rmenn / kping

kping

Simple webapp to demonstrate kubernetes health check failures & rolling deployments

Start the image on the cluster

kubectl create deployment test --image=rmenn/kping:0.0.1

Expose the deployment as a service

on minikube

kubectl expose deployment test --port=80 --type=LoadBalancer

minikube service test

on docker-for-mac

kubectl expose deployment test --port=80 --type=NodePort

Update the image version to 0.0.2

Running this in a split terminal will show you the real time updates

while true; do curl -m 0.5 -w "\t %{http_code} \n" <your_endpoint>/ping; done

Edit the manifest and update the image in the container spec

kubectl edit deployment/test

You should see a few timeouts occuring

Exercise - Add HealthChecks to the application. Endpoint is /healthz

health checks should remove the container from the service when it returns a non 2XX-3XX responce

to test this

curl -X POST <endpoint>/healthz

this will set the healthz endpoint to return an internal server error the pod will be restarted

Run curl and update the image 0.0.3