ci: Create build-docker-image.yml

Merge pull request #4 from DFE-Digital/add-docker-build-and-publish

.github/workflows/build-docker-image.yml

@@ -0,0 +1,102 @@
+name: Docker Publish
+
+# 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.
+
+on:
+  release:
+    types: [published]
+
+env:
+  # Use docker.io for Docker Hub if empty
+  REGISTRY: ghcr.io
+  # github.repository as <account>/<repo>
+  IMAGE_NAME: ${{ github.repository }}
+  RELEASE_TAG: ${{ github.event.release.tag_name }}
+
+jobs:
+  build:
+    name: 'Docker Publish'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      # This is used to complete the identity challenge
+      # with sigstore/fulcio when running outside of PRs.
+      id-token: write
+
+    steps:
+      # Checkout the release tag version
+      - name: Checkout repository ${{ env.RELEASE_TAG }}
+        uses: actions/checkout@v3
+        with:
+          ref: ${{ env.RELEASE_TAG }}
+
+      # Get git commit hash
+      - name: Get short hash
+        run: echo "sha_short=$(git rev-parse --short HEAD)" >> $GITHUB_ENV
+
+      # Need to lower case the image name for the docker tags when publishing
+      - name: Downcase IMAGE_NAME variable
+        run:  echo "IMAGE_NAME_LOWER=${IMAGE_NAME,,}" >> $GITHUB_ENV
+
+      # Sort out the image tags 
+      - name: Set initial tag
+        run: echo "IMAGE_TAGS=${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LOWER }}:${{ env.RELEASE_TAG }}" >> $GITHUB_ENV
+
+      - name: Add latest tag if we're not production release
+        if: contains(env.RELEASE_TAG, 'next')
+        run: echo "IMAGE_TAGS=${{ env.IMAGE_TAGS }},${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LOWER }}:latest" >> $GITHUB_ENV
+
+      #debug
+      - name: Log the tags
+        run: echo "Calculated tags value => ${{ env.IMAGE_TAGS }}"
+
+      # Setup docker build tool
+      - name: Setup Docker buildx
+        uses: docker/setup-buildx-action@v3
+
+      # Login against a Docker registry
+      - 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
+      - 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 (don't push on PR)
+      - name: Build and push Docker image
+        id: build-and-push
+        uses: docker/build-push-action@v5
+        with:
+          context: ./src/Childrens-Social-Care-CPD-Indexer
+          #push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ env.IMAGE_TAGS }}
+          labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            VCSREF=${{ env.sha_short }}
+            VCSTAG=${{ env.RELEASE_TAG }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      # Sign the resulting Docker image digest.
+      # This will only write to the public Rekor transparency log when the Docker
+      # repository is public to avoid leaking data.  If you would like to publish
+      # transparency data even for private images, pass --force to cosign below.
+      # https://github.com/sigstore/cosign
+      - name: Install Cosign
+        uses: sigstore/[email protected]
+      - name: Check install!
+        run: cosign version
+      - name: Sign the published Docker image
+        # This step uses the identity token to provision an ephemeral certificate against the sigstore community Fulcio instance.
+        run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign {}@${{ steps.build-and-push.outputs.digest }}