Draupnir/.github/workflows/validate-docker-build.yml

# SPDX-FileCopyrightText: 2026 Catalan Lover <catalanlover@protonmail.com>
#
# SPDX-License-Identifier: Apache-2.0
# This file is derived from the ghcr-all-dev-branches.yml workflow, but instead of pushing its results, it only validates the Docker build. It also runs on all excluded branches to validate builds on excluded branches.

name: "Validate Docker Build"

# Main is not excluded due to that we want access to validate the build on main and to enable scout mode just like we have for breaking synapse changes.
on:
  push:
    branches-ignore:
      - "dependabot/**"
      - "github-actions/**"
      - "gh-readonly-queue/**"
  schedule:
    - cron: "20 20 * * *"
  pull_request:
    branches-ignore:
      - "dependabot/**"
      - "github-actions/**"
  merge_group:
    branches: [main]

env:
  IMAGE_NAME: draupnir
  PLATFORMS: linux/amd64,linux/arm64
  IMG_SOURCE: https://github.com/${{ github.repository }}

jobs:
  validate-docker-build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - name: Check out
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
        with:
          fetch-depth: 0
          fetch-tags: true
      - name: Set lowercase image owner
        id: image_owner
        run:
          echo "image_owner=$(echo '${{ github.repository_owner }}' | tr
          '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT

      # Needed for multi platform builds
      - name: Set up QEMU
        uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a
        with:
          platforms: ${{ env.PLATFORMS }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd

      - name: Derive image tags
        id: meta
        uses: docker/metadata-action@030e881283bb7a6894de51c315a6bfe6a94e05cf
        with:
          images:
            ghcr.io/${{ steps.image_owner.outputs.image_owner }}/${{
            env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=sha,prefix=sha-

      - name: Build image
        id: push
        uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f
        with:
          context: .
          file: ./Dockerfile
          platforms: ${{ env.PLATFORMS }}
          push: false
          # Shared Buildx cache scope reused by all container image workflows.
          # Keep the scope name aligned across workflows to maximize cache hits.
          cache-from: type=gha,scope=draupnir-container-build
          labels: |
            org.opencontainers.image.source=${{ env.IMG_SOURCE }}
            org.opencontainers.image.revision=${{ github.sha }}
            org.opencontainers.image.version=${{ github.ref_name }}-${{ github.sha }}
            org.opencontainers.image.ref.name=${{ github.ref_name }}
            org.opencontainers.image.licenses=Apache-2.0

          # prettier-ignore
          outputs: type=image,name=target,annotation-index.org.opencontainers.image.description=Draupnir is a community management platform for Matrix.
          sbom: true
          provenance: true
          tags: ${{ steps.meta.outputs.tags }}