GitHub packages build and push image pipeline.

docker.yaml

# Create a directory path .github/workflows/
# put the docker.yaml in the workflows directory
# once the build is working, change `on:` to build on tags
# on:
#  create:
#    tags:
#      - v*
# this will make sure the build will only trigger when a new git tag is created

name: Build and Publish Docker Image

on:
  push:
    branches: [ master ]
  pull_request:
    branches: [ master ]
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build-and-push-image:
      runs-on: ubuntu-latest
      permissions:
        contents: read
        packages: write

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

        - name: Set up JDK
          uses: actions/setup-java@v1
          with:
            java-version: 1.11
          
        - name: Build with Maven
          run: mvn clean install
      
        - name: Log in to the Container registry
          uses: docker/login-action@v2
          with:
            registry: ${{ env.REGISTRY }}
            username: ${{ github.actor }}
            password: ${{ secrets.GITHUB_TOKEN }}

        - name: Extract metadata (tags, labels) for Docker
          id: meta
          uses: docker/metadata-action@v4
          with:
            images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

        - name: Build and push Docker image
          uses: docker/build-push-action@v3
          with:
            context: .
            push: true
            tags: ${{ steps.meta.outputs.tags }}
            labels: ${{ steps.meta.outputs.labels }}

FROM openjdk:11

EXPOSE 8080

WORKDIR /applications

COPY target/sample-application-0.0.1-SNAPSHOT.jar /applications/sample-application.jar

ENTRYPOINT ["java","-jar", "sample-application.jar"]