Share a Cluster with Namespaces [page]deterministic

tasks

This page shows how to view, work in, and delete [namespaces](#gloss:namespace). The page also shows how to use Kubernetes namespaces to subdivide your cluster.

* Have an [existing Kubernetes cluster](/docs/setup/). * You have a basic understanding of Kubernetes [Pods](#gloss:pod), [Services](#gloss:service), and [Deployments](#gloss:deployment).

## Viewing namespaces

List the current namespaces in a cluster using:

```shell kubectl get namespaces ``` ```console NAME STATUS AGE default Active 11d kube-node-lease Active 11d kube-public Active 11d kube-system Active 11d ```

Kubernetes starts with four initial namespaces:

* `default` The default namespace for objects with no other namespace * `kube-node-lease` This namespace holds [Lease](/docs/concepts/architecture/leases/) objects associated with each node. Node leases allow the kubelet to send [heartbeats](/docs/concepts/architecture/nodes/#heartbeats) so that the control plane can detect node failure. * `kube-public` This namespace is created automatically and is readable by all users (including those not authenticated). This namespace is mostly reserved for cluster usage, in case that some resources should be visible and readable publicly throughout the whole cluster. The public aspect of this namespace is only a convention, not a requirement. * `kube-system` The namespace for objects created by the Kubernetes system

You can also get the summary of a specific namespace using:

```shell kubectl get namespaces <name> ```

Or you can get detailed information with:

```shell kubectl describe namespaces <name> ``` ```console Name: default Labels: <none> Annotations: <none> Status: Active

No resource quota.

Resource Limits Type Resource Min Max Default ---- -------- --- --- --- Container cpu - - 100m ```

Note that these details show both resource quota (if present) as well as resource limit ranges.

Resource quota tracks aggregate usage of resources in the Namespace and allows cluster operators to define *Hard* resource usage limits that a Namespace may consume.

A limit range defines min/max constraints on the amount of resources a single entity can consume in a Namespace.

See [Admission control: Limit Range](https://git.k8s.io/design-proposals-archive/resource-management/admission_control_limit_range.md)

A namespace can be in one of two phases:

* `Active` the namespace is in use * `Terminating` the namespace is being deleted, and can not be used for new objects

For more details, see [Namespace](/docs/reference/kubernetes-api/cluster-resources/namespace-v1/) in the API reference.

## Creating a new namespace

> Note: Avoid creating namespace with prefix `kube-`, since it is reserved for Kubernetes system namespaces.

Create a new YAML file called `my-namespace.yaml` with the contents:

```yaml apiVersion: v1 kind: Namespace metadata: name: <insert-namespace-name-here> ``` Then run:

```shell kubectl create -f ./my-namespace.yaml ```

Alternatively, you can create namespace using below command:

```shell kubectl create namespace <insert-namespace-name-here> ```

The name of your namespace must be a valid [DNS label](/docs/concepts/overview/working-with-objects/names#dns-label-names).

There's an optional field `finalizers`, which allows observables to purge resources whenever the namespace is deleted. Keep in mind that if you specify a nonexistent finalizer, the namespace will be created but will get stuck in the `Terminating` state if the user tries to delete it.

More information on `finalizers` can be found in the namespace [design doc](https://git.k8s.io/design-proposals-archive/architecture/namespaces.md#finalizers).

## Deleting a namespace

Delete a namespace with

```shell kubectl delete namespaces <insert-some-namespace-name> ```

> Warning: This deletes _everything_ under the namespace!

This delete is …(trimmed)