Pods: The Smallest Deployable Unit

Every workload in Kubernetes (Deployment, DaemonSet, StatefulSet, Job) is ultimately a template for creating Pods. When you write a Deployment manifest, what you're really writing is a Pod spec wrapped in a controller. Understanding the Pod spec directly isn't optional for the CKAD exam: it appears in virtually every task. This article covers the Pod spec, lifecycle, probes, and how to run, inspect, and debug Pods with kubectl.

The Pod spec is the contract between you and the container runtime. Every field in spec.containers[] maps directly to how kubelet runs the container: image, command, args, ports, env, resources, securityContext. You schedule Pods (not containers), and the scheduler places the Pod on a node where the kubelet creates and manages its containers.