webhooker/Dockerfile

# Lint stage
# golangci/golangci-lint:v2.12.2 (Debian-based), 2026-08-07
# 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:v2.12.2@sha256:5cceeef04e53efe1470638d4b4b4f5ceefd574955ab3941b2d9a68a8c9ad5240 AS lint

RUN apt-get update && apt-get install -y --no-install-recommends make && rm -rf /var/lib/apt/lists/*

WORKDIR /src

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

# Copy source code. In CI the context also carries .ci-fingerprint, whose
# value changes with every commit that touches the build context (see
# .gitea/workflows/check.yml). That invalidates this layer, so the checks
# below cannot report success by replaying a cached pass. Do not add it to
# .dockerignore.
COPY . .

# Run formatting check and linter. golangci-lint is invoked directly rather
# than through `make lint`: this stage is already the pinned linter image, and
# script/lint is a wrapper that builds Dockerfile.lint, so calling it here
# would need a docker daemon inside the build. Keep these steps in step with
# Dockerfile.lint, including --network=none (see its header for why).
RUN make fmt-check
RUN --network=none golangci-lint config verify --config .golangci.yml
RUN --network=none golangci-lint run --config .golangci.yml ./...

# 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.
FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a3492282a6c820bf4755fd64a4 AS builder

# Depend on lint stage passing
COPY --from=lint /src/go.sum /dev/null

# jq is a runtime dependency of script/ci-mark-superseded, which the test
# suite executes. git is what script/version derives the version with.
RUN apt-get update && apt-get install -y --no-install-recommends make curl ca-certificates jq git && rm -rf /var/lib/apt/lists/*

WORKDIR /build

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

# Copy source code, including the .ci-fingerprint cache barrier described in
# the lint stage above.
COPY . .

# Run tests and build. Both first run script/assets, which extracts Alpine.js
# from its tarball in 3p/.
RUN make test

# 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".
#
# Declared here, below the test step, so a changed version does not
# invalidate its cached layer.
ARG VERSION

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

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"]