/kubernetes-liveness-probes

Kubernetes Liveness Probes

Step 1: Implement Liveness Probe Health Checks

  • The API being a crucial part of the application it needs to be highly available

Step 1.1: Configure the Probe

$ mkdir -p ~/environment/healthchecks
$ cat <<EoF > ~/environment/healthchecks/liveness-app.yaml
apiVersion: v1
kind: Pod
metadata:
  name: liveness-app
spec:
  containers:
  - name: liveness
    image: jrdalino/calculator-backend
    livenessProbe:
      httpGet:
        path: /health
        port: 5000
      initialDelaySeconds: 5
      periodSeconds: 5
EoF

Step 1.2: Create the pod using the manifest

$ kubectl apply -f ~/environment/healthchecks/liveness-app.yaml
$ kubectl get pod liveness-app
$ kubectl describe pod liveness-app

Step 1.3: Introduce a Failure to Test

$ kubectl exec -it liveness-app -- /bin/kill -s SIGUSR1 1
$ kubectl get pod liveness-app
$ kubectl logs liveness-app
$ kubectl logs liveness-app --previous

(Optional) Clean Up

$ kubectl delete -f ~/environment/healthchecks/liveness-app.yaml