I'm having a strange issue with docker-machine create, I create a machine using 'docker-machine create --driver generic' command on a gcp instance and I can verify its creation using the 'docker-machine ls' command which shows running but after few seconds it gets disconnected and shows timeout in same command. Even my ssh connection to the target gets lost, no telnet to port 22. Seems to be a networking issue.
Output to 'docker-machine --debug ls' command
Docker Machine Version: 0.14.0, build 89b8332
Found binary path at /usr/local/bin/docker-machine
Launching plugin server for driver generic
Plugin server listening at address 127.0.0.1:42913
() Calling .GetVersion
Using API Version 1
() Calling .SetConfigRaw
() Calling .GetMachineName
timeout set to 10s
(gcp1-amar) Calling .GetURL
(gcp1-amar) Calling .DriverName
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
gcp1-amar generic Timeout
Making call to close driver server
(gcp1-amar) Calling .Close
(gcp1-amar) DBG | Closing plugin on server side
Successfully made call to close driver server
Making call to close connection to plugin binary
It was due to sshguard blacklisting my docker machine IP on all docker instances, I don't know why. But I finally solved it by removing all the sshguard chains from my firewalls.