WIP: Add minikube support for the "generic" VM driver

[afbjorklund]

This driver connects to an already existing virtual machine,
using the provided IP address and SSH user/key/port parameters.

On this machine, libmachine will provision the docker daemon
and minikube will bootstrap the kubernetes cluster (as usual).

Implements #4733

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: afbjorklund

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [afbjorklund]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[medyagh]

could you provide an example with the PR so we have a context ?

[medyagh]

I am thinking if we could use this in the VM-free model too, maybe if the generic driver supports exec-ing into a docker container ?

[afbjorklund]

I am thinking if we could use this in the VM-free model too, maybe if the generic driver supports exec-ing into a docker container ?

The generic driver is quite specific about wanting something to ssh into, but you could of course start a sshd in your "node" container ?

https://github.com/docker/machine/blob/master/drivers/generic/generic.go

[afbjorklund]

Typical, seems like the generic install (https://get.docker.com) is more strict about security...

If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:

  sudo usermod -aG docker vagrant

Remember that you will have to log out and back in for this to take effect!

WARNING: Adding a user to the "docker" group will grant the ability to run
         containers which can be used to obtain root privileges on the
         docker host.
         Refer to https://docs.docker.com/engine/security/security/#docker-daemon-attack-surface
         for more information.

That doesn't really work, since minikube normally assumes that user has group access:

Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.39/version: dial unix /var/run/docker.sock: connect: permission denied

[afbjorklund]

Added the user to the group, but doesn't work with vagrant since it only uses one IP (i.e. 127.0.0.1)

The connection to the server 127.0.0.1:8443 was refused - did you specify the right host or port?

[afbjorklund]

I think I will split this PR

[afbjorklund]

This PR is not going to be merged (it keeps on breaking!), so mostly using it for testing...

[k8s-ci-robot]

@afbjorklund: PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.