I have an existing Docker swarm consisting of three machines. I am trying to add a new manager to this swarm. I run the command
docker swarm join --token SWMTKN-1-<...> 192.168.200.200:2377
After a while I get the error
Error response from daemon: manager stopped: can't initialize raft node: rpc error: code = Unknown desc = could not connect to prospective new cluster member using its advertised address: rpc error: code = DeadlineExceeded desc = context deadline exceeded
I view the daemon logs using tail -f /var/log/messages | grep docker, I see this:
Mar 17 17:07:48 UAT-Blockchain dockerd: time="2021-03-17T17:07:48.575024542+08:00" level=warning msg="grpc: addrConn.createTransport failed to connect to {/var/run/docker/swarm/control.sock <nil> 0 <nil>}. Err :connection error: desc= \"transport: Error while dialing dial unix /var/run/docker/swarm/control.sock: connect: no such file or directory\". Reconnecting..." module=grpc
A quick check shows that /var/run/docker/swarm/control.sock is indeed missing on this machine, but is present on the machines in the existing swarm.
What is this control.sock? How should I go about enabling/reinstating it on this current machine? Is this a problem of faulty installation?