Having fun with containers with custom JVM args

container_jvm.md

• Create a temporary folder on the host machine

mkdir -p /tmp/output
chmod 777 /tmp/output

• Run the container

docker run -it --rm \
  --user jboss \
  --cpus="5.0" \
  --memory="1g" \
  -v /tmp/output:/home/jboss:Z \
  registry.access.redhat.com/ubi8/openjdk-8:1.15-1.1682399183 \
  /bin/bash

Within the container

pwd
java -XshowSettings:system -version
echo "public class CpuLoad { public static void main(String[] a) { long end = System.currentTimeMillis() + 60000; while (System.currentTimeMillis() < end) { Math.tan(Math.random()); } } }" > CpuLoad.java
javac CpuLoad.java
java -XshowSettings:system -XX:StartFlightRecording=duration=60s,filename=data.jfr CpuLoad