ci: adjust owlbot-java for monorepo (#1500)

Author: suztomo

docker/owlbot/java/bin/entrypoint.sh

@@ -15,33 +15,83 @@
 
 set -e
 
-# templates
-echo "Generating templates..."
-/owlbot/bin/write_templates.sh
-echo "...done"
-
-# write or restore pom.xml files
-echo "Generating missing pom.xml..."
-/owlbot/bin/write_missing_pom_files.sh
-echo "...done"
-
-# write or restore clirr-ignored-differences.xml
-echo "Generating clirr-ignored-differences.xml..."
-/owlbot/bin/write_clirr_ignore.sh
-echo "...done"
-
-# fix license headers
-echo "Fixing missing license headers..."
-/owlbot/bin/fix_license_headers.sh
-echo "...done"
-
-# TODO: re-enable this once we resolve thrashing
-# restore license headers years
-# echo "Restoring copyright years..."
-# /owlbot/bin/restore_license_headers.sh
-# echo "...done"
-
-# ensure formatting on all .java files in the repository
-echo "Reformatting source..."
-/owlbot/bin/format_source.sh
-echo "...done"
+# Runs template and etc in current working directory
+function processModule() {
+  # templates
+  echo "Generating templates..."
+  /owlbot/bin/write_templates.sh
+  echo "...done"
+
+  # write or restore pom.xml files
+  echo "Generating missing pom.xml..."
+  /owlbot/bin/write_missing_pom_files.sh
+  echo "...done"
+
+  # write or restore clirr-ignored-differences.xml
+  echo "Generating clirr-ignored-differences.xml..."
+  /owlbot/bin/write_clirr_ignore.sh
+  echo "...done"
+
+  # fix license headers
+  echo "Fixing missing license headers..."
+  /owlbot/bin/fix_license_headers.sh
+  echo "...done"
+
+  # TODO: re-enable this once we resolve thrashing
+  # restore license headers years
+  # echo "Restoring copyright years..."
+  # /owlbot/bin/restore_license_headers.sh
+  # echo "...done"
+
+  # ensure formatting on all .java files in the repository
+  echo "Reformatting source..."
+  /owlbot/bin/format_source.sh
+  echo "...done"
+}
+
+if [ "$(ls */.OwlBot.yaml|wc -l)" -gt 1 ];then
+  # Monorepo (googleapis/google-cloud-java) has multiple OwlBot.yaml config
+  # files in the modules.
+  echo "Processing monorepo"
+  if [ -d owl-bot-staging ]; then
+    # The content of owl-bot-staging is controlled by Owlbot.yaml files in
+    # each module in the monorepo
+    echo "Extracting contents from owl-bot-staging"
+    for module in $(ls owl-bot-staging); do
+      if [ ! -d "$module" ]; then
+        continue
+      fi
+      # This relocation allows us continue to use owlbot.py without modification
+      # after monorepo migration.
+      mv "owl-bot-staging/$module" "$module/owl-bot-staging"
+      pushd "$module"
+      processModule
+      popd
+    done
+    rm -r owl-bot-staging
+  else
+    echo "In monorepo but no owl-bot-staging." \
+        "Formatting changes in the last commit"
+    # Find the files that were touched by the last commit.
+    last_commit=$(git log -1 --format=%H)
+    # [A]dded, [C]reated, [M]odified, and [R]enamed
+    changed_files=$(git show --name-only --no-renames --diff-filter=ACMR \
+        "${last_commit}")
+    changed_modules=$(echo "$changed_files" |grep -E '.java$' |cut -d '/' -f 1 \
+        |sort -u)
+    for module in ${changed_modules}; do
+      if [ ! -f "$module/.OwlBot.yaml" ]; then
+        # Changes irrelevant to Owlbot-generated module (such as .github) do not
+        # need formatting
+        continue
+      fi
+      pushd "$module"
+      processModule
+      popd
+    done
+  fi
+else
+  # Split repository
+  echo "Processing a split repo"
+  processModule
+fi