Enables support for running kubelet in a user namespace.
The user namespace has to be created before running kubelet.
All the node components such as CRI need to be running in the same user namespace.
- Tracking issue: kubernetes/enhancements issue 2033
- KEP: https://github.com/kubernetes/enhancements/tree/master/keps/sig-node/2033-kubelet-in-userns-aka-rootless
- Implementation: kubernetes/kubernetes PR 92863
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>