build-publish-app-container.yaml

name: Build & Publish Image

on:
  push:
    branches:
      - main

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@v4
      # 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@5139682d94efc37792e6b54386b5b470a68a4737
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # 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@232fc64e3a4e54539e087c5976439ea54be0959d
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
      # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
      # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see "[Usage](https://github.com/docker/build-push-action#usage)" in the README of the `docker/build-push-action` repository.
      # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
      - name: Build and push Docker image
        uses: docker/build-push-action@af5a7ed5ba88268d5278f7203fb52cd833f66d6e
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          file: Dockerfile