docker-publish.yml

name: Publish image (main)

# Rolling dev image for the main branch (:main and :sha-<commit>), for self-hosters
# tracking the tip. Versioned tags (:X.Y.Z, :X.Y, :latest) and npm are owned by
# release.yml — this workflow deliberately does not trigger on tags.
on:
  push:
    branches: [main]
  workflow_dispatch:

concurrency:
  group: docker-main-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    if: github.repository == 'lukaisailovic/openislands'
    permissions:
      contents: read
      packages: write
      attestations: write
      id-token: write
    steps:
      - uses: actions/checkout@v4
        with:
          persist-credentials: false

      - uses: ./.github/actions/ghcr-buildx

      - name: Extract image metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          # :main on a branch push, :sha-<commit> on every run.
          tags: |
            type=ref,event=branch
            type=sha

      - name: Build and push
        id: push
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: linux/amd64
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      # Attestation lands in GitHub's native store (verify with `gh attestation
      # verify oci://...`). Not pushed to the registry — that fallback creates a
      # `sha256-<digest>` referrer tag that clutters the tag list.
      - name: Attest build provenance
        uses: actions/attest-build-provenance@v2
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          subject-digest: ${{ steps.push.outputs.digest }}