Add Cloud java profiler to nomulus docker images (#2919)

* add cloud profiler to dockerfile and start script

* add apt-get update

* change in cb machine type for nomulus

* fix typo

* add max worker limit to gradle tests

* Switch to root before doing apt-get

* correct dockerfile

* jetty/Dockerfile

* profiler service conditional to kubernetes container name

jetty/Dockerfile

@@ -2,5 +2,16 @@ FROM jetty:12-jdk21
 ADD --chown=jetty:jetty build/jetty-base /jetty-base
 ADD --chown=jetty:jetty start.sh /
 ADD --chown=jetty:jetty logging.properties /
+
+USER root
+
+# Create a directory, download and extract the Cloud Profiler agent, version locked to "cloud-profiler-java-agent_20241028_RC00.tar.gz".
+RUN mkdir -p /opt/cprof && \
+    wget -q -O- https://storage.googleapis.com/cloud-profiler/java/cloud-profiler-java-agent_20241028_RC00.tar.gz\
+    | tar xzv -C /opt/cprof && \
+    chown -R jetty:jetty /opt/cprof
+
+USER jetty
+
 EXPOSE 8080
 ENTRYPOINT ["/bin/sh", "/start.sh"]

jetty/start.sh

@@ -21,6 +21,8 @@ cd webapps
 find . -maxdepth 1 -type d -name "console-*" -exec rm -rf {} +
 cd /jetty-base
 echo "Running ${env}"
-java -Dgoogle.registry.environment=${env} \
+# Use the CONTAINER_NAME variable from Kubernetes YAML to set the profiler service name.
+java -agentpath:/opt/cprof/profiler_java_agent.so=-cprof_service=${CONTAINER_NAME},-cprof_enable_heap_sampling=true \
+    -Dgoogle.registry.environment=${env} \
     -Djava.util.logging.config.file=/logging.properties \
     -jar /usr/local/jetty/start.jar