wigwam/kubster repository overview

⁠Kubster

Kubster is a simple http server that can be used to demonstrate k8s liveness and readiness probes' concept.

⁠API

• GET / - always returns 200 OK and print nice k8s logo
• GET /live - returns 200 OK (default) or 503 Service Unavailable (if set)
• GET /ready - returns 503 Service Unavailable after start, changes to 200 OK after KUBSTER_READYDELAY number of seconds (default), or can be overriden
• GET /set?live=<true|false>&ready=<true|false> - override /live and /ready endpoint responses (true for 200 OK, false for 503 Service Unavailable)

⁠Configuration

Environment variables:

• KUBSTER_BIND - host:port to bind to and listen on
• KUBSTER_READYDELAY - number of seconds before the /ready endpoint starts succeeding

⁠Kubernetes

Clone this repo and make it your current working directory first.

# Create the pod first, the pod name will be kubster-pod
kubectl apply -f manifests/pod.yaml

# Run multiple times to observe how pods gets ready after 30 seconds from launching
kubectl describe pod kubster-pod

# You can use port forwarding to access the http server and view/modify the responses
kubectl port-forward kubster-pod 8080:8080 &
curl -s localhost:8080/
curl -sv localhost:8080/live
curl -sv localhost:8080/ready

# Make kubernetes restart the pod
curl -s localhost:8080/set?live=false