For HA and Quorum I will install three master / etc nodes in three different data centers.
But I want to configure one node to never become a leader. Only acts as follower for etcd quorum.
Is this possible?
I believe, today it is not a supported option and is not recommended.
what you want is to have 3 node control plane ( including etcd ) and one of the node should participate in leader election but not become leader and shouldnt store data. you are looking for some kind of ARBITER feature that exists in mongodb HA cluster.
ARBITER feature is not supported in ETCD. you might need to raise a PR to get that addressed.
The controller manager and scheduler always connect the local apiserver. You might want to route those calls to apiserver on the active master. You might need to open another PR for kubernetes community to get that addressed.