name: "Test build of image when Dockerfile is changed"

on:
  push:
    paths:
    - 'Dockerfile'
    branches-ignore:
    - main
  pull_request:
    paths:
    - 'Dockerfile'
  workflow_dispatch:

# Least-privilege default token (this workflow only reads the repo and pulls cache)
permissions:
  contents: read

# Cancel superseded runs for the same ref to save CI minutes
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

env:
  GHCR_REPO: ghcr.io/${{ github.repository_owner }}/p2pool

jobs:
  rebuild-container:
    name: "Build image with cache"
    timeout-minutes: 60
    permissions:
      contents: read
      packages: read
    strategy:
      fail-fast: false
      matrix:
        os:
          - ubuntu-latest
          - ubuntu-24.04-arm
    runs-on: ${{ matrix.os }}
    steps:
      - name: Prepare platform matrix for arm64
        if: runner.arch == 'ARM64'
        run: |
          echo "PLATFORM=linux/arm64" >> $GITHUB_ENV
          echo "DIGEST_NAME=arm64" >> $GITHUB_ENV
      - name: Prepare platform matrix for amd64
        if: runner.arch == 'X64'
        run: |
          echo "PLATFORM=linux/amd64" >> $GITHUB_ENV
          echo "DIGEST_NAME=amd64" >> $GITHUB_ENV
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v4.1.0
      - name: Checkout repository
        uses: actions/checkout@v7
        with:
          persist-credentials: false
      - name: Test build of image
        id: build
        uses: docker/build-push-action@v7.2.0
        with:
          push: false
          load: true
          platforms: ${{ env.PLATFORM }}
          tags: p2pool:testing
          cache-from: |
            type=registry,ref=${{ env.GHCR_REPO }}:buildcache-${{ env.DIGEST_NAME }}
            type=registry,ref=${{ env.GHCR_REPO }}:latest
      - name: Verify reported version matches the pinned p2pool tag
        run: |
          set -euo pipefail
          EXPECTED="$(awk -F= '/^ARG P2POOL_BRANCH=/{print $2; exit}' Dockerfile)"
          echo "Expecting p2pool to report: ${EXPECTED}"
          OUT="$(docker run --rm p2pool:testing --help 2>&1 || true)"
          echo "${OUT}" | head -1
          echo "${OUT}" | grep -q "${EXPECTED}" \
            || { echo "::error::p2pool banner does not contain expected tag ${EXPECTED}"; exit 1; }
      - name: Verify the container starts and stays up
        run: |
          set -uo pipefail
          CID="$(docker run -d p2pool:testing --wallet 468ydghFfthE3UTc53eF5MP9UyrMcUiAHP5kizVYJsej5XGaXBoAAEzUHCcUF7t3E3RrYAX8Rs1ujhBdcvMpZSbH8qkb55R)"
          sleep 20
          if [ "$(docker inspect -f '{{.State.Running}}' "$CID" 2>/dev/null || echo false)" != "true" ]; then
            echo "::error::container exited early"; docker logs "$CID" 2>&1 || true
            docker rm -f "$CID" >/dev/null 2>&1 || true; exit 1
          fi
          docker rm -f "$CID" >/dev/null 2>&1 || true