Namespaces

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. Namespace-based scoping is applicable only for namespaced objects (e.g. Deployments, Services, etc.) and not for cluster-wide objects (e.g. StorageClass, Nodes, PersistentVolumes, etc.).

Default Namespaces

Creates four default namespaces

• default

• kube-node-lease

• kube-public

• kube-system

to manage cluster resources

kubectl get ns 
NAME              STATUS   AGE
default           Active   30m
kube-node-lease   Active   30m
kube-public       Active   30m
kube-system       Active   30m

Create a namespace

kubectl create namespace testing

Output:

kubectl create namespace testing
namespace/testing created

kubectl get namespace
NAME              STATUS   AGE
default           Active   31m
kube-node-lease   Active   31m
kube-public       Active   31m
kube-system       Active   31m
testing           Active   12s

Namespace YAML Template

cat <<EOF > namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: testing
EOF