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Rohan Nalawade
Rohan Nalawade

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Kubernetes namespaces: concepts & key commands

#kubernetes #devops #docker #containers

Introduction
As part of my Kubernetes learning journey, today I focused on understanding Namespaces — what they are, why they exist, and how to work with them using basic kubectl commands.
I have written down my current understanding of namespaces and the commands I practiced hands-on.

What are Namespaces in Kubernetes?

A namespace in Kubernetes is a logical grouping of resources within a cluster.
Namespaces help organize resources and make it easier to:

  • Separate environments (dev, staging, prod)
  • Avoid naming conflicts
  • Apply access control and quotas
  • Manage large clusters more effectively Namespaces are logical, not physical. They do not create separate clusters or nodes.

Important Things about Namespaces

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

Key namespace commands i learned today
Below are the core commands I practiced while learning namespaces.

Get all namespaces in the cluster

kubectl get namespaces
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This command lists all namespaces present in the cluster.

Get Pods from a specific namespace

kubectl get pods -n <namespace-name>
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Displays all Pods running in the specified namespace.

Create a namespace

kubectl create ns <namespace-name>
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Creates a new namespace with the given name.

Create a Pod in the default namespace

kubectl run <pod-name> --image=<image-name>
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Creates a Pod using the specified image in the default namespace.

Create a Pod in a specific namespace

kubectl run <pod-name> --image=<image-name> -n <namespace-name>
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Creates a Pod using the specified image in the specified namespace.

Delete a Pod from a namespace

kubectl delete pod <pod-name> -n <namespace-name>
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Deletes the specified Pod from the given namespace.

Apply a YAML file

kubectl apply -f <file-name.yml>
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Creates or updates Kubernetes resources defined in the YAML file. This command is commonly used for declarative configuration.

Delete a namespace

kubectl delete namespace <namespace-name>
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Deletes the specified namespace and all resources inside it. This is a destructive operation and should be used carefully.

Key takeaways
Namespaces help organize and manage resources within a Kubernetes cluster, but they do not control where Pods run or provide isolation by themselves.
Understanding namespaces is important before moving on to:

  • Deployments
  • Services
  • RBAC
  • Resource quotas

What’s Next?

  • Next, I plan to explore:
  • Deployments vs Pods
  • How controllers manage Pods
  • Real-world namespace usage patterns

I’ll continue documenting my learning as I go.

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