Kubernetes namespaces

Kubernetes starts with four initial namespaces:

• default is the default namespace for objects with no other namespace.
• kube-system for objects created by the Kubernetes system.
• kube-public 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-node-lease holds lease objects associated with each node. Node leases allow the kubelet to send heartbeats so that the control plane can detect node failure.

Additional documentation: https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/ Other typical namespaces: monitoring, cluster-autoscaler

Commands

• kubectl get namespaces

kubectl create namespace MY_TEST_NAMESPACE 
namespace/MY_TEST_NAMESPACE created

• kubectl create namespace argocd

• kubectl describe namespace

• kubectl get all --all-namespaces
• kubectl get pods --all-namespaces

Activities

• CKA: Create and configure basic Pods: kubectl create, kubectl apply

Related terms

• kind: namespace
• helm list
• helm install -n, --namespace
• No resources found in default namespace.
• kubectl get configmaps -A
• default, kube-node-lease, kube-public, kube-system
• Namespace controller

EKS

• logging
• aws-load-balancer-controller Ingress controller

See also

• kubectl: [ cp | config | create | delete | edit | explain | apply | exec | get | set | drain | uncordon | rolling-update | rollout | logs | run | auth | label | annotate | version | top | diff | debug | replace | describe | port-forward | proxy | scale | rollout | api-resources | expose deployment | expose | patch | attach | get endpoints | ~/.kube/config | kubectl logs --help | kubectl --help, kubectl-convert, kubectl autoscale, kubectl.kubernetes.io
• Kubernetes namespaces: kubectl get namespaces, kube-system namespace, --namespace

https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/