Machine: Docker-machine add existing host

[ghost]

We need a way to add a machine running the Docker daemon to the docker-machine machine's list. At present it is very difficult/impossible to do this. This means that on older Mac's like mine that don't support the new Docker binary can't use docker unless you provision a new instance. It also means that deploying containers on instances that aren't running x86_64 kernels, such as Raspberry Pi, a huge pain.

I know that this has been covered before, however it this functionality is sorely needed and is heavily requested by the community.

[nathanleclaire]

--driver generic isn't fit for your use case?

[ghost]

No. docker-machine create --driver generic does several things, including changing the hostname to be that of the name given as argument $1. This, as well as restarting/upgrading/downgrading the daemon is less than desirable behavior on a host that has already been provisioned and has containers running on it.

[ralphie02]

Any plans in the future for such functionality to be implemented?? I'm investigating how I could use this method to link a Jenkins server into a docker host on a different server.

[gittycat]

Agreed. A docker-machine add command would greatly facilitate this task.

The best alternative I've seen right now is to use docker-machine create -d none but this means lots of finicky work to create/copy/manage the certs.
See https://www.boerngen-schmidt.de/2017/05/connect-to-a-remote-docker-host-with-docker-machine-using-tls-certificates/

[danmaz74]

Yes please! Not having this is a really big problem.

[rayjohnson]

I just ran into this as well. Was about to create a new bug - but I found this one.

From my perspective, I think what is needed is for the "none" driver to have some driver options to pass the keys and certs.

Something like:
--none-ca-cert=
--none-client-key=
--none-server-cert=

This would be way cleaner and easier than messing with the json directly. (Way easier to explain to others as well!)

[rayjohnson]

Also, sometimes when talking to an existing engine it is an older version of Docker. It would be nice if docker-machine could also specify and set DOCKER_API_VERSION.

Maybe add the option:
--none-api-version=1.23

Then docker-machine env would also spit out DOCKER_API_VERSION=1.23
(And maybe COMPOSE_API_VERSION as well.)

[smcardle]

Looking to see if there is any update or action regarding this issue.

I am currently trying to resolve the same thing.
I have multiple VM's running docker engine that I would like to manage as a swarm via docker-machine without renaming the current hosts and upgrading their docker engine api versions.