Kubernetes Deployments

In this chapter, we’ll learn about the Kubernetes Deployment object and use it to make the sample app resilient.

The chapter is organized as follows:

• Introduction to Kubernetes Deployments

• Self-heal from a Pod failure

• Self-heal from a worker node failure

Let’s start with Kubernetes Deployment.

What is a Deployment object?

Kubernetes has lots of objects that add features and capabilities. In the previous chapter, we used a Service object to provide network connectivity. In this chapter, we’ll use a Deployment object to add self-healing. In fact, in the next few chapters, we’ll use the same Deployment object to perform scaling and rolling updates.

As with Pods and Services, Deployments are defined in YAML manifest files. The following figure shows the Deployment manifest we’ll use. It’s marked up to show the container nested in the Pod and the Pod nested in the Deployment.