Mastering Kubernetes Components: Namespace, ConfigMap, and Secrets

In Kubernetes, effective management of namespaces, ConfigMaps, and Secrets is crucial for maintaining a well-organized and secure environment. Let's explore key commands and concepts related to these components.

Namespace Operations

View Namespaces
List all namespaces in the current cluster:

kubectl get ns

Create a Namespace
Create a new namespace, either imperatively or declaratively:

kubectl create ns <namespace-name>
kubectl apply -f <namespace.yaml>

View Pods in a Namespace
Check pods in a specific namespace:

kubectl get po -n kube-system

Describe a Namespace
Get detailed information about a specific namespace:

kubectl describe ns <namespace-name>

Delete a Namespace
To delete a specific namespace:

kubectl delete ns <namespace-name>

Switch Namespace Permanently
Set the current context to a specific namespace:

kubectl config set-context $(kubectl config current-context) --namespace=<namespace-name>

View Pods in All Namespaces
List all pods across all namespaces:

kubectl get po -A

Create a Pod in a Specific Namespace
Run a pod in a designated namespace:

kubectl run redis --image=redis -n <namespace-name>

Create Namespace Declaratively
Create a namespace from a YAML file:

kubectl create ns <namespace-name> --dry-run=client -o yaml > namespace.yaml
kubectl apply -f namespace.yaml

ConfigMap Operations

View ConfigMaps
List all ConfigMaps in the current namespace:

kubectl get cm

Describe a ConfigMap
Get detailed information about a specific ConfigMap:

kubectl describe cm <cm-name>

Create a ConfigMap
Create a ConfigMap from files or literals:

kubectl create cm <cm-name> --from-file=<path to file>
kubectl create cm <cm-name> --from-literal=<key1>=<value1> --from-literal=<key2>=<value2>
kubectl apply -f cm.yaml

Secret Operations

View Secrets
List all secrets in the current namespace:

kubectl get secrets

Describe a Secret
Get detailed information about a specific Secret:

kubectl describe secret <secret-name>

Create a Secret
Create a Secret from files or literals:

kubectl create secret generic <secret-name> --from-file=<path to file>
kubectl create secret generic <secret-name> --from-literal=<key1>=<value1> --from-literal=<key2>=<value2>

Encoding and Decoding Secrets

Use base64 for encoding and decoding secrets:

echo -n 'string' | base64
echo -n 'encoded string' | base64 --decode

Ensure proper management of namespaces, ConfigMaps, and Secrets to achieve effective resource isolation, configuration management, and sensitive data protection in your Kubernetes cluster.

Happy Kuberneting!