[feature request]can not move node to another nodepool by label modification

[rambohe-ch]

What would you like to be added:
the nodepool label of node can not be updated after node creation, this means we can not move a node into another nodepool by changing node label simply.

if end users want to move a node to another nodepool, they should drain all pods on the node at first, and then delete and reset this node from cluster, and re-join this node into the cluster.

so we will add a webhook in yurt-manager to prevent updating nodepool label of node.

Why is this needed:
Because the NodePool is the first class citizen in OpenYurt, and node must belong to a NodePool and only one NodePool, it is not secure to move a node into another NodePool by label changing.

others
/kind feature

[y-ykcir]

@rambohe-ch I want to try this, does this mean adding a validation webhook for node updates?

[rambohe-ch]

@rambohe-ch I want to try this, does this mean adding a validation webhook for node updates?

@y-ykcir yes, we need to add a validate webhook to handle this. maybe we need to discuss this feature on community meeting because this feature will bring some changes to end users.

[rambohe-ch]

@y-ykcir by the way, we also need to prevent nodepool to be deleted if there are nodes in the nodepool.

[rambohe-ch]

@y-ykcir Do you have any time to work on this issue: #1080 in this week? @YTGhost is a little busy on other works.

[y-ykcir]

@y-ykcir Do you have any time to work on this issue: #1080 in this week? @YTGhost is a little busy on other works.

OK, I'll take a look.

[rambohe-ch]

@y-ykcir welcome you to apply OpenYurt community member, and you can take me as sponsor.

you can make a apply issue in openyurtio/community, and example looks like: openyurtio/community#62

[y-ykcir]

@y-ykcir welcome you to apply OpenYurt community member, and you can take me as sponsor.

you can make a apply issue in openyurtio/community, and example looks like: openyurtio/community#62

Thx a lot! I'll apply after tackling the issue #1080