name: Mirror Node Base Image (Docker Hub to GHCR)

# Keeps a copy of the official node images our Dockerfiles build FROM in GHCR.
# Anonymous pulls from Docker Hub / ECR Public are rate limited per source IP,
# and GitHub-hosted runners share IPs, so CI builds were failing with 429s.
# Public GHCR packages pull without credentials, so PR builds (including from
# forks) need no secrets.
#
# The tags to mirror are read from the Dockerfiles themselves: any reference to
# ghcr.io/<owner>/node:<tag> is copied from docker.io/library/node:<tag>. Bumping
# the Node version in a Dockerfile and pushing it mirrors the new tag
# automatically. The daily run picks up upstream rebuilds (OS security patches)
# of the same tag.
#
# NOTE: the first push creates the ghcr.io/<owner>/node package as private.
# Make it public once in the org's package settings so builds can pull it
# anonymously.

permissions:
  contents: read
  packages: write

on:
  schedule:
    - cron: "17 4 * * *"
  push:
    paths:
      - "Dockerfile*"
      - ".github/workflows/mirror-node.yml"
  workflow_dispatch:
    inputs:
      tags:
        description: "Extra node tags to mirror, space separated (e.g. 24.23.0-slim)"
        required: false
        default: ""

concurrency:
  group: mirror-node
  cancel-in-progress: false

env:
  SOURCE_IMAGE: docker.io/library/node
  DEST_IMAGE: ghcr.io/${{ github.repository_owner }}/node

jobs:
  mirror:
    # Don't run (and push to their own GHCR) in forks
    if: github.repository_owner == 'fosrl'
    runs-on: ubuntu-latest
    timeout-minutes: 30
    steps:
      - name: Checkout repository
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

      - name: Install skopeo
        run: |
          sudo apt-get update -y
          sudo apt-get install -y skopeo
          skopeo --version

      - name: Log in to registries
        env:
          GHCR_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          DOCKER_HUB_USERNAME: ${{ secrets.DOCKER_HUB_USERNAME }}
          DOCKER_HUB_ACCESS_TOKEN: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
        run: |
          set -euo pipefail
          # runner.temp isn't available in job-level env, so export it here
          # for this and later steps.
          export REGISTRY_AUTH_FILE="${RUNNER_TEMP}/containers/auth.json"
          echo "REGISTRY_AUTH_FILE=${REGISTRY_AUTH_FILE}" >> "$GITHUB_ENV"
          mkdir -p "$(dirname "$REGISTRY_AUTH_FILE")"
          echo "$GHCR_TOKEN" | skopeo login ghcr.io -u "${{ github.actor }}" --password-stdin
          # Authenticated Docker Hub pulls avoid the shared-IP anonymous limit.
          # This only runs on trusted refs (schedule/push/dispatch), never PRs.
          if [ -n "$DOCKER_HUB_USERNAME" ] && [ -n "$DOCKER_HUB_ACCESS_TOKEN" ]; then
            echo "$DOCKER_HUB_ACCESS_TOKEN" | skopeo login docker.io -u "$DOCKER_HUB_USERNAME" --password-stdin
          fi

      - name: Collect tags
        env:
          EXTRA_TAGS: ${{ inputs.tags }}
        run: |
          set -euo pipefail
          {
            grep -hoE "${DEST_IMAGE}:[A-Za-z0-9._-]+" Dockerfile* | sed "s|^${DEST_IMAGE}:||" || true
            for t in ${EXTRA_TAGS:-}; do echo "$t"; done
          } | sort -u > tags.txt
          if [ ! -s tags.txt ]; then
            echo "::error ::No ${DEST_IMAGE}:<tag> references found in Dockerfiles"
            exit 1
          fi
          echo "Tags to mirror:"
          cat tags.txt

      - name: Mirror tags
        run: |
          set -euo pipefail
          errs=0
          while read -r tag; do
            if ! [[ "$tag" =~ ^[A-Za-z0-9._-]+$ ]]; then
              echo "::warning ::Skipping invalid tag '${tag}'"
              errs=$((errs+1)); continue
            fi

            src="${SOURCE_IMAGE}:${tag}"
            dst="${DEST_IMAGE}:${tag}"

            if ! skopeo inspect --raw --retry-times 3 "docker://${src}" > src.json; then
              echo "::warning title=Inspect failed::${src}"
              errs=$((errs+1)); continue
            fi
            src_digest="$(skopeo manifest-digest src.json)"

            dst_digest=""
            if skopeo inspect --raw --retry-times 3 "docker://${dst}" > dst.json 2>/dev/null; then
              dst_digest="$(skopeo manifest-digest dst.json)"
            fi

            if [ "$src_digest" = "$dst_digest" ]; then
              echo "Up to date: ${dst} (${src_digest})"
              continue
            fi

            echo "==> Copy ${src} (${src_digest}) -> ${dst}"
            # --all keeps every architecture; --preserve-digests keeps the
            # mirror byte-identical so it can be pinned by the upstream digest.
            if ! skopeo copy --all --preserve-digests --retry-times 3 \
                 "docker://${src}" "docker://${dst}"; then
              echo "::warning title=Copy failed::${src}"
              errs=$((errs+1))
            fi
          done < tags.txt

          if [ "$errs" -gt 0 ]; then
            echo "::error ::${errs} tag(s) failed to mirror"
            exit 1
          fi