Ensure Docker images built from PRs are stored as artifacts. This allows us to use those new images when testing deployment (in docker-deploy)

.github/workflows/docker.yml

@@ -157,15 +157,35 @@ jobs:
     if: github.repository == 'dspace/dspace'
     runs-on: ubuntu-latest
     # Must run after all major images are built
-    needs: [dspace-test, dspace-cli, dspace-postgres-pgcrypto, dspace-solr]
+    needs: [dspace, dspace-test, dspace-cli, dspace-postgres-pgcrypto, dspace-solr]
     steps:
+      # Checkout our codebase (to get access to Docker Compose scripts)
       - name: Checkout codebase
         uses: actions/checkout@v4
+      # For PRs, download Docker image artifacts (built by reusable-docker-build.yml for all PRs)
+      - name: Download Docker image artifacts (for PRs)
+        if: github.event_name == 'pull_request'
+        uses: actions/download-artifact@v4
+        with:
+          # Download all Docker images (TAR files) into the /tmp/docker directory
+          pattern: docker-image-*
+          path: /tmp/docker
+          merge-multiple: true
+      # For PRs, load each of the images into Docker by calling "docker image load" for each.
+      # This ensures we are using the images built from this PR & not the prior versions on DockerHub
+      - name: Load all downloaded Docker images (for PRs)
+        if: github.event_name == 'pull_request'
+        run: |
+          find /tmp/docker -type f -name "*.tar" -exec docker image load --input "{}" \;
+          docker image ls -a
       # Start backend using our compose script in the codebase.
       - name: Start backend in Docker
         env:
           # Override defaults dspace.server.url because backend starts at http://127.0.0.1:8080
           dspace__P__server__P__url: http://127.0.0.1:8080/server
+          # Force using "pr-testing" version of Docker images. The "pr-testing" tag is a temporary tag that we assign to
+          # all PR-built docker images in reusabe-docker-build.yml
+          DSPACE_VER: pr-testing
         run: |
           docker compose -f docker-compose.yml up -d
           sleep 10

.github/workflows/reusable-docker-build.yml

@@ -113,6 +113,12 @@ jobs:
       - name: Set up QEMU emulation to build for multiple architectures
         uses: docker/setup-qemu-action@v3
 
+      #------------------------------------------------------------
+      # Build & deploy steps for new commits to a branch (non-PRs)
+      #
+      # These steps build the images, push to DockerHub, and
+      # (if necessary) redeploy demo/sandbox sites.
+      #------------------------------------------------------------
       # https://github.com/docker/login-action
       - name: Login to DockerHub
         # Only login if not a PR, as PRs only trigger a Docker build and not a push
@@ -125,6 +131,7 @@ jobs:
       # https://github.com/docker/metadata-action
       # Get Metadata for docker_build_deps step below
       - name: Sync metadata (tags, labels) from GitHub to Docker for image
+        if: ${{ ! matrix.isPr }}
         id: meta_build
         uses: docker/metadata-action@v5
         with:
@@ -133,7 +140,9 @@ jobs:
           flavor: ${{ env.TAGS_FLAVOR }}
 
       # https://github.com/docker/build-push-action
-      - name: Build and push image
+      - name: Build and push image to DockerHub
+        # Only build & push if not a PR
+        if: ${{ ! matrix.isPr }}
         id: docker_build
         uses: docker/build-push-action@v5
         with:
@@ -142,9 +151,7 @@ jobs:
           context: ${{ inputs.dockerfile_context }}
           file: ${{ inputs.dockerfile_path }}
           platforms: ${{ matrix.arch }}
-          # For pull requests, we run the Docker build (to ensure no PR changes break the build),
+          push: true
-          # but we ONLY do an image push to DockerHub if it's NOT a PR
-          push: ${{ ! matrix.isPr }}
           # Use tags / labels provided by 'docker/metadata-action' above
           tags: ${{ steps.meta_build.outputs.tags }}
           labels: ${{ steps.meta_build.outputs.labels }}
@@ -189,11 +196,54 @@ jobs:
         run: |
           curl -X POST $REDEPLOY_DEMO_URL
 
+      #-------------------------------------------------------------
+      # Build steps for PRs only
+      #
+      # These steps build the images and store as a build artifact.
+      # These artifacts can then be used by later jobs to run the
+      # brand-new images for automated testing.
+      #--------------------------------------------------------------
+      # Get Metadata for docker_build_deps step below
+      - name: Create metadata (tags, labels) for local Docker image
+        if: matrix.isPr
+        id: meta_build_pr
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.IMAGE_NAME }}
+          # Hardcode to use custom "pr-testing" tag because that will allow us to spin up this PR
+          # for testing in docker.yml
+          tags: pr-testing
+          flavor: ${{ env.TAGS_FLAVOR }}
+      # Build local image and stores in a TAR file in /tmp directory
+      - name: Build and push image to local image
+        if: matrix.isPr
+        uses: docker/build-push-action@v5
+        with:
+          build-contexts: |
+            ${{ inputs.dockerfile_additional_contexts }}
+          context: ${{ inputs.dockerfile_context }}
+          file: ${{ inputs.dockerfile_path }}
+          platforms: ${{ matrix.arch }}
+          tags: ${{ steps.meta_build_pr.outputs.tags }}
+          labels: ${{ steps.meta_build_pr.outputs.labels }}
+          # Export image to a local TAR file
+          outputs: type=docker,dest=/tmp/${{ inputs.build_id }}.tar
+      # Upload the local docker image (in TAR file) to a build Artifact
+      - name: Upload local image to artifact
+        if: matrix.isPr
+        uses: actions/upload-artifact@v4
+        with:
+          name: docker-image-${{ inputs.build_id }}
+          path: /tmp/${{ inputs.build_id }}.tar
+          if-no-files-found: error
+          retention-days: 1
+
   # Merge Docker digests (from various architectures) into a manifest.
   # This runs after all Docker builds complete above, and it tells hub.docker.com
   # that these builds should be all included in the manifest for this tag.
   # (e.g. AMD64 and ARM64 should be listed as options under the same tagged Docker image)
   docker-build_manifest:
+    # Only run if this is NOT a PR
     if: ${{ github.event_name != 'pull_request' }}
     runs-on: ubuntu-latest
     needs: