maven-package-push.yml

name: Build and Package with Maven

# Defines two custom environment variables for the workflow. These are used for the Container registry domain, and a name for the Docker image that this workflow builds.
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

on:
  push:
    branches:
      - main

jobs:
  build:
    name: Build and Package Application
    runs-on: ubuntu-latest
    # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
    permissions:
      contents: read
      packages: write
      attestations: write
      id-token: write
    steps:
      # Step 1: Checkout the repository
      - name: Checkout Code
        uses: actions/checkout@v3

      # Step 2: Set up JDK for Maven
      - name: Set up JDK 17
        uses: actions/setup-java@v3
        with:
          java-version: '17'
          distribution: 'temurin'

      # Step 3: Cache Maven dependencies
      - name: Cache Maven Dependencies
        uses: actions/cache@v3
        with:
          path: ~/.m2/repository
          key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
          restore-keys: |
            ${{ runner.os }}-maven-
            
      # Step 6: This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about) to extract tags and labels that will be applied to the specified image. The `id` "meta" allows the output of this step to be referenced in a subsequent step. The `images` value provides the base name for the tags and labels.
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # Step 4: Build docker image
      - name: Build Application with Maven
        run: mvn clean test spring-boot:build-image -Dspring-boot.build-image.imageName=notesapp:${{ steps.meta.outputs.tags }}

      # Step 5: Uses the `docker/login-action` action to log in to the Container registry registry using the account and password that will publish the packages. Once published, the packages are scoped to the account defined here.
      - name: Log in to the Container registry
        uses: docker/login-action@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
        
      # Step 8: Push to Container Registry
      - name: Push image to Container Registry
        id: push
        run: docker push notesapp:${{ steps.meta.outputs.tags }}
        
      # Step 9: This step generates an artifact attestation for the image, which is an unforgeable statement about where and how it was built. It increases supply chain security for people who consume the image. For more information, see "[AUTOTITLE](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds)." 
      - name: Generate artifact attestation
        uses: actions/attest-build-provenance@v1
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
          subject-digest: ${{ steps.push.outputs.digest }}
          push-to-registry: true