Chapter 6. Volumes: attaching disk storage to containers

In the previous three chapters, we introduced pods and other Kubernetes resources that interact with them, namely ReplicationControllers, ReplicaSets, DaemonSets, Jobs, and Services. Now, we’re going back inside the pod to learn how its containers can access external disk storage and/or share storage between them.

We’ve said that pods are similar to logical hosts where processes running inside them share resources such as CPU, RAM, network interfaces, and others. One would expect the processes to also share disks, but that’s not the case. You’ll remember that each container in a pod has its own isolated filesystem, because the file-system comes from the container’s image.

6.1. Introducing volumes

6.1.1. Explaining volumes in an example

6.1.2. Introducing available volume types

6.2. Using volumes to share data between containers

6.2.1. Using an emptyDir volume

6.2.2. Using a Git repository as the starting point for a volume

6.3. Accessing files on the worker node’s filesystem

6.3.1. Introducing the hostPath volume

6.3.2. Examining system pods that use hostPath volumes

6.4. Using persistent storage

6.4.1. Using a GCE Persistent Disk in a pod volume

6.4.2. Using other types of volumes with underlying persistent storage

6.5. Decoupling pods from the underlying storage technology

6.5.1. Introducing PersistentVolumes and PersistentVolumeClaims

6.5.2. Creating a PersistentVolume

6.5.3. Claiming a PersistentVolume by creating a PersistentVolumeClaim

6.5.4. Using a PersistentVolumeClaim in a pod

6.5.5. Understanding the benefits of using PersistentVolumes and claims

6.5.6. Recycling PersistentVolumes

6.6. Dynamic provisioning of PersistentVolumes

6.6.1. Defining the available storage types through StorageClass resources

6.6.2. Requesting the storage class in a PersistentVolumeClaim

6.6.3. Dynamic provisioning without specifying a storage class

6.7. Summary