Advanced Kubernetes concepts

In this section, we will discuss other important Kubernetes features, including how to assign permanent storage to StatefulSets; how to store secrets such as passwords, connection strings, or certificates; how a container can inform Kubernetes about its health state; and how to handle complex Kubernetes packages with Helm. All of these subjects are organized into dedicated subsections. We will start with the problem of permanent storage.

Requiring permanent storage

Since Pods are moved between nodes, they can’t store data on the disk storage offered by the current node where they are running, or they would lose that storage as soon as they are moved to a different node. This leaves us with two options:

• Using external databases: With the help of databases, ReplicaSets can also store information. However, if we need better performance in terms of write/update operations, we should use distributed sharded databases based on non-SQL...