docker-publish.yml

name: Docker

# This workflow uses actions that are not certified by GitHub.
# They are provided by a third-party and are governed by separate
# terms of service, privacy policy, and support documentation.
# Based on: https://github.com/actions/starter-workflows/blob/main/ci/docker-publish.yml

on:
  schedule:
    - cron: 30 11 * * *
    # min hr * * * (UTC)
  push:
    branches:
      - master
    tags: '*'

env:
  # Use docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
      # This is used to complete the identity challenge with sigstore/fulcio
      id-token: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      # Install the cosign tool
      # https://github.com/sigstore/cosign-installer
      - name: Install Cosign
        uses: sigstore/cosign-installer@v3

      # Set up Docker Buildx
      # https://github.com/docker/setup-buildx-action
      - name: Setup Docker buildx
        uses: docker/setup-buildx-action@v3

      # Login against a Docker registry
      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract metadata (tags, labels) for Docker
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # Build and push Docker image with Buildx
      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      # Sign the resulting Docker image digest
      # This will only write to the public Rekor transparency log when the Docker
      # repository is public to avoid leaking data. To publish transparency data,
      # even for private images, pass --force to cosign below.
      # https://github.com/sigstore/cosign
      - name: Sign the published Docker image
        env:
          tags: ${{ steps.meta.outputs.tags }}
          digest: ${{ steps.build-and-push.outputs.digest }}
        # This step uses the identity token to provision an ephemeral certificate
        # against the sigstore community Fulcio instance.
        run: echo "${tags}" | xargs -I {} cosign sign --yes {}@${digest}