ci: add matrix + tags

.github/workflows/build-deploy.yml

@@ -6,8 +6,22 @@ on:
 jobs:
   build_deploy:
     runs-on: 'ubuntu-22.04'
+    strategy:
+      matrix:
+        image:
+          [
+            { dockerfile: 'Dockerfile.pnpm', target: 'prep' },
+            { dockerfile: 'Dockerfile.pnpm', target: 'home' },
+            { dockerfile: 'Dockerfile.postgres', tag: 'postgres' }
+          ]
     # See: https://github.com/docker/build-push-action
     steps:
+      - name: Generate Docker tags
+        uses: docker/metadata-action@v5
+        with:
+          images: 'hackbu/${{ matrix.image.target || matrix.image.tag }}'
+          tags: type=sha
+          flavor: latest=true
       # Docs: https://github.com/docker/setup-qemu-action
       - name: 'Setup QEMU to emulate other platforms'
         uses: 'docker/setup-qemu-action@v3'
@@ -21,7 +35,10 @@ jobs:
       - name: 'Build and push'
         uses: 'docker/build-push-action@v5'
         with:
-          file: './docker/Dockerfile.pnpm'
+          file: './docker/${{ matrix.image.dockerfile }}'
+          target: '${{ matrix.image.target }}'
           platforms: 'linux/amd64,linux/arm64'
           # TODO
-          push: 'false'
+          push: false
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.tags }}