netwatch/Dockerfile

# The one image netwatch ships: nginx serves the built frontend and
# passes /api/, /.well-known/healthcheck and /metrics to netwatch-server,
# the Go backend, which runs in the same container on loopback only.
# bin/entrypoint.sh starts and watches both.
#
# The lint and test phases are the gates: `make lint` (script/lint)
# builds the lint stage alone and `make test` (script/test) the test
# stage alone, and the builder stage depends on both, so the image
# cannot be built unless they pass. Each covers the frontend as well,
# through a copy from a node stage. Inside them each tool is invoked
# directly, never through make or script/, whose lint and test are
# themselves docker builds.

# Frontend lint stage: eslint with the rules in eslint.config.js. The
# lint phase below runs it.
# node:22-alpine as of 2026-02-22
FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS frontend-lint
WORKDIR /app
COPY package.json yarn.lock ./
RUN yarn install --frozen-lockfile
COPY . .
RUN yarn eslint .

# Lint phase: golangci-lint over the backend with backend/.golangci.yml,
# and eslint through the copy from frontend-lint at the end. The
# golangci/golangci-lint image ships Go and the linter.
# golangci/golangci-lint:v2.14.0, 2026-09-24
FROM golangci/golangci-lint@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f AS lint
WORKDIR /src
COPY backend/go.mod backend/go.sum ./
RUN go mod download
COPY backend/ .
RUN golangci-lint run --config .golangci.yml ./...
# Nothing is wanted from frontend-lint; the copy is what makes this
# phase run it.
COPY --from=frontend-lint /app/yarn.lock /dev/null

# Frontend stage: the unit tests in test/unit/, then the production
# build into dist/, which the runtime stage serves. The test phase below
# runs it. The tests print a dot each; if any fails, they run again with
# every test listed, and the step fails even if that run passes.
# NODE_OPTIONS chooses the reporter because yarn adds its arguments
# after the test files, where node would take a reporter option for one
# more file.
# node:22-alpine as of 2026-02-22
FROM node@sha256:e4bf2a82ad0a4037d28035ae71529873c069b13eb0455466ae0bc13363826e34 AS frontend
WORKDIR /app
COPY package.json yarn.lock ./
RUN yarn install --frozen-lockfile
# vite.config.js reads the commit for the page's footer with git.
RUN apk add --no-cache git
COPY . .
RUN NODE_OPTIONS=--test-reporter=dot timeout 90 yarn --silent run test || \
    { echo "--- Rerunning with every test listed for details ---"; \
      NODE_OPTIONS=--test-reporter=spec timeout 90 yarn --silent run test; \
      exit 1; }
RUN yarn build

# Test phase: the backend's tests with the race detector and coverage,
# and the frontend's through the copy from the frontend stage at the
# end. -race needs cgo and so a C compiler, which the Debian Go image
# ships and the alpine one does not. -timeout 90s is a backstop above
# the 60-second cap on the suite. The rerun with -v only shows details:
# the step fails however it ends, because the first run already failed.
# Go's module and build caches are in memory (tmpfs) for the go test
# step alone, so the image make test tags does not carry them and the
# build spends no time writing them into it. They start empty on every
# build, so no stored test result can stand in for a run.
# golang:1.25.7-trixie, 2026-10-07
FROM golang@sha256:2b174ffcf56c7ad0c47d30d2630693265639ddf2a5141149c2da34db921791b4 AS test
WORKDIR /src
COPY backend/ .
RUN --mount=type=tmpfs,target=/go/pkg/mod \
    --mount=type=tmpfs,target=/root/.cache/go-build \
    go test -timeout 90s -race -cover ./... || \
    { echo "--- Rerunning with -v for details ---"; \
      go test -timeout 90s -race -v ./...; exit 1; }
# Nothing is wanted from the frontend stage; the copy is what makes
# this phase run its tests.
COPY --from=frontend /app/yarn.lock /dev/null

# Backend build stage. Nothing is wanted from the two phases; the copies
# are what make BuildKit build them first, so this stage cannot run
# unless lint and test passed.
# golang:1.25-alpine (2026-02-27)
FROM golang@sha256:f6751d823c26342f9506c03797d2527668d095b0a15f1862cddb4d927a7a4ced AS builder
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 backend/go.mod backend/go.sum backend/
RUN cd backend && go mod download
COPY . .

# backend/script/build is the one definition of the build command:
# CGO_ENABLED=0 go build -trimpath -ldflags "-s -w -X main.Version=..."
# It reads VERSION from the environment.
#
# The version is the VERSION build argument when one is given, otherwise
# `git describe --tags --always` on the .git in the build context: the
# tag on a tagged commit, tag-N-gHASH on a commit after one, the short
# commit when no tag is reachable. With .git present, a version that is
# still empty, dev or unknown fails the build: git is missing or could
# not read the checkout.
ARG VERSION
RUN version="${VERSION:-$(git describe --tags --always)}"; \
    if [ -e .git ]; then \
        case "$version" in ""|dev|unknown) \
            echo "version is '$version' although .git is present" >&2; \
            exit 1 ;; \
        esac; \
    fi; \
    VERSION="$version" backend/script/build

# Runtime stage, and the last one: a plain `docker build .` builds it
# and the stages it copies from, the two phases included.
# nginx:stable-alpine as of 2026-02-22
FROM nginx@sha256:15e96e59aa3b0aada3a121296e3bce117721f42d88f5f64217ef4b18f458c6ab

# netwatch-server runs as this user, which owns the report directory.
# nginx keeps the image's own arrangement: its main process runs as
# root, its worker processes as the nginx user.
RUN addgroup -g 1000 -S netwatch && \
    adduser -u 1000 -S netwatch -G netwatch

# At start-up the nginx image renders every template here into
# conf.d; bin/entrypoint.sh says how.
RUN rm /etc/nginx/conf.d/default.conf
COPY nginx.conf /etc/nginx/templates/netwatch.conf.template
COPY security-headers.conf /etc/nginx/security-headers.conf
COPY --from=frontend /app/dist /usr/share/nginx/html
COPY --from=builder /src/backend/netwatch-server /usr/local/bin/netwatch-server
COPY bin/entrypoint.sh /usr/local/bin/entrypoint.sh

# bin/entrypoint.sh creates DATA_DIR at start and gives it and /data to
# the netwatch user, whatever is mounted there.
ENV DATA_DIR=/data/reports
VOLUME /data

# The default public port; PORT changes it.
EXPOSE 8080

# Requests the backend's health check through nginx, on the port from
# PORT, so it fails unless both answer. upaas reads the result 60
# seconds after a deploy and fails the deploy unless it is healthy.
HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
    CMD wget -q -O /dev/null "http://127.0.0.1:${PORT:-8080}/.well-known/healthcheck"

# The nginx image stops its container with SIGQUIT; the entrypoint
# acts on TERM and INT.
STOPSIGNAL SIGTERM
ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]