K8s-debug

This repo contains a demo application that can be used to showcase interactive K8s debug containers.

Ingress

Ingress-nginx can be deployed by executing the following helm command.

helm upgrade --install ingress-nginx ingress-nginx \
--repo https://kubernetes.github.io/ingress-nginx \
--namespace ingress-nginx --create-namespace

Application

The application needs to be built before deploying it to k8s.

Build application

If necessary adjust the dockerClient in the build.gradle file.

./gradlew clean build jibDockerBuild

Deploy application

cd charts
helm upgrade --install k8s-debug k8s-debug
cd -

Port forwarding

kubectl port-forward --namespace=ingress-nginx service/ingress-nginx-controller 8080:80

Testing the API

curl http://localhost:8080/data

Enable namespace sharing in the pod to debug

spec:
  shareProcessNamespace: true
  containers:
    ...

Run debug pod

kubectl debug $(kubectl get pods -l app=k8s-debug --no-headers -o custom-columns=":metadata.name") -it --image=cschaible/jcmd-tui:0.1.0 --share-processes -- /bin/bash

# Get process id
$ ps ax

# Run jcmd_tui
$ jcmd_tui --attach <PID>

# Run jcmd directly
$ jattach <PID> jcmd VM.native_memory