14-pvc-deployment

GKE Workshop LAB-14

Introduction

In the following lab we will create a Redis deployment and a PersistentVolumeClaim, the Redis deployment will use the generated PersistentVolume to store data that will survive pod restarts. Stateful workloads should utilize StatefulSets, however, this lab demonstrates that any workload can utilize a volume if necessary.

Deployment

Run Deployment

kubectl apply -f .

Now we can check that our PersistentVolumeClaim is created:

kubectl get pvc --namespace doit-lab-14

And that the PVC created a Persistent Volume (using the Compute Engine persistent disk CSI Driver):

kubectl get pv

We'll wait for the Redis pod to come up

kubectl get po -w --namespace doit-lab-14

Once it's ready, let's run a shell inside it

kubectl -n doit-lab-14 exec -ti deployments/redis -- sh

List files within our data volume

ls -l /data

Let's check for the existence of a key in the DB

redis-cli get lab-14

We can see that it's not set (returning (nil)). Let's set it

redis-cli set lab-14 'Hello world!'

Exit the pod (Ctrl+D) and delete it. The deployment controller will start a new one

kubectl delete po -lk8s-app=redis -n doit-lab-14

Now let's exec into the newly created pod

kubectl -n doit-lab-14 exec -ti deployments/redis -- sh

And make sure that data was persisted across restarts

/data # redis-cli get lab-14
"Hello world!"

Application Clean-Up

kubectl delete ns doit-lab-14

Links

• https://cloud.google.com/kubernetes-engine/docs/concepts/persistent-volumes
• https://redis.io/docs/management/persistence/
• https://kubernetes.io/docs/reference/kubectl/cheatsheet/
• https://phoenixnap.com/kb/kubectl-commands-cheat-sheet