fix(eventbus): set nats routes with pod DNS names. Fixes #1026

[whynowy]

Signed-off-by: Derek Wang whynowy@gmail.com

Checklist:

• My organization is added to USERS.md.

Fixes #1026

Old config:

http: 8222
include ./auth.conf
cluster {
  port: 6222
  routes [
   nats://eventbus-default-stan-svc:6222
  ]
  cluster_advertise: $CLUSTER_ADVERTISE
  connect_retries: 10
}
streaming {
  xxxxxx
}

New config:

http: 8222
include ./auth.conf
cluster {
  port: 6222
  routes: [
   nats://eventbus-default-stan-0.eventbus-default-stan-svc.argo-events.svc:6222,nats://eventbus-default-stan-1.eventbus-default-stan-svc.argo-events.svc:6222,nats://eventbus-default-stan-2.eventbus-default-stan-svc.argo-events.svc:6222
  ]
  cluster_advertise: $CLUSTER_ADVERTISE
  connect_retries: 10
}
streaming {
  xxxxx
}

Tested in a real environment, routes change in the configmap will be gradually picked up when the NATS pods restart, and there's no impact even when mixed old and new config are used by different replicas.

[alexec]

note that my reviews assume that you understand the topic, and you've written the requisite tests - I don't do QA on PRs for people