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Managing Kubernetes Workloads with Namespaces:

In Kubernetes, namespaces provide a way to create virtual clusters within a physical cluster. They help segregate deployments based on teams, resources, or access control. When workloads run in different namespaces, they operate independently, even if they have the same name.

By default, there is no communication between namespaces unless explicitly configured. Resources can be allocated at the namespace level, allowing administrators to set resource quotas and limits for each namespace.

 

Default Namespaces in Kubernetes

Kubernetes comes with four default namespaces:

1. default – The default namespace for objects that are not assigned to a specific namespace.
2. kube-system – Used for Kubernetes system components (e.g., the scheduler, controller manager, and DNS).
3. kube-public – Readable by everyone in the cluster; used for publicly accessible information.
4. kube-node-lease – Holds lease objects associated with each node, improving node heartbeats.

Creating a Custom Namespace

If you need a custom namespace, you can define it in a YAML file:

apiVersion: v1
kind: Namespace
metadata:
  name: my-namespace

Apply the namespace using:

kubectl apply -f namespace.yaml

Example: Deploying a Pod in a Specific Namespace

To deploy a pod inside a custom namespace, specify the namespace field in your YAML file:

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
  namespace: my-namespace
spec:
  containers:
    - name: nginx-container
      image: nginx
Apply the deployment:
kubectl apply -f pod.yaml

Viewing and Managing Namespaces

List all namespaces:

     kubectl get namespaces

Get resources within a specific namespace:

   kubectl get pods -n my-namespace

Delete a namespace:

   kubectl delete namespace my-namespace

Conclusion

Namespaces are essential for organizing and isolating workloads in Kubernetes. They enable better resource management, security, and multi-tenancy within a cluster. By using namespaces effectively, teams can ensure their deployments remain structured and efficient.