Kubernetes in the Enterprise

Chapter 3. Advanced Kubernetes Topics

In this chapter, we provide an overview of some of Kubernetes more advanced topics. We begin with a description of Kubernetes’ Service Object, which is its built-in facility for load balancing across Pod replicas. Next, we describe a few specialized options for managing Pod groups, including DaemonSets and StatefulSets. We then describe and provide examples of several advanced Kubernetes concepts, including Volumes, PersistentVolumes, ConfigMaps, Secrets, and image registry support. We conclude this chapter with a section on Helm, Kubernetes’ package manager, which enables you to create a package containing the multiple templates that make up your application.

Kubernetes Service Object: Load Balancer Extraordinaire

Kubernetes provides a Service Object as its mechanism for providing load balancing across Pod replicas. Upon first inspection, having this feature built in to Kubernetes might appear to be overkill because there are lots of open source load balancers already available. However, the high-level Pod replica management features Kubernetes provides necessitates it providing a custom load balancer for Pod replicas. As discussed in previous chapters, Kubernetes provides several high-level abstractions that are capable of starting new Pod replicas when needed. When this occurs, these Pod replicas might end up moving to different servers. Most load balancers that are available were not built to handle this high level of dynamism. Kubernetes ...