[feature request] add --feature-gate flag to yurt-controller-manager

[DrmagicE]

Context
Hi, I deployed openyurt on a cluster with 2 nodes(1 master and 1 worker) to test the autonomy behaviour.
After setting-up yurt-controller-manager and yurt-hub, I stop the kubelet on the edge side.
The logs form yurt-controller-manager shows that the master is entering disruption mode, which is used to protect against master machine network isolation. It will prevent any evictions from happening if master can't see any healthy Node.

I0131 09:49:50.770911       1 node_lifecycle_controller.go:1230] Controller detected that all Nodes are not-Ready. Entering master disruption mode.

This is because my node name is ending with "master" and the lifecycle-controller will not take such node as a worker node:
https://github.com/alibaba/openyurt/blob/288aee566107ce7824669c59bb0b286074528293/pkg/controller/nodelifecycle/node_lifecycle_controller.go#L1004-L1015
I can disable LegacyNodeRoleBehavior by adding feature-gates flags to kube-controller-manager.

feature-gates: https://kubernetes.io/docs/reference/command-line-tools-reference/feature-gates/

...
spec:
  containers:
  - command:
    - kube-controller-manager
    - --allocate-node-cidrs=true
    - --feature-gates=LegacyNodeRoleBehavior=false <-- adding this line 
...

But the openyurt seems does not has such flag:

...
unknown flag: --feature-gates

What would you like to be added:
Add --feature-gates flag to yurt-controller-manager.

Why is this needed:
There should be a way to configure feature gates.

[rambohe-ch]

@DrmagicE Thank you for filing issue to discuss --feature-gates.
I think that add --feature-gates for yurt-controller-manager is a good idea.
how about you? @Fei-Guo @kadisi

[Fei-Guo]

It sounds reasonable to me.

[rambohe-ch]

@DrmagicE It looks like that you had dived into the implementation, would you take over this feature that add --feature-gates for yurt-controller-manager?

[DrmagicE]

@rambohe-ch No problems. I will give it a try.