Understanding the concept of context and how to use it with kubectl

Ok, let's start from the beginning.

To understand what a context is, we first need to understand that many software tools use a configuration file to connect to the Kubernetes API. This configuration file contains three main pieces of information:

Clusters: The clusters section contains all the connection details to the different Kubernetes API servers available.
Users: Here we can define all the authentication data, like client-certificate and client-key
Context: The context ("The reason for this tutorial") is where we define what cluster and user we are goin to use to create the connection and optionally we can also define the namespace we want interact with.

The kubeconfig file (usually located at ~/.kube/config) typically includes:

apiVersion: v1
kind: Config
clusters:
- name: dev-cluster
  cluster:
    server: https://dev.k8s.example.com
    certificate-authority: /path/to/ca.crt

users:
- name: dev-user
  user:
    client-certificate: /path/to/dev.crt
    client-key: /path/to/dev.key

contexts:
- name: dev-context
  context:
    cluster: dev-cluster
    user: dev-user
    namespace: development

current-context: dev-context

Why Are Contexts Structured This Way?

By separating clusters, users, and contexts, the kubeconfig file lets you:

Reuse components (e.g., connect the same cluster with different users)
Easily create a new context without duplicating config
Manage Kubernetes workflows in a modular way

This separation gives you flexibility when scripting, automating, or managing large multi-cluster environments.

Essential kubectl Context Commands

Here we are going to list everything you need to know to manage contexts with kubectl:

1. List all available contexts

kubectl config get-contexts

Lists all contexts in your kubeconfig. The current context is marked with *.

2. View the current context

kubectl config current-context

Displays the name of the active context.

3. Switch to a different context

kubectl config use-context <context-name>

Changes the active context to the one specified.

4. Set the default namespace for the current context

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

Sets a default namespace for your active context. This helps avoid needing --namespace in every command.

5. Creating or Modifying a Context

You can create or update a context like this:

kubectl config set-context <context-name> \
--cluster=<cluster-name> \
--user=<user-name> \
 --namespace=<namespace>

Use this to script environment setups or define custom workflows.

Things to Remember:

Use clear and descriptive names: e.g., dev-cluster, prod-eks, test-gke
Install tools like kubectx for quick switching
Always double-check your current context before running critical commands
Back up your kubeconfig file, especially when working with production

Conclusion

Mastering kubectl context management allows you work securely and efficiently across environments. Whether you’re switching between cloud providers or staging and production clusters, contexts give you control and flexibility.

Mastering kubectl Context in Kubernetes