Kubernetes namespaces: concepts & key commands

Source: Dev.to

Introduction

What are Namespaces in Kubernetes?

• A namespace is a logical grouping of resources within a cluster.
• Useful for separating environments such as dev, staging, and prod.
• Helps avoid naming conflicts.
• Enables applying access control and resource quotas.
• Facilitates managing large clusters more effectively.
• Namespaces are logical only; they do not create separate clusters or nodes.

Important Things about Namespaces

• A Kubernetes cluster can contain multiple namespaces.
• Pods run on nodes, not inside namespaces.
• A single node can host Pods from multiple namespaces.
• Namespaces do not provide isolation by default.
• Resources like Pods, Deployments, and Services are namespace‑scoped.

Key namespace commands

List all namespaces

kubectl get namespaces

Lists every namespace present in the cluster.

Get Pods from a specific namespace

kubectl get pods -n 

Shows all Pods running in the specified namespace.

Create a namespace

kubectl create ns 

Creates a new namespace with the given name.

Create a Pod in the default namespace

kubectl run  --image=

Creates a Pod using the specified image in the default namespace.

Create a Pod in a specific namespace

kubectl run  --image= -n 

Creates a Pod using the specified image in the given namespace.

Delete a Pod from a namespace

kubectl delete pod  -n 

Removes the specified Pod from the indicated namespace.

Apply a YAML manifest

kubectl apply -f 

Creates or updates resources defined in the YAML file (declarative configuration).

Delete a namespace

kubectl delete namespace 

Deletes the namespace and all resources it contains. Use with caution.

Key takeaways

• Namespaces provide logical separation but not isolation.
• Use namespaces to organize resources, enforce RBAC, and set resource quotas.
• Common namespace‑scoped resources include Deployments, Services, and Pods.

What’s Next?

• Explore Deployments vs. Pods.
• Understand how controllers manage Pods.
• Study real‑world namespace usage patterns.

I’ll continue documenting my learning as I progress.