Framstag / KubeTestPod

Simple do-nothing Pod for Kubeernetes written in Go to for simple testing purposes

Why?

I needed a simple, fast to compile, install and modify Container/POD for Kubernetes with some logging, health checks and a way to get it to die by curl call for simple tests of Kubernetes resilience logic.

I have tested it under ArchLinux using minikube.

How?

Build application

Call the buildGo.sh to compile the Go binary. The script set CGO_ENABLED=0 to avoid differences between the build system and the Docker system (like having different libc implementations).

Build docker image

Call buildDocker.sh to build the Docker file and move into the registry. For minikube call

eval $(minikube docker-env)

to place the Docker image directly into the minikube registry.

Get it into Kubernetes

• (Optionally) Patch the deployment.yaml for your needs
• (Optionally) Create a namespace: kubectl create namespace minitestpod
• Import the yaml: kubectl create -f deployment.yaml

Endpoints

• / - a nice hello world response
• /liveness - a HTTP 200 OK
• /readiness - a HTTP 200 OK
• /die - Immediate OS.exit(), Kubernetes should detect this and should restart the POD

Environment

• NAME - Change the name in the log messages
• PORT - Change the port of the internl HTTP server

Kill it

curl --header "Host:kubetestpod.example.com" 192.168.99.100/die

(You need the header to get the ingress working in cases where DNS resolving is not activated)

Kubernetes helper

Get the pods

kubectl get pods --namespace kubetestpod

Get the ingress (access form the outside)

kubectl get ingress --namespace kubetestpod

Get the events

kubectl get events --namespace kubetestpod

Get the logs (pod name and namespace may be different)

kubectl logs -f kubetestpod-6877f6945b-tgx77 --namespace kubetestpod

Words of warning

Go is not my first language.

Help

Patches welcome!