Kubernetes – kubectl command line utility

kubernetes components
kubernetes components

Hi All,

Greetings for the day 🙂 LIFE IS BEAUTIFUL 🙂

We are discussing Docker and Kubernetes. In previous few articles we discussed

Today we will discuss very important command line utility – kubectl

What is kubectl ?

What exactly happen when kubectl command is get executed ?

  • First understand the term Kubernetes API :
    • If we have a look below diagram, one of the core component of Kubernetes control plane is “kube API server”
    • API server exposes an HTTP API that allows users, different part of cluster and external components communicate with each other – we also called these API – Kubernetes API
    • Kubernetes API is an HTTP REST API
    • Kubernetes is fully controlled by these APIs
    • These Kubernetes API allows us to query and manipulate state of API objects in kubernetes like Pods, Namespaces, Configmaps and so on – kubernetes operations
    • All kubernetes operations exposes API end point
    • We can find API endpoint for all kubernetes in API references
    • So when we hit kubectl command kubectl makes HTTP POST request to respective operation API end point
  • kubectl uses these Kubernetes API, most of the operations are performed by kubectl
  • kubectl is CLI – command line interface which carries these HTTP API to the kubernetes API server as shown in below fig
kubernetes components / kubernetes architecture
Fig : kubernetes components / kubernetes architecture

Syntax for kubectl command:

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


  • command
    • Operation which we want to perform
    • Example : create, get, describe, delete etc
  • TYPE
    • Resource Type – Kubernetes objects
    • Example : pod, deployment, namespace, replicaset, ingress etc
    • To get all resource types we could execute CMDLET – kubectl api-resources
    • Resource types are case sensitive
    • we could specify singular , plural or abbreviated forms like pod / pods / po
  • NAME
    • Name of the resource
    • Name is case-sensitive
  • flags
    • Optional flags

Some important kubectl commands :

  • To get the cluster information
kubectl cluster-info

  • Create a following Kubernetes objects in default namespace :
    • Node
    • Pod
    • Replica Set
    • Deployment
kubectl create -f <Yammer definition file name of respective Kubernetes object>


kubectl create -f KnowledgeJunction-Pods-Definition-File.yaml

kubectl create -f KnowledgeJunction-ReplicaSets-Definition-File.yaml

kubectl create -f KnowledgeJunction-Depllyment-Definition-File.yaml

kubectl create -f KnowledgeJunction-Service-Definition-File.yaml

kubectl create -f KnowledgeJunction-Secret-Definition-File.yaml

  • To create kubernetes object in another namespace, we need to use –namespace option
kubectl create -f <Yammer definition file name of respective Kubernetes object> --namespace=<namespace name>

  • Get particular Kubernetes object lists from default namespace and hence the count
kubectl get <Kubernete Objects>

Example : 

kubectl get nodes
kubctl get pods
kubectl get replicasets
kubctl get deployments
kubectl get svc
kubectl get namespace
kubectl get secrets

  • To verify multiple objects lists from default namespace in one command, seperate kubernetes objects by comma
kubectl get <Kubernetes Objects>, <Kubernetes Objects>

Example : 

kubectl get pods, svc

  • To know the docker image used by Kubernetes object from default namespace use – -o wide option to kubctl get command
kubectl get <Kubernetes Objects>, <Kubernetes Objects> -o wide 


kubectl get pods
kubectl get pod pod1

  • To see all the kubernete objects from default namespace created at a time use – kubectl get all
kubectl get all

  • To list kubernetes object from another namespace use namespace option along with the name of namespace
kubectl get <Kubernetes Objects> -namespace=<namespace name>

  • Get details of Kubernetes object using describe parameter
kubectl describe <kubernetes object> <object-name>


kubectl describe deployment knowledgejunction-deployment # get the details of deployment kubernetes object - knowledjejunction deployment

  • Delete any kubernetes object
kubectl delete <objecttype> <objectname>


kubectl delete pod my-pod

  • Delete all Kubernetes objects
kubectl delete <objecttype> --all


kubectl delete pods --all

  • Check the status of Kubernetes Deployment object
kubectl rollout status deployment.apps/<deployment-name>


kubectl rollout status deployment.apps/knowledgeJunction-deployment

  • To check / verify the history of deployments
kubectl rollout history deployment.apps/<deployment-name>


kubectl rollout history deployment.apps/knowledgeJunction-deployment

  • To deploy application in cluster
kubectl run <application name> / <docker container>


kubectl run 

  • To switch the default namespace permanently use => kubectl config command with namespace parameter having namespace name
kubectl config set-context $(kubectl config current-context) --namespace=dev

Thanks for reading ! HAVE A FANTASTIC TIME AHEAD !!

Prasham Sabadra

LIFE IS VERY BEAUTIFUL :) ENJOY THE WHOLE JOURNEY :) Founder of Knowledge Junction and live-beautiful-life.com, Author, Learner, Passionate Techie, avid reader. Certified Professional Workshop Facilitator / Public Speaker. Scrum Foundation Professional certificated. Motivational, Behavioral , Technical speaker. Speaks in various events including SharePoint Saturdays, Boot camps, Collages / Schools, local chapter. Can reach me for Microsoft 365, Azure, DevOps, SharePoint, Teams, Power Platform, JavaScript.

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