How to configure kubectl with a kubeconfig file

A kubeconfig file tells kubectl which cluster endpoint, user credentials, namespace, and context name to use for Kubernetes API requests. Keeping a received kubeconfig in its own file fits temporary or team-specific access from a cluster administrator or managed service without overwriting $HOME/.kube/config.

kubectl reads $HOME/.kube/config by default, but the KUBECONFIG environment variable or the --kubeconfig flag can point it at another file. A session-scoped KUBECONFIG value keeps the change limited to the active shell until the file and context have been checked.

A kubeconfig can contain credential material and can also reference external authentication commands. Use files only from a trusted cluster owner, restrict local permissions, select the intended context, and run a harmless read command before using the context for changes.

Steps to configure kubectl with a kubeconfig file:

Create the kubectl config directory if it is missing.
```
$ mkdir -p ~/.kube
```
Copy the received kubeconfig into a named file.
```
$ cp ~/Downloads/team-a.kubeconfig ~/.kube/team-a.kubeconfig
```
Use a descriptive filename for each cluster or team so shell history and error messages show which access file is active.
Restrict the kubeconfig file permissions.
```
$ chmod 600 ~/.kube/team-a.kubeconfig
```
A kubeconfig can include bearer tokens, client certificates, or exec-plugin settings. Do not use a file from an untrusted source.
Point the current shell at the saved kubeconfig file.
```
$ export KUBECONFIG=$HOME/.kube/team-a.kubeconfig
```
The export applies only to the current shell and child processes. Use --kubeconfig for one command when a shell-wide override is not needed.

List the contexts in the selected kubeconfig.

$ kubectl config get-contexts -o name
team-a-admin@team-a

Select the intended context.
```
$ kubectl config use-context team-a-admin@team-a
Switched to context "team-a-admin@team-a".
```
Use the exact context name listed by kubectl config get-contexts. This writes the current-context field in the selected kubeconfig file, not in $HOME/.kube/config.

Confirm the active context.

$ kubectl config current-context
team-a-admin@team-a

Verify read-only access through the configured file.
```
$ kubectl get namespace default
NAME      STATUS   AGE
default   Active   71s
```
If the cluster grants only namespace-scoped access, replace default with the namespace named by the cluster owner.

Author: Mohd Shakir Zakaria
Mohd Shakir Zakaria is a cloud architect with deep roots in software development and open-source advocacy. Certified in AWS, Red Hat, VMware, ITIL, and Linux, he specializes in designing and managing robust cloud and on-premises infrastructures.