Namespaces isolates pods to separate workloads from each other and it gives you the capability of setting up resource constrainsts on it. It could fit with environment segregation.
Discover Kubernetes namespaces
Let's take a look at the initial Kubernetes namespaces:
kubectl get namespace
By default, Kubernetes comes with three namespaces. We can see them here:
This namespace has objects created by Kubernetes system:
kubectl get pods -n kube-system; echo
Pods inside of this namespace are needed to make Kubernetes works, such as controllers and add-ons natively integrated with Kubernetes which we will talk later on
Note: Usually each cloud provider will run specific implementation pods in this namespace too - so don't worry if the
kube-systemnamespace differs between clusters/cloud providers.
This namespace just contains a configmap which has the bootstrapping and certificate information of the K8s cluster:
kubectl get pods -n kube-public; echo
You don't see anything running in this namespace but we can see a
kubectl get configmap -n kube-public cluster-info -o yaml; echo
In addtion, this namespace might be treated as a namespace to run any object which should be visible and readable throughout the whole cluster since it is visible and readable from all parts of the Kubernetes cluster.
All objects created without specifying a namespace will automatically be created in the
This namespace is empty and doesn't contain any objects:
kubectl get pods -n default; echo
One thing to note about the
default namespace is that it can't be deleted, unlike other namespaces within the Kubernetes cluster.