update the docker workflow to build a devcontainer specifically

Signed-off-by: Justin Pflueger <[email protected]>

.github/workflows/docker.yaml

@@ -2,37 +2,80 @@ name: docker
 
 on:
   push:
-    branches: [ main ]
+    branches: ["main"]
+    tags: ["v*.*.*"]
+    paths:
+      - .devcontainer/Dockerfile
+      - .github/workflows/docker.yaml
+  pull_request:
+    branches: ["main"]
     paths:
       - .devcontainer/Dockerfile
       - .github/workflows/docker.yaml
   workflow_dispatch:
+
 jobs:
   docker:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      id-token: write
     steps:
       - name: Checkout
         uses: actions/checkout@v3
 
-      - name: Setup version info
-        run: echo "VERSION=$(date +%Y%m%d-%H%M%S)-g$(git rev-parse --short HEAD)" >> $GITHUB_ENV
+      # Install the cosign tool except on PR
+      # https://github.com/sigstore/cosign-installer
+      - name: Install cosign
+        if: github.event_name != 'pull_request'
+        uses: sigstore/[email protected]
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
+        uses: docker/setup-buildx-action@v3
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@v2
+        uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build
-        uses: docker/build-push-action@v4
+      # Extract metadata (tags, labels) for Docker
+      # https://github.com/docker/metadata-action
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@96383f45573cb7f253c731d3b3ab81c87ef81934 # v5.0.0
         with:
-          push: true
-          context: ./.devcontainer
-          platforms: linux/amd64, linux/arm64
+          images: |
+            ghcr.io/${{ github.repository }}
           tags: |
-            ghcr.io/fermyon/workshops/dev-container:${{ env.VERSION }}
+            type=semver,pattern={{version}}
+            type=ref,event=pr
+            type=sha,enable={{is_default_branch}},prefix={{date 'YYYYMMDD-HHmmss'}}-,suffix=,format=short
+
+      # Build the Docker image with Buildx (don't push yet)
+      # https://github.com/docker/build-push-action
+      - name: Build Docker image
+        id: build-and-push
+        uses: docker/build-push-action@v5
+        with:
+          context: .devcontainer
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
 
+      # Uses the cached prebuilt image and adds
+      # devcontainer features and metadata before pushing
+      - name: Add devcontainer extras and push
+        uses: devcontainers/[email protected]
+        with:
+          cacheFrom: ghcr.io/${{ github.repository }}
+          imageName: ghcr.io/${{ github.repository }}
+          imageTag: ${{ join(steps.meta.outputs.tags) }}
+          skipContainerUserIdUpdate: true
+          platform: linux/amd64,linux/arm64