kubectl apply vs create in Kubernetes - CLI Comparison

Introduction

When managing applications on Kubernetes, you often need to add or update resources like pods or deployments. The commands kubectl create and kubectl apply help you do this, but they work differently. Understanding when to use each helps keep your cluster organized and up to date.

When you want to add a new resource to your cluster for the first time, like a new pod or service.

When you want to update an existing resource's configuration without deleting it first.

When you have a configuration file and want Kubernetes to track changes over time.

When you want to quickly create a resource without managing updates later.

When you want to automate updates in a safe way that merges changes.

Config File - pod.yaml

pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: example-pod
spec:
  containers:
  - name: nginx-container
    image: nginx:1.23
    ports:
    - containerPort: 80

This YAML file defines a simple Pod named example-pod running an Nginx container version 1.23. The apiVersion and kind specify the resource type. metadata sets the pod's name. spec describes the container details.

Commands

This command creates the pod defined in pod.yaml for the first time. It will fail if the pod already exists.

Terminal

kubectl create -f pod.yaml

Expected Output

pod/example-pod created

→

-f - Specifies the file containing the resource definition

This command lists all pods in the current namespace to verify that example-pod is running.

Terminal

kubectl get pods

Expected Output

NAME          READY   STATUS    RESTARTS   AGE

example-pod   1/1     Running   0          10s

This command creates the pod if it doesn't exist or updates it if it does, applying changes from pod.yaml.

Terminal

kubectl apply -f pod.yaml

Expected Output

pod/example-pod configured

→

-f - Specifies the file containing the resource definition

Check the pod status again to confirm the apply command worked and the pod is running.

Terminal

kubectl get pods

Expected Output

NAME          READY   STATUS    RESTARTS   AGE

example-pod   1/1     Running   0          20s

Key Concept

If you remember nothing else from this pattern, remember: use kubectl create to add new resources once, and kubectl apply to create or update resources safely over time.

Common Mistakes

Using kubectl create to update an existing resource

kubectl create will fail if the resource already exists, causing errors.

Use kubectl apply to update existing resources without errors.

Using kubectl apply without a configuration file

kubectl apply needs a file to know what to create or update; without it, the command fails.

Always provide a valid resource definition file with -f flag.

Summary

kubectl create adds a new resource and fails if it already exists.

kubectl apply creates or updates a resource, merging changes safely.

Use kubectl get pods to verify the resource status after creation or update.