Just curious about the intent for this default namespace.
Thanks in advance.
To complete the previous answer, these are the objects inside the namespace kube-public
:
$ kubectl get_all --namespace kube-public
NAME NAMESPACE
secret/default-token-jd2k2 kube-public
serviceaccount/default kube-public
rolebinding.rbac.authorization.k8s.io/system:controller:bootstrap-signer kube-public
role.rbac.authorization.k8s.io/system:controller:bootstrap-signer kube-public
That namespace exists in clusters created with kubeadm for now. It contains a single ConfigMap object, cluster-info, that aids discovery and security bootstrap (basically, contains the CA for the cluster and such). This object is readable without authentication.
If you are courious:
$ kubectl get configmap -n kube-public cluster-info -o yaml
There are more details in this blog post and the design document:
NEW: kube-public namespace
[...] To create a config map that everyone can see, we introduce a new kube-public namespace. This namespace, by convention, is readable by all users (including those not authenticated). [...]
In the initial implementation the kube-public namespace (and the cluster-info config map) will be created by kubeadm. That means that these won't exist for clusters that aren't bootstrapped with kubeadm. [...]