Introduce dropwizard/metrics integration test

.github/workflows/run-integration-tests.yml

@@ -2,21 +2,26 @@
 # against the project, using the code found on the pull request branch.
 # XXX: Generalize this to a matrix build of multiple integration tests,
 # possibly using multiple JDK or OS versions.
-# XXX: Investigate whether the comment can specify which integration tests run
-# run. See this example of a dynamic build matrix:
+# XXX: Investigate whether the comment can specify which integration tests run.
+# See this example of a dynamic build matrix:
 # https://docs.github.com/en/actions/learn-github-actions/expressions#example-returning-a-json-object
 name: "Integration tests"
 on:
+  pull_request:
+    branches: [ master ]
   issue_comment:
     types: [ created ]
 permissions:
   contents: read
 jobs:
   run-integration-tests:
-    name: On-demand integration test
-    if: |
-      github.event.issue.pull_request && contains(github.event.comment.body, '/integration-test')
     runs-on: ubuntu-24.04
+    #    if: github.event.issue.pull_request && contains(github.event.comment.body, '/integration-test')
+    # XXX: Configure permissions.
+    strategy:
+      matrix:
+        integration-test: [ "metrics", "checkstyle" ]
+    name: On-demand integration test
     steps:
       - name: Install Harden-Runner
         uses: step-security/harden-runner@91182cccc01eb5e619899d80e4e971d6181294a7 # v2.10.1
@@ -35,19 +40,20 @@ jobs:
       - name: Check out code and set up JDK and Maven
         uses: s4u/setup-maven-action@382542f77617f34e56bf83868920a4d45b7451e7 # v1.16.0
         with:
+          #          checkout-ref: "refs/pull/894/head"
           checkout-ref: "refs/pull/${{ github.event.issue.number }}/head"
           java-version: 17.0.13
           java-distribution: temurin
           maven-version: 3.9.9
       - name: Install project to local Maven repository
         run: mvn -T1C install -DskipTests -Dverification.skip
       - name: Run integration test
-        run: xvfb-run ./integration-tests/checkstyle.sh "${{ runner.temp }}/artifacts"
+        run: xvfb-run "./integration-tests/${{ matrix.integration-test }}.sh" "${{ runner.temp }}/artifacts"
       - name: Upload artifacts on failure
         if: ${{ failure() }}
         uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4.4.3
         with:
-          name: integration-test-checkstyle
+          name: "integration-test-${{ matrix.integration-test }}"
           path: "${{ runner.temp }}/artifacts"
       - name: Remove installed project artifacts
         run: mvn dependency:purge-local-repository -DmanualInclude='${project.groupId}' -DresolutionFuzziness=groupId