I have followed the steps here and now have a functioning Swarm:
I exposed port 8080 on the swarm but the Admin UI is not functional. The browser logs are filled with this sort of error:
oconnection error: desc = "transport: x509: certificate is valid for cockroachdb-1, localhost, not 8615fec8cdc4"
In the swarm, ‘cockroachdb-1’ is the host name that returns the virtual IP for the service. ‘8615fec8cdc4’ is the hostname for the container where the one instance of the service is running.