Add tested standalone distroless Flood variant

.gitea/workflows/build-distroless.yml

@@ -0,0 +1,71 @@
+name: Build Distroless Flood
+
+on:
+  workflow_dispatch:
+    inputs:
+      flood_version:
+        description: 'jesec/flood release tag'
+        required: true
+        default: 'v4.16.2'
+        type: string
+
+jobs:
+  build:
+    runs-on: kube
+    if: github.ref == 'refs/heads/main'
+    env:
+      DOCKER_BUILD_RECORD_UPLOAD: 'false'
+      DOCKER_BUILD_SUMMARY: 'false'
+    steps:
+      - name: Checkout code
+        uses: https://github.com/actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Fetch Flood release
+        env:
+          FLOOD_VERSION: ${{ github.event.inputs.flood_version }}
+        run: |
+          test -n "$FLOOD_VERSION" || { echo "flood_version is required" >&2; exit 1; }
+          git check-ref-format "refs/tags/$FLOOD_VERSION"
+          git init flood-repo
+          git -C flood-repo fetch --depth=1 https://github.com/jesec/flood.git "refs/tags/$FLOOD_VERSION"
+          git -C flood-repo checkout --detach FETCH_HEAD
+          cp Dockerfile.distroless flood-repo/Dockerfile.distroless
+          cp build/runtime-root.py flood-repo/.ci-runtime-root.py
+          cp tests/startup-distroless.cjs flood-repo/.ci-startup-distroless.cjs
+          printf '\n.git\n.github\n.env\n' >> flood-repo/.dockerignore
+
+      - name: Install Docker CLI
+        run: |
+          apt-get update
+          apt-get install -y --no-install-recommends docker.io
+          rm -rf /var/lib/apt/lists/*
+
+      - name: Log in to Docker Hub
+        uses: https://github.com/docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_TOKEN }}
+
+      - name: Set up temporary builder
+        uses: https://github.com/docker/setup-buildx-action@v3
+        with:
+          driver: docker-container
+          cache-binary: false
+          keep-state: false
+          cleanup: true
+
+      - name: Build and push to Docker Hub
+        uses: https://github.com/docker/build-push-action@v6
+        with:
+          context: ./flood-repo
+          file: ./flood-repo/Dockerfile.distroless
+          platforms: linux/amd64
+          pull: true
+          push: true
+          load: false
+          tags: docker.io/k2patel/floodui:distroless
+          labels: |
+            org.opencontainers.image.source=https://git.k2patel.in/k2patel/docker-flood-client
+            org.opencontainers.image.revision=${{ github.sha }}

Dockerfile.distroless

@@ -0,0 +1,27 @@
+# Alpine-built binaries and musl stay together; no shell/package manager in final image.
+ARG NODE_IMAGE=docker.io/node:24.18.1-alpine3.24
+FROM ${NODE_IMAGE} AS nodebuild
+WORKDIR /usr/src/app
+COPY . ./
+RUN npm install -g corepack && corepack enable && corepack install \
+    && pnpm install --frozen-lockfile
+RUN npm run build
+
+FROM ${NODE_IMAGE} AS runtime
+RUN apk add --no-cache mediainfo coreutils ca-certificates tzdata \
+    lddtreepax python3
+COPY .ci-runtime-root.py /build/runtime-root.py
+RUN python3 /build/runtime-root.py /runtime /usr/local/bin/node \
+    /usr/bin/mediainfo "$(command -v df)"
+COPY --from=nodebuild /usr/src/app/dist /runtime/usr/src/app/dist
+COPY --from=nodebuild /usr/src/app/package.json /runtime/usr/src/app/package.json
+COPY --from=nodebuild /usr/src/app/LICENSE /runtime/usr/src/app/LICENSE
+
+FROM scratch
+COPY --from=runtime /runtime/ /
+ENV NODE_ENV=production HOME=/root PATH=/usr/local/bin:/usr/bin:/bin
+WORKDIR /usr/src/app
+RUN --mount=type=bind,from=nodebuild,source=/usr/src/app/.ci-startup-distroless.cjs,target=/ci-startup.cjs ["/usr/local/bin/node", "/ci-startup.cjs"]
+VOLUME ["/server/db"]
+EXPOSE 3000
+ENTRYPOINT ["/usr/local/bin/node", "--enable-source-maps", "--use_strict", "dist/index.js", "--host=0.0.0.0", "--rundir=/server/"]

README.md

@@ -33,3 +33,23 @@ publishing; it does not start a torrent daemon.
 The entrypoint uses `npm run start`, matching upstream v4.16.2, while retaining
 `--host=0.0.0.0` and `--rundir=/server/`. The upstream combined rTorrent stage
 is deliberately excluded.
+
+## Distroless variant
+
+The manual **Build Distroless Flood** workflow publishes `k2patel/floodui:distroless`
+for the selected Flood release (default `v4.16.2`). It does not change `latest`.
+
+The Alpine 3.24-derived runtime contains Node 24.18.1, the bundled Flood server/UI,
+mediainfo, GNU df, their musl libraries, CA certificates and timezone data. The
+final image is built from scratch, with no shell, npm/pnpm, package manager,
+node_modules, source tree or build tools. It starts Node directly and remains
+separate from rTorrent. Root UID, port 3000, and `/server/db` stay compatible.
+
+Before publication, CI starts Flood inside the exact stripped filesystem and
+requires an HTTP 200 response; it also checks mediainfo and df can execute and
+that shell/package-manager binaries are absent. All builds run remotely, and
+the temporary builder/cache is removed afterward.
+
+Change only the Compose image tag to `k2patel/floodui:distroless`; keep existing
+mounts and connection settings. Revert to `latest` to roll back. A matching
+rTorrent Compose overlay is provided in the docker-rtorrent repository.

build/runtime-root.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""Assemble an Alpine-derived, shell-free runtime from an explicit ELF allowlist."""
+import os
+from pathlib import Path
+import shutil
+import subprocess
+import sys
+
+root = Path(sys.argv[1])
+root.mkdir(parents=True, exist_ok=True)
+
+copied = set()
+
+def copy(source):
+    source = Path(os.path.normpath(source))
+    if source in copied:
+        return
+    copied.add(source)
+    target = root / str(source).lstrip('/')
+    target.parent.mkdir(parents=True, exist_ok=True)
+    if source.is_symlink():
+        link = os.readlink(source)
+        if not target.is_symlink():
+            target.symlink_to(link)
+        # Preserve every hop, not just the final file in a multi-link chain.
+        copy(link if os.path.isabs(link) else source.parent / link)
+    elif source.is_dir():
+        target.mkdir(exist_ok=True)
+        for child in source.iterdir():
+            copy(child)
+    else:
+        shutil.copy2(source, target)
+
+for executable in sys.argv[2:]:
+    result = subprocess.run(['lddtreepax', '-l', executable], check=True, text=True, capture_output=True)
+    paths = result.stdout.splitlines()
+    if not paths or any(not p.startswith('/') or not Path(p).exists() for p in paths):
+        raise SystemExit(f'Unresolved runtime dependency for {executable}: {result.stdout}')
+    copy(executable)
+    for path in paths:
+        copy(path)
+
+# musl uses this file for nonstandard library directories (for example Lua).
+for search_path in Path('/etc').glob('ld-musl-*.path'):
+    copy(search_path)
+
+for data in ['/etc/ssl/certs/ca-certificates.crt', '/etc/ssl/cert.pem',
+             '/etc/ssl/openssl.cnf', '/usr/lib/ossl-modules', '/usr/share/zoneinfo',
+             '/etc/terminfo', '/usr/share/terminfo', '/etc/services', '/etc/protocols',
+             '/etc/alpine-release', '/etc/os-release']:
+    if Path(data).exists():
+        copy(data)
+for directory in ['tmp', 'root', 'myconfig', 'home/nfs_download/rsession', 'server/db', 'config', 'etc']:
+    (root / directory).mkdir(parents=True, exist_ok=True)
+os.chmod(root / 'tmp', 0o1777)
+(root / 'root/.rtorrent.rc').touch()
+(root / 'etc/passwd').write_text('root:x:0:0:root:/root:/sbin/nologin\n')
+(root / 'etc/group').write_text('root:x:0:\n')
+for forbidden in ['bin/sh', 'bin/bash', 'bin/busybox', 'sbin/apk', 'usr/bin/apk',
+                  'usr/bin/npm', 'usr/local/bin/npm', 'usr/bin/python3']:
+    assert not (root / forbidden).exists(), f'Unexpected runtime tool: {forbidden}'

tests/startup-distroless.cjs

@@ -0,0 +1,57 @@
+const {spawn, execFileSync} = require('node:child_process');
+const http = require('node:http');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+for (const file of ['/bin/sh', '/bin/bash', '/bin/busybox', '/sbin/apk', '/usr/local/bin/npm']) {
+  if (fs.existsSync(file)) throw new Error(`Unexpected runtime tool: ${file}`);
+}
+execFileSync('mediainfo', ['--Version'], {stdio: 'inherit'});
+execFileSync('df', ['--version'], {stdio: 'inherit'});
+const runDir = fs.mkdtempSync(path.join(os.tmpdir(), 'flood-smoke-'));
+const child = spawn(process.execPath, ['--enable-source-maps', '--use_strict', 'dist/index.js',
+  '--host=127.0.0.1', '--port=3000', `--rundir=${runDir}`],
+  {cwd: '/usr/src/app', stdio: 'inherit', detached: true});
+let startupError;
+child.on('error', error => { startupError = error; });
+const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
+const check = () => new Promise(resolve => {
+  const req = http.get('http://127.0.0.1:3000/', response => {
+    let bytes = 0;
+    response.on('data', chunk => { bytes += chunk.length; });
+    response.on('end', () => resolve(response.statusCode === 200 && bytes > 0));
+  });
+  req.setTimeout(1000, () => req.destroy());
+  req.on('error', () => resolve(false));
+});
+(async () => {
+  try {
+    const deadline = Date.now() + 60000;
+    while (Date.now() < deadline) {
+      if (startupError) throw startupError;
+      if (child.exitCode !== null || child.signalCode !== null) {
+        throw new Error(`Flood exited before serving HTTP: ${child.exitCode ?? child.signalCode}`);
+      }
+      if (await check()) {
+        console.log('Flood startup smoke test passed: HTTP 200 with response body');
+        return;
+      }
+      await sleep(500);
+    }
+    throw new Error('Flood did not serve HTTP within 60 seconds');
+  } catch (error) {
+    console.error(error);
+    process.exitCode = 1;
+  } finally {
+    if (child.pid) {
+      try { process.kill(-child.pid, 'SIGTERM'); } catch (error) {
+        if (error.code !== 'ESRCH') throw error;
+      }
+      await sleep(500);
+      try { process.kill(-child.pid, 'SIGKILL'); } catch (error) {
+        if (error.code !== 'ESRCH') throw error;
+      }
+    }
+    fs.rmSync(runDir, {recursive: true, force: true});
+  }
+})();