PPHA-369: Add docker build steps to build pipeline

Author: Themitchell

.github/workflows/stage-3-build.yaml

@@ -32,38 +32,56 @@ on:
         required: true
         type: string
 
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+  DOCKER_METADATA_PR_HEAD_SHA: true
+
 jobs:
-  artefact-1:
-    name: "Artefact 1"
-    runs-on: ubuntu-latest
-    timeout-minutes: 3
-    steps:
-      - name: "Checkout code"
-        uses: actions/checkout@v5
-      - name: "Build artefact 1"
-        run: |
-          echo "Building artefact 1 ..."
-      - name: "Check artefact 1"
-        run: |
-          echo "Checking artefact 1 ..."
-      - name: "Upload artefact 1"
-        run: |
-          echo "Uploading artefact 1 ..."
-          # TODO: Use either action/cache or action/upload-artifact
-  artefact-2:
-    name: "Artefact 2"
+  build:
+    name: 'Build'
     runs-on: ubuntu-latest
     timeout-minutes: 3
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+
     steps:
-      - name: "Checkout code"
+      - name: 'Checkout code'
         uses: actions/checkout@v5
-      - name: "Build artefact 2"
-        run: |
-          echo "Building artefact 2 ..."
-      - name: "Check artefact 2"
-        run: |
-          echo "Checking artefact 2 ..."
-      - name: "Upload artefact 2"
-        run: |
-          echo "Uploading artefact 2 ..."
-          # TODO: Use either action/cache or action/upload-artifact
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=ref,event=tag
+            type=raw,value=${{ github.event_name == 'pull_request' && github.event.pull_request.head.ref || '{{branch}}' }}
+            type=raw,value=${{ github.event_name == 'pull_request' && format('pr-{0}', github.event.pull_request.number) || '' }}
+            type=sha,format=long,prefix=git-sha-
+
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+      - name: Generate artifact attestation
+        uses: actions/attest-build-provenance@v3
+        with:
+          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
+          subject-digest: ${{ steps.push.outputs.digest }}
+          push-to-registry: true