How to Change Default Namespace using Kubectl?

In the dynamic world of Kubernetes, managing namespaces efficiently is crucial for orchestrating containerized applications. The default namespace is the space where resources are created if no specific namespace is mentioned. In this guide, we will explore the process of changing the default namespace using Kubectl, a powerful command-line tool for interacting with Kubernetes clusters.

1. Understanding Default Namespace in Kubernetes:

   Before diving into the process of changing the default namespace, it's essential to grasp the concept of namespaces in Kubernetes. Namespaces provide a way to organize and isolate resources within a cluster.

2. Checking Current Default Namespace:

   Begin by verifying the current default namespace to understand which namespace your Kubernetes cluster is using by default. Execute the following command in your terminal:

   kubectl config view | grep namespace
   

   This command will display the current default namespace.

3. Listing Available Namespaces:

   To get a list of all available namespaces in your Kubernetes cluster, use the following command:

   kubectl get namespaces
   

   This will give you an overview of the existing namespaces and their status.

4. Changing Default Namespace:

   Now, let's proceed with changing the default namespace. Use the following command to set a new default namespace:

   kubectl config set-context --current --namespace=<new-namespace>
   

   Replace <new-namespace> with the desired namespace.

5. Verifying the Change:

   To confirm that the default namespace has been successfully changed, re-run the command to check the current default namespace:

   kubectl config view | grep namespace
   

   The output should reflect the updated default namespace.

6. Switching Between Namespaces:

   Understanding how to switch between namespaces is equally important. Use the following command to switch to a different namespace temporarily:

   kubectl config set-context --current --namespace=<desired-namespace>
   

   Replace <desired-namespace> with the namespace you want to switch to.

7. More Examples:

   Here are a few additional examples to enhance your understanding:

   • To change the namespace when deploying a resource:

     kubectl create deployment nginx --image=nginx --namespace=<desired-namespace>
     

   • To specify the namespace in a YAML file:

     apiVersion: v1
     kind: Pod
     metadata:
       name: mypod
       namespace: <desired-namespace>
     

In this guide, we explored the process of changing the default namespace using Kubectl, a fundamental skill for Kubernetes administrators and developers. Proper namespace management contributes to a more organized and secure Kubernetes environment. By following the step-by-step instructions and examples provided, you can confidently navigate and manipulate namespaces within your Kubernetes cluster.