CKA - Personal Notes

Reference: Official kubectl command conventions – https://kubernetes.io/docs/reference/kubectl/conventions/

Command	What It Does	When I Use It
`kubectl run nginx-pod --image=nginx --restart=Never`	Creates a single Pod directly (not a Deployment).	When the task explicitly asks for a Pod quickly.
`kubectl describe pod nginx-pod`	Prints the resource details, status conditions, and recent events so I can diagnose issues.	When pods, services, or other objects misbehave and I need the full state and events in one view.
`kubectl explain pod.spec`	Shows the schema, required fields, and field descriptions for core API objects.	When I need to recall the exact field names, types, or nested structure while editing manifests in a hurry.
`kubectl get pods -o wide`	Shows extra pod details like node and pod IP.	Quick troubleshooting and placement checks.
`kubectl expose deployment nginx --port=80 --target-port=8080 --type=ClusterIP`	Wraps an existing Deployment with a Service so its pods are reachable inside/outside the cluster depending on `type`.	When I need to quickly expose HTTP workloads to other pods or create an exam service with minimal YAML.
`kubectl explain pod --recursive \u2502 less`	Dumps the entire pod schema and subfields so you can page through the hierarchy without re-running the command.	When I need to explore every nested field of pods or study the schema without my terminal scrolling away.
`kubectl run test-pod --image=busybox --restart=Never -- sleep 3600`	Creates a long-running test Pod for debug/exec checks.	Network/DNS/connectivity validation in-cluster.
`kubectl run web --image=nginx --restart=Never --dry-run=client -o yaml > pod.yaml`	Generates a Pod manifest without creating it.	Fast YAML scaffolding during exam tasks.
`kubectl create deployment httpd-frontend --image=httpd:2.4-alpine --dry-run=client -o yaml > httpd-frontend.yaml`	Emits the Deployment YAML without applying it so I can review or hand-edit before creation.	When I need create deployment manifests quickly but control the exact spec before handing it to the cluster.
`kubectl replace -f my-replicaset.yaml`	Replaces the ReplicaSet manifest atomically so the existing object updates in place.	When I need to shift the pod template, labels, or container spec without tearing the ReplicaSet down.
`kubectl scale rs my-app --replicas=5`	Changes the desired replica count of the ReplicaSet so the controller adjusts pods immediately.	During load spikes, debugging sessions, or when pods drop below the expected count and need a quick restore.