creating-and-managing-storage.md

Creating and managing storage

Storageclaims are the easiest to get some persistent storage to attach to pods wish survives deletion and upgrades of the pod. In this lab you will learn how to:

• Write a Storage claim configuration file
• Attach storage to a pod
• Remove storage

In this lab you will create a Pod named storage-monolith and a storage claim called monolith-storage.

Tutorial: Creating Storage claim

Explore the monolith-storage storage configuration file:

cat storage/monolith-storage.yaml

Create the monolith-storage storage using kubectl:

kubectl create -f storage/monolith-storage.yaml

Exercise: View Storage details

Use the kubectl get and kubectl describe commands to view details for the monolith-storage PersistentStorageClaim:

Hints

kubectl get pvc

kubectl describe pvc <StorageClaim>

Tutorial: Mount the storageclaim from a pod

Explore the storage-monolith pod configuration file:

cat pods/storage-monolith.yaml

Create the storage-monolith pod using kubectl:

kubectl create -f pods/storage-monolith.yaml

Ensure that the disk is mounted.

Hints

The describe command shows information about volume mount

Exercise: Touch a file on the volume

Use the kubectl exec command to run an interactive shell inside the monolith Pod:

kubectl exec storage-monolith --stdin --tty -c monolith -- /bin/sh
touch /var/tmp/storage/from_first_instance
ls /var/tmp/storage

Exercise: Remove the pod and recreate it and check if the file still exists

Hints

The kubectl delete command is used to remove a pod, kubectl delete -f file.yaml deletes all file defined in file.yaml

Bonus lab:

Checkout the statefulset directory, what happens when you create? How does it handle scale out? What do you think is the usecase for it?