Kubernetes Namespaces

After reading this post you will be understanding the high level of Kubernetes namespace and basic kubectl commands related to namespaces.

What is namespace 🤔

In Kubernetes, namespaces provide a mechanism for isolating groups of resources within a single cluster. Names of resources need to be unique within a namespace, but not across namespaces.

Whenever you create a Kubernetes object without specifying a namespace, the object is placed in the Default namespace.

When you set up the cluster for the first time, Kubernetes will deploy the pod & services for the internal management these pods are created under the Kube-system namespaces by default. The purpose of the isolate is to prevent you from accidentally deleting or modifying these services.

kube-node-lease This namespace holds Lease objects associated with each node. Node leases allow the kubelet to send heartbeats so that the control plane can detect node failure.

kube-public this is another default namespace in the Kubernetes,

Kube-system output

coredns-6d4b75cb6d-2vqw4                   1/1     Running   1 (6d2h ago)   10d
coredns-6d4b75cb6d-9dlh8                   1/1     Running   1 (6d2h ago)   10d
etcd-kubernet-master                       1/1     Running   1 (6d2h ago)   10d
kube-apiserver-kubernet-master             1/1     Running   1 (6d2h ago)   10d
kube-controller-manager-kubernet-master    1/1     Running   1 (6d2h ago)   10d
kube-proxy-6drkc                           1/1     Running   1 (6d2h ago)   10d
kube-proxy-c5jr7                           1/1     Running   1 (6d2h ago)   10d
kube-scheduler-kubernet-master             1/1     Running   1 (6d2h ago)   10d

👌Namespace you can short to ns

If your environment is small you shouldn’t really have to worry about namespaces, you could continue to work in the default namespace.

Viewing the current namespace

kubectl get namespace

Default output

NAME              STATUS   AGE
default           Active   1d
kube-node-lease   Active   1d
kube-public       Active   1d
kube-system       Active   1d

How to create namespace through manifest file

apiVersion: v1
kind: Namespace
metadata:
  name: test
  labels:
    name: test
kubectl apply -f test.yaml

Create Namespace through CLI

kubectl create namespace test

How to create the container inside the namespace

kubectl run nginx -n test --image=nginx

apiVersion: v1
kind: Pod
metadata:
  name: mypod
  namespace: test
  labels:
    name: mypod
spec:
  containers:
  - name: mypod
    image: nginx

If you try to find your Pod, you might notice you can’t!

This is because all commands are run against the currently active Namespace. To find your Pod, you need to use the “namespace” flag.

kubectl get pods --namespace=test
or 
kubectl get pod -n test

How to delete the namespace

kubectl delete namespace test

What happens if I delete a namespace?

Deleting the namespace also deletes all the residing components. However, removing all deployments within a namespace does not remove the namespace.

Namespace overview

Refer to this link for more understanding about Namespaces 👉Name sapces

Do you know how to create the Pod? 🤔

Don't worry please refer to this link 👉 Pod Creation

Hope you have got an idea about Kubernetes Namespaces and how we can implement them in our product environments

Happy Learning !!!

Thank you!

Kubernetes Namespaces

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