ci: adding flatten plugin check (#530)

Fixes #525

.github/workflows/downstream-dependencies.yaml

@@ -27,3 +27,19 @@ jobs:
     - run: sudo apt-get update -y
     - run: sudo apt-get install libxml2-utils
     - run: .kokoro/client-library-check.sh ${{matrix.repo}} dependencies
+
+  flatten-plugin-check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-java@v3
+      with:
+        distribution: zulu
+        java-version: 11
+    - run: java -version
+    - run: sudo apt-get update -y
+    - run: sudo apt-get install libxml2-utils
+    - run: .kokoro/client-library-check.sh java-storage flatten-plugin
+      env:
+        REPO_TAG: v2.9.3
+        EXPECTED_DEPENDENCIES_LIST: java-storage-v2.9.3-expected-flattened-dependencies.txt

.kokoro/client-library-check.sh

@@ -52,7 +52,12 @@ echo "Version: ${VERSION}"
 
 # Check this BOM against a few java client libraries
 # java-bigquery
-git clone "https://github.com/googleapis/${REPO}.git" --depth=1
+if [ -z "${REPO_TAG}" ]; then
+  git clone "https://github.com/googleapis/${REPO}.git" --depth=1
+else
+  git clone "https://github.com/googleapis/${REPO}.git" --depth=1 --branch "${REPO_TAG}"
+fi
+
 pushd ${REPO}
 
 # replace version
@@ -69,6 +74,22 @@ dependencies)
     .kokoro/dependencies.sh
     RETURN_CODE=$?
     ;;
+flatten-plugin)
+    # This creates .flattened-pom.xml
+    .kokoro/build.sh
+    pushd google-cloud-*
+    mvn dependency:list -f .flattened-pom.xml -DincludeScope=runtime -Dsort=true \
+        | grep '\[INFO]    .*:.*:.*:.*:.*' |awk '{print $2}' > .actual-flattened-dependencies-list.txt
+    echo "Diff from the expected file (${EXPECTED_DEPENDENCIES_LIST}):"
+    diff "${scriptDir}/${EXPECTED_DEPENDENCIES_LIST}" .actual-flattened-dependencies-list.txt
+    RETURN_CODE=$?
+    if [ "${RETURN_CODE}" == 0 ]; then
+      echo "No diff."
+    else
+      echo "There was a diff."
+    fi
+    popd
+    ;;
 *)
     # This reads the JOB_TYPE environmental variable
     .kokoro/build.sh

.kokoro/java-storage-v2.9.3-expected-flattened-dependencies.txt

@@ -0,0 +1,33 @@
+com.fasterxml.jackson.core:jackson-core:jar:2.13.3:compile
+com.google.api-client:google-api-client:jar:1.35.1:compile
+com.google.api.grpc:proto-google-common-protos:jar:2.9.0:compile
+com.google.api.grpc:proto-google-iam-v1:jar:1.4.1:compile
+com.google.api:api-common:jar:2.2.1:compile
+com.google.api:gax-httpjson:jar:0.103.2:compile
+com.google.api:gax:jar:2.18.2:compile
+com.google.apis:google-api-services-storage:jar:v1-rev20220705-1.32.1:compile
+com.google.auth:google-auth-library-credentials:jar:1.7.0:compile
+com.google.auth:google-auth-library-oauth2-http:jar:1.7.0:compile
+com.google.auto.value:auto-value-annotations:jar:1.10:compile
+com.google.cloud:google-cloud-core-http:jar:2.8.0:compile
+com.google.cloud:google-cloud-core:jar:2.8.0:compile
+com.google.code.findbugs:jsr305:jar:3.0.2:compile
+com.google.code.gson:gson:jar:2.9.0:compile
+com.google.guava:failureaccess:jar:1.0.1:compile
+com.google.guava:guava:jar:31.1-jre:compile
+com.google.guava:listenablefuture:jar:9999.0-empty-to-avoid-conflict-with-guava:compile
+com.google.http-client:google-http-client-apache-v2:jar:1.42.0:compile
+com.google.http-client:google-http-client-appengine:jar:1.42.0:compile
+com.google.http-client:google-http-client-gson:jar:1.42.0:compile
+com.google.http-client:google-http-client-jackson2:jar:1.42.0:compile
+com.google.http-client:google-http-client:jar:1.42.0:compile
+com.google.j2objc:j2objc-annotations:jar:1.3:compile
+com.google.oauth-client:google-oauth-client:jar:1.34.1:compile
+com.google.protobuf:protobuf-java-util:jar:3.21.1:compile
+com.google.protobuf:protobuf-java:jar:3.21.1:compile
+io.grpc:grpc-context:jar:1.47.0:compile
+io.opencensus:opencensus-api:jar:0.31.1:compile
+io.opencensus:opencensus-contrib-http-util:jar:0.31.1:compile
+javax.annotation:javax.annotation-api:jar:1.3.2:compile
+org.checkerframework:checker-qual:jar:3.22.2:compile
+org.threeten:threetenbp:jar:1.6.0:compile