🌱 [backport release-0.3] Test image build when build related files change (#1907)

.github/workflows/ci-image-build.yml

@@ -0,0 +1,107 @@
+name: CI (test image build for a PR with build related changes)
+
+on:
+  pull_request:
+    branches:
+      - "main"
+      - "release-*"
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    outputs:
+      should-test: ${{ steps.check-changes.outputs.should-test }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: What files changed?
+        id: changed
+        uses: tj-actions/changed-files@v44
+        with:
+          files: |
+            Dockerfile
+            package-lock.json
+
+      - name: Check if build related files have been changed in a PR
+        id: check-changes
+        env:
+          IS_PR: ${{ !!github.event.pull_request }}
+          ANY_MODIFIED: ${{ steps.changed.outputs.any_modified }}
+        run: |
+          TEST_IMAGE_BUILD=$(
+            if [[ $IS_PR == true ]] && [[ $ANY_MODIFIED == true ]]; then
+              echo "true"
+            else
+              echo "false"
+            fi
+          )
+
+          echo "is-pr=$IS_PR" >> "$GITHUB_OUTPUT"
+          echo "changed=${ANY_MODIFIED:-false}" >> "$GITHUB_OUTPUT"
+          echo "should-test=$TEST_IMAGE_BUILD" >> "$GITHUB_OUTPUT"
+
+      - name: Summarize findings
+        env:
+          MODIFIED_FILES: ${{ steps.changed.outputs.all_modified_files }}
+        run: |
+          cat >> "$GITHUB_STEP_SUMMARY" <<EOF
+          ## Findings
+          PR triggered? \`${{ steps.check-changes.outputs.is-pr }}\`
+          PR includes a build file related change? \`${{ steps.check-changes.outputs.changed }}\`
+          Should the image build be tested? \`${{ steps.check-changes.outputs.should-test }}\`
+          EOF
+
+          if [[ -n "$MODIFIED_FILES" ]]; then
+            echo "## Build related modified files" >> "$GITHUB_STEP_SUMMARY"
+            for file in ${MODIFIED_FILES}; do
+              echo "  - \`$file\`" >> "$GITHUB_STEP_SUMMARY"
+            done
+          fi
+
+  #
+  # Based on:
+  #   - image-build.yaml
+  #   - konveyor/release-tools/.github/workflows/build-push-images.yaml@main
+  #
+  # Only test the image build, no push to quay is required.
+  #
+  test-image-build:
+    runs-on: ubuntu-latest
+    needs: checks
+    if: ${{ needs.checks.outputs.should-test == 'true' }}
+
+    strategy:
+      fail-fast: true
+      matrix:
+        architecture: # keep this list in sync with `image-build.yaml`
+          - "amd64"
+          - "arm64"
+          - "ppc64le"
+          - "s390x"
+
+    concurrency:
+      group: test-image-build-${{ matrix.architecture }}_${{ github.ref }}
+      cancel-in-progress: true
+
+    steps:
+      - name: Checkout merge commit for PR${{ github.event.pull_request.number }}
+        uses: actions/checkout@v4
+
+      - name: Setup QEMU to be able to build on ${{ matrix.architecture }}
+        if: ${{ matrix.architecture != 'amd64' }}
+        uses: docker/setup-qemu-action@master
+        with:
+          platforms: ${{ matrix.architecture }}
+
+      - name: Test build image on ${{ matrix.architecture }}
+        id: test-build
+        uses: redhat-actions/buildah-build@main
+        with:
+          image: "tackle2-ui"
+          tags: pr${{ github.event.pull_request.number }}-${{ matrix.architecture }}
+          extra-args: "--no-cache --rm --ulimit nofile=4096:4096"
+          archs: ${{ matrix.architecture }}
+          labels: ""
+          containerfiles: "./Dockerfile"
+          context: "."