Anatomy of a `kubectl` Command

kubectl is the command-line interface for Kubernetes. It allows us to run commands against Kubernetes clusters. It is the most important command in Kubernetes, and we'll use it a lot.

I can't emphasize enough how important it is to write these commands manually until we internalize them. And, very importantly, make sure to set up kubectl completion, it will speed things up a lot.

$kubectlgetpodmy-pod-n my-namespace

Command

Specifies the operation that you want to perform on one or more resources, for example create, get, describe, delete.

Resource Type

Specifies the resource type. Resource types are case-insensitive and you can specify the singular, plural, or abbreviated forms.

Resource Name

Specifies the name of the resource. Names are case-sensitive. If the name is omitted, details for all resources are displayed, for example kubectl get pods.

Flags

Specifies optional flags. For example, you can use the -s or --server flags to specify the address and port of the Kubernetes API server.

Quick Reference

Common Commands

Command	What It Does	Example
get	List resources	kubectl get pods
describe	Show detailed info	kubectl describe pod my-pod
apply	Create or update from file	kubectl apply -f deployment.yaml
delete	Remove resources	kubectl delete pod my-pod
logs	View container logs	kubectl logs my-pod
exec	Run command in container	kubectl exec -it my-pod -- /bin/sh
port-forward	Forward local port to pod	kubectl port-forward my-pod 8080:80

Resource Shortcuts

Typing full resource names gets tedious. Use these shortcuts:

Full Name	Short	Example
pods	po	kubectl get po
services	svc	kubectl get svc
deployments	deploy	kubectl get deploy
namespaces	ns	kubectl get ns
configmaps	cm	kubectl get cm
persistentvolumeclaims	pvc	kubectl get pvc
nodes	no	kubectl get no

Output Formats

Control how results are displayed with -o:

kubectl get pods -o wide          # More columns (node, IP)
kubectl get pod my-pod -o yaml    # Full YAML definition
kubectl get pod my-pod -o json    # JSON format
kubectl get pods -o name          # Just names (for scripting)

Essential Flags

Flag	Purpose	Example
-n	Target namespace	kubectl get pods -n production
-A	All namespaces	kubectl get pods -A
-l	Filter by label	kubectl get pods -l app=web
-w	Watch for changes	kubectl get pods -w
-f	Use file	kubectl apply -f manifest.yaml
--dry-run=client	Preview without applying	kubectl apply -f x.yaml --dry-run=client

Common Patterns

Check what's running:

kubectl get pods
kubectl get all                   # Pods, services, deployments, etc.

Debug a failing pod:

kubectl describe pod <name>       # Check events
kubectl logs <name>               # Application logs
kubectl logs <name> --previous    # Logs from crashed container

Get into a container:

kubectl exec -it <pod> -- /bin/sh

Generate YAML templates:

kubectl create deployment nginx --image=nginx --dry-run=client -o yaml

Find available fields:

kubectl explain pod.spec.containers