Namespace

Namespaces provide for a scope of Kubernetes objects. You can think of it as a workspace you’re sharing with other users. Many objects such as pods and services are namespaced, while some (like nodes) are not. As a developer you’d usually simply use an assigned namespace, however admins may wish to manage them, for example to set up access control or resource quotas.

To list all namespaces

kubectl get ns

You can learn more about a namespace using the describe verb, for example:

kubectl describe ns default

Let’s now create a new namespace called test now:

kubectl create -f https://raw.githubusercontent.com/mhausenblas/kbe/master/specs/ns/ns.yaml

kubectl get ns

To launch a pod in the newly created namespace test, do:

kubectl create --namespace=test -f https://raw.githubusercontent.com/mhausenblas/kbe/master/specs/ns/pod.yaml

Note that using above method the namespace becomes a runtime property, that is, you can easily deploy the same pod or service, or RC, etc. into multiple namespaces (for example: dev and prod). If you however prefer to hard-code the namespace, you can define it directly in the metadata like so:

apiVersion: v1

kind: Pod

metadata:

  name: podintest

  namespace: test

To list namespaced objects such as our pod podintest, run following command as:

kubectl get pods --namespace=test

You can remove the namespace (and everything inside) with:

kubectl delete ns test

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