Jump right into Kubernetes development with career-focused lessons and hands-on practice.

DevOps for Developers

Kubernetes is a powerful container management tool that's taking the world by storm. This detailed course will help you master it.

In this course, you'll start with the fundamentals of Kubernetes and what the main components of a cluster look like. You'll then learn how to use those components to build, test, deploy, and upgrade applications, as well as how to achieve state persistence once your application is deployed. You'll also learn how to secure your deployments and manage resources, which are crucial DevOps skills.

By the time you're done, you'll have a firm grasp on what Kubernetes is, as well as the skills to deploy your own clusters and applications with confidence.

A Practical Guide to Kubernetes

# Static volume provisioning

So far, we’ve used static PersistentVolumes. We had to create both EBS volumes and Kubernetes PersistentVolumes manually. Only after both became available were we able to deploy Pods that mounted those volumes through PersistentVolumeClaims. We’ll call this process static volume provisioning.

In some cases, static volume provisioning is a necessity. Our infrastructure might not be capable of creating dynamic volumes. That is often the case with on-premise infrastructure with volumes based on Network File System (NFS). Even then, with a few tools, a change in processes, and the right choices for supported volume types, we can often reach the point where volume provisioning is dynamic. Still, that might prove to be a challenge with legacy processes and infrastructure.

Since our cluster is in AWS, we cannot blame legacy infrastructure for provisioning volumes manually. Indeed, we could have jumped straight into this section. After all, AWS is all about dynamic infrastructure management.

However, we felt it would be easier to understand the processes by exploring manual provisioning first. The knowledge we obtained will help us understand better what’s coming next.
 

The second reason is that we may run a Kubernetes cluster on infrastructure that has to be static. Even though we’re using AWS for the examples, everything you learned this far can be implemented on static infrastructure. You’ll only have to change EBS with NFS and review the [NFSVolumeSource](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.10/#nfsvolumesource-v1-core) 
 documentation. 
There are only three NFS-specific fields, so we should be up and running in no time.

Before we discuss how to enable dynamic persistent volume provisioning, we should understand that it will be used only if none of the static PersistentVolumes match our claims. In other words, Kubernetes will always select statically created PersistentVolumes over dynamic ones.

# Dynamic volume provisioning
Dynamic volume provisioning allows us to create storage on demand. Instead of manually pre-provisioning storage, we can provision it automatically when a resource requests it.

We can enable dynamic provisioning through the usage of StorageClasses from the `storage.k8s.io` API group. They allow us to describe the types of storage that can be claimed. 

On the one hand, a cluster administrator can create as many StorageClasses as there are storage flavors. On the other hand, the users of the cluster do not have to worry about the details of each available external storage. It's a win-win situation where the administrators do not have to create PersistentVolumes in advance, and the users can simply claim the storage type they need.
## StorageClasses
To enable dynamic provisioning, we need to create at least one StorageClass object. Luckily for us, kOps already set up a few, so we might just as well look at the StorageClasses currently available in our cluster.

Learn how to provision PersistentVolumes dynamically by using storage classes.

Using Storage Classes to Dynamically Provision Persistent Volumes

Static volume provisioning