When peering through mesh gateways we expect outbound dials to peer
servers to flow through the local mesh gateway addresses.
Now when establishing a peering we get a list of dial addresses as a
ring buffer that includes local mesh gateway addresses if the local DC
is configured to peer through mesh gateways. The ring buffer includes
the mesh gateway addresses first, but also includes the remote server
addresses as a fallback.
This fallback is present because it's possible that direct egress from
the servers may be allowed. If not allowed then the leader will cycle
back to a mesh gateway address through the ring.
When attempting to dial the remote servers we retry up to a fixed
timeout. If using mesh gateways we also have an initial wait in
order to allow for the mesh gateways to configure themselves.
Note that if we encounter a permission denied error we do not retry
since that error indicates that the secret in the peering token is
invalid.
This commit adds handling so that the replication stream considers
whether the user intends to peer through mesh gateways.
The subscription will return server or mesh gateway addresses depending
on the mesh configuration setting. These watches can be updated at
runtime by modifying the mesh config entry.
freddygv