Open MC on the Mac, then go to File-->Library-->Library Manager. Once you've opened library manager, you should see an option to "add library." You can click that button and then enter the information from your docker instance in the popup. Now the Mac MC instance will be a client of the Docker instance. In order to be able to make changes on the Mac, though, you will need to make sure authentication is enabled on the Docker instance, and enter the username and password on the Mac client.