addDaemon
Adds a daemon to the list of available DockerDaemon for dispatch.
If a daemon with the same hostname is already registered to the dispatcher, the operation will block on the coroutine until all tasks on the original daemon has been completed, or the connection to the daemon has been lost.
Parameters
hostname
The hostname/URL of the new daemon to add.
isMainHost
true if the host does not exclusively house the Docker engine service.