Kubernetes Namespace

Namespaces are used to logically segregate objects in the cluster
Namespaces allows to define quotes which can be used to ensure that all namespaces have enough resources

kubectl get namespaces

Four namespaces created by default:

• kube-system: Consist of K8s management process. Should not be accessed by user
• kube-public: Contains config map which has cluster information that can be accessed even without authentication
• kube-node-lease: Contains hearthbeat information. Each node as associated lease object in namespace. Determines availability of Nodes
• default: User resources without namespaces are created here

kubectl create namespace <namespace-name>

Important

• Most resources cannot be access from another Namespace (ConfigMap, Secret)
• Service can be accessed from another namespace (<service-name>.<namespace-name>)
• Volumes and Nodes cannot be added into a namespace (They are global resources)

# Resource that cannot be namespaced
kubectl api-resources --namespaced=false

An object can be created in a specific namespace by specifying the name in the YAML file in the metadata session or using the -n flag on the terminal