Core Kubernetes

9 Running Pods: How the kubelet works

This chapter covers

• Learning what the kubelet does and how it’s configured
• Connecting container runtimes and launching containers
• Controlling the Pod’s life cycle
• Understanding the CRI
• Looking at the Go interfaces inside the kubelet and CRI

The kubelet is the workhorse of a Kubernetes cluster, and there can be thousands of kubelets in a production data center, as every node runs the kubelet. In this chapter, we’ll go through the internals of what the kubelet does and precisely how it uses the CRI (Container Runtime Interface) to run containers and manage the life cycle of workloads.

One of the kubelet’s jobs is to start and stop containers, and the CRI is the interface that the kubelet uses to interact ...