Attach JProfiler agent to a JVM running in a Kubernetes pod

k8s-jprofiler-attach.sh

#!/bin/bash
set -e

if [[ -z ${K8S_JVM_POD} ]]; then
    echo "K8S_JVM_POD not defined"
    exit 1
fi

EXEC="kubectl exec ${K8S_JVM_POD}"
CP="kubectl cp ${K8S_JVM_POD}"

if [[ -z ${K8S_JVM_PID} ]]; then
    echo "K8S_JVM_PID not defined, pick one:"
    ${EXEC} jps 2>/dev/null
    exit 1
fi

JPROFILER_PACKAGE=jprofiler_linux_10_1.tar.gz
JPROFILER_PACKAGE_URL=https://download-keycdn.ej-technologies.com/jprofiler/${JPROFILER_PACKAGE}

if [[ ! -f ${JPROFILER_PACKAGE} ]]; then
    wget -O "${JPROFILER_PACKAGE}" "${JPROFILER_PACKAGE_URL}"
fi

if ! ${EXEC} -- find /root/${JPROFILER_PACKAGE} &>/dev/null; then
    echo "${JPROFILER_PACKAGE} not found on the server, copying..."
    kubectl cp "${JPROFILER_PACKAGE}" "${K8S_JVM_POD}:/root/${JPROFILER_PACKAGE}"
else
    echo "${JPROFILER_PACKAGE}  already found in the server"
fi

JPROFILER_PORT=31757

${EXEC} -- tar -C /root -xf "/root/${JPROFILER_PACKAGE}"

${EXEC} -- /root/jprofiler10.1/bin/jpenable --pid=${K8S_JVM_PID} --port=${JPROFILER_PORT} --noinput --gui

This still works. I just needed the following:

• Your container image must have a JDK installed (JREs are not valid), as the JDK includes the jps binary used in the script. You can use ps instead to identify your process.
• You might need to change the JProfiler version to the one you are using locally.
• You might need to change the installation directory (currently /root) due to permissions.
• You need to run jpenable as a superuser. The easiest way to do this is to run the container as root (https://stackoverflow.com/a/48409635/14015237)

Once that's done, you need to attach your profiler to the container in the port specified (31757 by default). To accomplish this, I've found the easiest way to port forward the pod port to a local port:

kubectl port-forward <pod-name> 31757:31757

Leave the process running in the background and use your local JProfiler to attach a JVM in the address localhost:31757.

I hope this helps someone.

Need to fix L14

${EXEC} -- jps 2>/dev/null

The download link is broken. here is the new one
https://www.ej-technologies.com/download/jprofiler/files
or

https://download-gcdn.ej-technologies.com/jprofiler/jprofiler_linux_12_0_3.tar.gz