Make VirtualBox network configurable

[bfirsh]

At the moment the subnet used by VirtualBox is hard coded. It would be neat if this was configurable, like in boot2docker-cli.

[sthulb]

Given this is specific to the virtualbox driver, I guess an argument on the driver would make the most sense.

[andyshinn]

Along the lines of network configuration, would port forwarding fall under this issue?

I currently use Vagrant to bring up Docker hosts on OS X as it can do port forwarding, which helps transition from local development to Docker development. Usually in local development you hit your services at localhost:3000. Port forwarding on your Docker host helps keep this same pattern and known location.

[sthulb]

I'm not sure if machine could offer port forwarding like that... unless you knew exactly which services you wanted to run before creating a machine

[ehazlett]

I think we could do port forwarding but perhaps this is an area for a plugin? Machine already gives the host only network to avoid the port forwarding issues. Maybe a plugin would be able to expose it?

[cwilkes]

I would like to see this as our company's Cisco VPN client sets up firewall rules which don't know about vboxnetN adapters and thus connections to 192.168.* address are blocked.
However lo* adapter traffic is allowed so if I could get the DOCKER_HOST set to an ip in the 127.0.0.* range then I could easily use machine-docker instead of boot2docker.

[bergman]

👍 This is keeping me on boot2docker due to 192.168.99.x already used in my network.

[justinclayton]

+1. same issue as @cwilkes with Cisco AnyConnect VPN. Can't use docker-machine with the certs if I'm to use the workaround listed here: boot2docker/boot2docker#628