Pod Life Cycle and Kubernetes Components

The previous sections in this chapter briefly described the Kubernetes components and how they work internally with each other. On the other hand, we also demonstrated how to use some Kubernetes API objects (Pods, Services, and Deployments) to compose your applications.

But how is a Kubernetes API object managed by different Kubernetes components? Let's consider a pod as an example. Its life cycle can be illustrated as follows:

Figure 2.20: The process behind the creation of a pod

This entire process can be broken down as follows:

1. A user starts to deploy an application by sending a Deployment YAML manifest to the Kubernetes API server. The API server verifies the request and checks whether it's valid. If it is, it persists the Deployment API object to its backend datastore (etcd).

   Note

   For any step that evolves by modifying API objects, interactions have to happen between etcd and the API server, so...