Test build on pull requests (#102)

* Build image on pull-requests and publish on main and tags

* Only on pull-requests to main

* Use artifact to save/load container from build to publish job

* Add missing variable

* Add missing needed step

* Cleanup useless step ids

Author: leplatrem

.github/workflows/build-image.yaml renamed to .github/workflows/build-publish.yaml

@@ -1,6 +1,10 @@
-name: Build Docker image
+name: Build and Publish Docker image
 
 on:
+  pull_request:
+    branches:
+    - main
+
   push:
     branches:
     - main
@@ -27,17 +31,14 @@ jobs:
           fi
         env:
           version_pattern: "tags\\/v[0-9]+\\.[0-9]+\\.[0-9]+"
-  build-image:
+  build:
     runs-on: ubuntu-latest
     needs: prepare
     environment:
         name: cloudops
-    outputs:
-      BUILD_TAG: ${{ steps.build-push.outputs.build-tag }}
 
     steps:
-      - name: Echo tag
-        id: echotag
+      - name: Docker image tag
         env:
           IMAGE_TAG: ${{ needs.prepare.outputs.FULL_IMAGE_TAG }}
         run: |
@@ -54,14 +55,11 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Extract metadata (tags, labels) for Docker
-        id: meta
         uses: docker/metadata-action@v3
         with:
           images: $GITHUB_REPOSITORY
 
-
-      - name: Build and push to Docker Hub
-        id: build-push
+      - name: Build Docker image
         env:
           IMAGE_TAG: ${{ needs.prepare.outputs.FULL_IMAGE_TAG }}
         run: |
@@ -72,8 +70,46 @@ jobs:
             "$GITHUB_SERVER_URL/$GITHUB_REPOSITORY" \
             "$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID" > ./version.json
           docker build --file Dockerfile -t $GITHUB_REPOSITORY:$IMAGE_TAG .
+
+      - name: Save image as artifact
+        env:
+          IMAGE_TAG: ${{ needs.prepare.outputs.FULL_IMAGE_TAG }}
+        run: |
+          docker save -o /tmp/container.tar.gz $GITHUB_REPOSITORY:$IMAGE_TAG
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: container-image
+          path: /tmp/container.tar.gz
+          retention-days: 1  # Instead of default 90 days
+
+  publish:
+    runs-on: ubuntu-latest
+    needs:
+      - prepare
+      - build
+    if: ${{ !github.event.pull_request }} # Exclude pull-requests (see `on:` above)
+
+    steps:
+      - uses: actions/download-artifact@v3
+        with:
+          name: container-image
+          path: /tmp/container.tar.gz
+
+      - name: Load container from artifact
+        run: |
+          docker load -i /tmp/container.tar.gz
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build Docker image
+        env:
+          IMAGE_TAG: ${{ needs.prepare.outputs.FULL_IMAGE_TAG }}
+        run: |
           docker image tag $GITHUB_REPOSITORY:$IMAGE_TAG $GITHUB_REPOSITORY:latest
           docker push $GITHUB_REPOSITORY:$IMAGE_TAG
           docker push $GITHUB_REPOSITORY:latest
-          echo "::set-output name=build-tag::$IMAGE_TAG"
-          echo "::debug::Set the build-tag output as $IMAGE_TAG"