Kubernetes also has an additional construct for isolation at the cluster level. In most cases, you can run Kubernetes and never worry about namespaces; everything will run in the default namespace if not specified. However, in cases where you run multitenancy communities or want broad-scale segregation and isolation of the cluster resources, namespaces can be used to this end. True, end-to-end multitenancy is not yet feature complete in Kubernetes, but you can get very close using RBAC, container permissions, ingress rules, and clear network policing. If you're interested in enterprise-strength multitenancy right now, Red Hat's Openshift Origin (OO) would be a good place to learn.
To start, Kubernetes has two namespaces—default and kube-system. The kube-system namespace is...
