kubectl-cheatsheet

• Introduction
• Namespace
• Pods
• Replicasets
• Deployment
• ConfigMaps
• Secrets
• Imperative commands
• SSH into container
• Service Account

Introduction

https://kubernetes.io/docs/reference/kubectl/quick-reference/

Command	Purpose
kubectl get	Get summarized view of resources. Use -o for custom formats like json, yaml
kubectl describe	Get detailed information about a specific resource. Event & status section helpful for debugging
kubectl create	Creates a new resource. Fails if the resource already exists.
kubectl apply	Creates or updates a resource.
kubectl run	Creates & run single container pod on Kubernetes
kubectl expose	Creates service to expose pod or deployment or replicaset on Kubernetes
kubectl replace	Update an existing resource in a Kubernetes cluster

Namespace

kubectl get namespace
kubectl get ns
kubectl create namespace dev-ns

Pods

kubectl get pods
kubectl get pods -o wide
kubectl get po
kubectl delete pod <pod-name>
kubectl describe pod <pod-name>
kubectl get pods --all-namespaces
kubectl run redis --image=redis

Replicasets

kubectl get replicasets
kubectl get rs
kubectl get replicaset <replicaset-name> -o yaml
kubectl describe replicaset <replicaset-name>
kubectl create -f replicaset-definition.yaml
kubectl apply -f replicaset-definition.yaml
kubectl edit replicaset <replicaset-name>
kubectl scale replicaset <replicaset-name> --replicas=5
kubectl scale rs <replicaset-name> --replicas=5

Deployment

kubectl get deployment
kubectl get deploy
kubectl create deployment <deployment-name> --image=<image-name> --replicas=3

ConfigMaps

kubectl get configmaps
kubectl get cm
kubectl create configmap  webapp-config-map --from-literal=APP_COLOR=darkblue --from-literal=APP_OTHER=disregard

Secrets

kubectl get secrets
kubectl create secret generic webapp-config-map --from-literal=password=nidhish --from-literal=host=example.com

# NOTE: Secrets are NOT encrypted, but encoded.
# NOTE: Run below command in Linux to encode/decode
echo -n 'nidhish' | base64
echo -n 'bmlkaGlzaA==' | base64 --decode

Imperative-commands

# create a pod with redis image
kubectl run redis --image=redis

# Create a pod with name as redis, image as redis:alpine and label labelname=labelvalue
kubectl run redis -l labelkey=labelvalue --image=redis:alpine

# Create a service redis-service to expose the redis application within the cluster on port 6379
kubectl expose pod redis --port=6379 --name redis-service

# Create a deployment named webapp using the image kodekloud/webapp-color with 3 replicas
kubectl create deployment webapp --image=kodekloud/webapp-color --replicas=3

# Create a new namespace called dev-ns
kubectl create namespace dev-ns

# Create a pod called httpd using the image httpd:alpine in the default namespace. Next, create a service of type ClusterIP by the same name (httpd). The target port for the service should be 80
kubectl run httpd --image=httpd:alpine --port=80 --expose

SSH-into-container

SSH into app container

# Get list of pods
kubectl get po

# SSH into a pod
kubectl exec -it <pod-name> -- /bin/sh

# check environment variable of the pod (Optional)
env

# Get user of running pod
kubectl exec ubuntu-sleeper -- whoami

ServiceAccount

kubectl get serviceaccounts
kubectl get sa
kubectl create serviceaccount dashboard-sa
kubectl create token dashboard-sa