ci.yml

## This GitHub workflow is inspired by a workflow from the Oracle Docker Images repository,
## which is licensed under the Universal Permissive License (UPL) version 1.0.
##
## Copyright (c) 2019, 2023 Oracle and/or its affiliates.
## The Universal Permissive License (UPL), Version 1.0, https://oss.oracle.com/licenses/upl/
##
## https://github.com/oracle/docker-images/blob/73fc5e48f3efffd311a8ca5cc74c4b094855e02e/.github/workflows/build-and-push-dev-images.yml

name: CI

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main
  merge_group:

jobs:
  prepare:
    runs-on: ubuntu-22.04

    outputs:
      skip_build: ${{ steps.changes.outputs.skip_build }}
      matrix: ${{ steps.changes.outputs.matrix }}

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Create matrix for changed images
        id: changes
        run: |
          changes=$(mktemp)
          latest_tag=$(git describe --tags --abbrev=0)
          git diff --name-only --patch "${latest_tag}..HEAD" > "${changes}"
          matrix=$(
            for dockerfile in */Dockerfile; do
              image=$(dirname "${dockerfile}")
              version=$(grep -m1 'FROM ' "${dockerfile}" | awk -F ':' '{print $2}' | sed 's/[^0-9.]//g')
              if [ -n "$version" ] && grep -q "${image}" "${changes}"; then
                echo "${image};${version}"
              fi
            done | jq --slurp --raw-input --compact-output '
              split("\n") |
              .[:-1] |
              map(split(";")) |
              map({"image": .[0], "version": .[1]})'
          )
          rm "${changes}"
          if [[ ${matrix} == "[]" ]]; then
            # Empty array -- change didn't impact any image
            skip_build=true
          else
            skip_build=false
            matrix=$(jq --compact-output '{ "include": .}' <<<"${matrix}")
          fi
          echo "skip_build=${skip_build}" >> "$GITHUB_OUTPUT"
          echo "matrix=${matrix}" >> "$GITHUB_OUTPUT"

  build:
    needs: [ prepare ]

    if: always() && needs.prepare.outputs.skip_build == 'false'

    strategy:
      matrix: ${{fromJson(needs.prepare.outputs.matrix)}}
      fail-fast: false

    runs-on: ubuntu-22.04

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to GHCR
        uses: docker/#-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build image
        uses: docker/build-push-action@v6
        with:
          context: ${{ matrix.image }}
          load: true
          tags: "ghcr.io/${{ github.repository_owner }}/${{ matrix.image }}:${{ matrix.version }}"

      - name: Push image
        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
        run: |
          docker push "ghcr.io/${{ github.repository_owner }}/${{ matrix.image }}:${{ matrix.version }}"

      - name: Tag commit
        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
        run: |
          git tag "${{ matrix.image }}-${{ matrix.version }}"
          git push origin "${{ matrix.image }}-${{ matrix.version }}"

      - name: Inspect image
        run: |
          docker image inspect ghcr.io/${{ github.repository_owner }}/${{ matrix.image }}:${{ matrix.version }}

  ## This job is used to aggregate the result of the 'build' matrix job.
  ## There doesn't seem to be another way to have status checks based on "dynamic" matrix jobs.
  build_success:
    needs: [ build ]
    runs-on: ubuntu-22.04
    steps:
      - name: Build success
        run: echo "Build success"