Mastering kubectl: Essential Commands and Tips for Kubernetes Management

kubectl Overview

kubectl is the command‑line tool for interacting with a Kubernetes cluster. It reads a config file from $HOME/.kube/config (or a file specified with --kubeconfig) and communicates with the API server to create, read, update, and delete resources.

Basic Syntax

kubectl [command] [TYPE] [NAME] [flags]

command : operation such as create, get, describe, delete, etc.

TYPE : resource type (case‑insensitive, singular, plural, or short name). Examples:

kubectl get pod pod1

kubectl get pods pod1

kubectl get po pod1

NAME : optional resource name; omitted lists all resources of the type.

flags : optional parameters, e.g., -s or --server to specify the API server address.

Specifying Multiple Resources

By type and name: kubectl get pod pod1 pod2 Mixed types: kubectl get pod/pod1 deployment/rc1 From files: kubectl get -f ./pod.yaml (YAML preferred over JSON).

Help

Run kubectl --help for the full help text.

Common Commands

annotate :

kubectl annotate (-f FILE | TYPE NAME) KEY=VAL ... [--overwrite] [--all]

api-versions : kubectl api-versions apply : kubectl apply -f FILE attach : kubectl attach POD -c CONTAINER [-i] [-t] autoscale :

kubectl autoscale (-f FILE | TYPE NAME) --min=MIN --max=MAX [--cpu-percent=CPU]

cluster-info : kubectl cluster-info config : kubectl config SUBCOMMAND create : kubectl create -f FILE delete : kubectl delete (-f FILE | TYPE NAME | TYPE/NAME) [flags] describe : kubectl describe TYPE NAME diff : kubectl diff -f FILE (beta)

edit : kubectl edit (-f FILE | TYPE NAME) exec :

kubectl exec POD [-c CONTAINER] [-i] [-t] -- COMMAND [args...]

explain : kubectl explain RESOURCE expose :

kubectl expose (-f FILE | TYPE NAME) [--port=PORT] [--type=TYPE]

get : kubectl get TYPE [NAME] [flags] label : kubectl label (-f FILE | TYPE NAME) KEY=VAL ... logs : kubectl logs POD [-c CONTAINER] [--follow] patch : kubectl patch (-f FILE | TYPE NAME) --patch PATCH port-forward : kubectl port-forward POD LOCAL:REMOTE [...] proxy : kubectl proxy [--port=PORT] replace : kubectl replace -f FILE run : kubectl run NAME --image=IMAGE [--port=PORT] [--dry-run=...] scale : kubectl scale (-f FILE | TYPE NAME) --replicas=N version :

kubectl version [--client]

Output Formatting

The default output is human‑readable text. Use -o or --output to select formats such as yaml, json, wide, or custom-columns.

kubectl get pod web-pod-13je7 -o yaml

Custom Columns

Define custom columns inline or via a file:

kubectl get pods my-pod -ocustom-columns=NAME:.metadata.name,RSRC:.metadata.resourceVersion

Or with a file:

kubectl get pods my-pod -ocustom-columns-file=template.txt

Server‑Side Columns

From Kubernetes 1.11+, the server can return specific columns. Disable with --server-print=false:

kubectl get pods my-pod --server-print=false

Sorting

Sort results with --sort-by=JSONPATH:

kubectl get pods -n kube-system --sort-by=.metadata.name

Resource Types

Supported resource types and short names can be listed with: kubectl api-resources Example output (Kubernetes 1.13.3) is shown in the image below:

Common Operation Examples

Apply a manifest kubectl apply -f example-service.yaml List pods kubectl get pods Describe a node kubectl describe node <node-name> Delete a pod by file kubectl delete -f pod.yaml Execute a command in a container kubectl exec my-pod -- /bin/bash Stream pod logs

kubectl logs -f my-pod