only push image after tests pass

Author: tim-br

.github/workflows/build_and_push.yaml

@@ -10,6 +10,9 @@ on:
       - main
   workflow_dispatch:
 
+env:
+  REGISTRY: ghcr.io
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -66,3 +69,90 @@ jobs:
 
       - name: Run tests (including property tests)
         run: mix test --include test
+
+  docker-build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ github.repository_owner }}/cascade
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=sha,prefix={{branch}}-
+            type=raw,value=latest,enable={{is_default_branch}}
+
+      - name: Build Docker image (no push)
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: false
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+          outputs: type=docker,dest=/tmp/cascade-image.tar
+
+      - name: Upload Docker image artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: cascade-docker-image
+          path: /tmp/cascade-image.tar
+          retention-days: 1
+
+  docker-push:
+    runs-on: ubuntu-latest
+    needs: [test, docker-build]
+    if: github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/develop')
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Download Docker image artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: cascade-docker-image
+          path: /tmp
+
+      - name: Load Docker image
+        run: docker load --input /tmp/cascade-image.tar
+
+      - name: Log in to Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ github.repository_owner }}/cascade
+          tags: |
+            type=ref,event=branch
+            type=sha,prefix={{branch}}-
+            type=raw,value=latest,enable={{is_default_branch}}
+
+      - name: Push Docker image to registry
+        run: |
+          for tag in $(echo "${{ steps.meta.outputs.tags }}" | tr ',' ' '); do
+            docker tag $(docker images -q | head -n1) $tag
+            docker push $tag
+          done