[Features]Node Topology awareness inside Database Application

[lancelot1989]

Some kind of databases have the ability to distribute data across different nodes according to the topology, like kafka’s broker.rack and replica.selector.class.

Currently, k8s's downward api cannot support node label(kubernetes/kubernetes#40610), so there is no official way to aware Node Topology inside Pod.

What if develop an api on kbagent to expose the Node Topology, and the startup scripts in addon can call this api and get Node Topology?

[shanshanying]

Hi @lancelot1989

As we discussed early this week, using KB-Agent to get Node Topology is not a good way (needs extra privileges and increates api-server burder). One alternative solutions in my mind is use postprovision action api mpd.spec.lifecycleActions.postProvision.