Working with Contexts and Kubeconfig

1. Viewing Current Context

Command	Description	Example
kubectl config current-context	Displays the current context name	`kubectl config current-context`
kubectl config view	Displays the full kubeconfig file content	`kubectl config view`
kubectl config view -o json	Displays the kubeconfig in JSON format	`kubectl config view -o json`

Example: Current Context Output

minikube

Note: The current context is used by default when running kubectl commands unless specified otherwise.

2. Listing All Contexts

Command	Description	Example
kubectl config get-contexts	List all contexts in the kubeconfig file	`kubectl config get-contexts`
kubectl config get-contexts -o name	Output only context names	`kubectl config get-contexts -o name`
kubectl config get-contexts --no-headers	Display contexts without headers	`kubectl config get-contexts --no-headers`

Example: Output of kubectl config get-contexts

CURRENT   NAME           CLUSTER        AUTHINFO       NAMESPACE
*         minikube       minikube       minikube
          kind-kind      kind-kind      kind-admin
          docker-desktop docker-desktop docker-desktop

3. Switching Contexts

Context Field	Description	Example Value
name	Unique identifier for the context	`production`
cluster	Name of the cluster to use	`production-cluster`
user	Name of the user to authenticate as	`admin`

Example: Switching Contexts

kubectl config use-context production

Note: The context must exist in your kubeconfig file to switch to it.

Example: Viewing Current Context

kubectl config current-context

Example: Listing All Contexts

kubectl config get-contexts

4. Creating New Context

Example: Create a new context using kubectl

kubectl config set-context my-cluster --cluster=production-cluster --user=prod-user

Option	Description	Usage
--cluster	Name of the cluster to use in the context	`kubectl config set-context my-context --cluster=production-cluster`
--user	Name of the user to use in the context	`kubectl config set-context my-context --user=prod-user`
--namespace	Default namespace to use in the context	`kubectl config set-context my-context --namespace=default`

Note: The new context is automatically set as the current context if you do not specify --current.

5. Renaming Contexts

Operation	Description	Command	Notes
kubectl config rename-context	Renames a context in kubeconfig	`kubectl config rename-context <old-name> <new-name>`	Updates the kubeconfig file directly

Example: Renaming a Context

kubectl config rename-context prod-cluster prod-staging

Note: The context name must be unique within the kubeconfig file. Ensure no other context uses the new name before renaming.

6. Deleting Contexts

Context Property	Description	Value Example
name	Name of the context to delete	`my-context`

Example: Delete a Context

kubectl config delete-context my-context

Note: Deleting a context removes the association between the context name and its configuration, but does not delete the actual cluster or user credentials.

7. Setting Context Namespace

Property	Description	Value
namespace	The default namespace for resources in this context	`default`

Example: Setting Namespace in kubeconfig

apiVersion: v1
clusters:
- cluster:
    server: https://kubernetes.example.com
  name: production
contexts:
- context:
    cluster: production
    namespace: frontend-app
    user: admin
  name: prod-frontend
current-context: prod-frontend
users:
- name: admin
  user:
    client-certificate-data: <cert-data>
    client-key-data: <key-data>

Note: Setting the namespace in a context affects all commands run with that context. It does not change the actual namespace of existing resources.

8. Merging Kubeconfig Files

Example: Merge kubeconfig files

kubectl config view --raw | kubectl config merge <file1> <file2>

Option	Description	Usage
--raw	Output raw kubeconfig content without merging	`kubectl config view --raw`
--merge	Merge multiple kubeconfig files into one	`kubectl config merge <file1> <file2>`

Note: Merging kubeconfig files can overwrite existing configurations. Always backup your current config before merging.

9. Viewing Kubeconfig Content

Example: Display current kubeconfig

kubectl config view

Field	Description	Example Value
clusters	List of cluster configurations	`[{"cluster": {"certificate-authority-data": "...", "server": "https://k8s.example.com"}, "name": "prod-cluster"}]`
contexts	List of context configurations	`[{"context": {"cluster": "prod-cluster", "user": "admin"}, "name": "prod-context"}]`
users	List of user configurations	`[{"name": "admin", "user": {"client-certificate-data": "...", "client-key-data": "..."}}]`

Example: View specific context

kubectl config view --context=prod-context

Example: Show current context

kubectl config current-context

Note: The kubeconfig file is typically located at ~/.kube/config.

10. Setting Cluster Server

Property	Value	Description
clusters.name	`my-cluster`	Name of the cluster as defined in kubeconfig
clusters.cluster.server	`https://192.168.1.100:6443`	API server URL for the cluster

Example: Setting Cluster Server URL

clusters:
- cluster:
    server: https://192.168.1.100:6443
  name: my-cluster

11. Setting User Credentials

Property	Description	Example
user.name	Name of the user	`admin`
user.client-certificate	Path to client certificate file	`/path/to/client.crt`
user.client-key	Path to client key file	`/path/to/client.key`
user.token	Authentication token	`eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...`
user.username	Username for basic auth	`admin`
user.password	Password for basic auth	`secret123`

Example: Configure User Credentials

apiVersion: v1
kind: Config
clusters:
- cluster:
    server: https://k8s.example.com
  name: example-cluster
contexts:
- context:
    cluster: example-cluster
    user: admin-user
  name: example-context
current-context: example-context
users:
- name: admin-user
  user:
    client-certificate: /path/to/client.crt
    client-key: /path/to/client.key

Note: Ensure the paths to certificate and key files are correct and accessible by the kubeconfig file.