docker-publish.yml

name: Push to GHCR

on:
  # schedule:
    # - cron: '19 22 * * *'
  push:
    branches: [ "main" ]
  pull_request:
    branches: [ "main" ]

env:
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:
  
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      id-token: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v3

      - name: Install cosign
        if: github.event_name != 'pull_request'
        uses: sigstore/cosign-installer@6e04d228eb30da1757ee4e1dd75a0ec73a653e06 #v3.1.1
        with:
          cosign-release: 'v2.1.1'

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@f95db51fddba0c2d1ec667646a06c2ce06100226 # v3.0.0

      - name: Log into registry ${{ env.REGISTRY }}
        if: github.event_name != 'pull_request'
        uses: docker/login-action@343f7c4344506bcbf9b4de18042ae17996df046d # v3.0.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@96383f45573cb7f253c731d3b3ab81c87ef81934 # v5.0.0
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@0565240e2d4ab88bba5387d719585280857ece09 # v5.0.0
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Sign the published Docker image
        if: ${{ github.event_name != 'pull_request' }}
        env:
          # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
          TAGS: ${{ steps.meta.outputs.tags }}
          DIGEST: ${{ steps.build-and-push.outputs.digest }}
          
        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}