /var/lib/webhooker.
RUN mkdir -p /var/lib/webhooker

RUN chown -R webhooker:webhooker /app /var/lib/webhooker

# No USER: the entrypoint starts as root to make the data directory
# webhooker's, then runs the app as webhooker.

EXPOSE 8080

# The binary defaults BIND_ADDRESS to 127.0.0.1, which is right for a
# bare host: the cleartext listener serves the admin UI and the
# unauthenticated receiver, so it must not appear on every interface
# of a machine that configured nothing. A container is the other case.
# Its network namespace is already the isolation boundary, so binding
# every address inside it exposes nothing; what decides exposure is
# the publish flag, and `-p 127.0.0.1:8080:8080` is the operator's
# control there. Shipping the image on loopback would buy no security
# and would make the process unreachable through its own published
# port.
ENV BIND_ADDRESS=0.0.0.0

HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD wget --no-verbose --tries=1 --spider http://localhost:8080/.well-known/healthcheck || exit 1

ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
CMD ["/app/webhooker"]