need a section on port forwarding in instructions

[corporate-gadfly]

Instructions about port forwarding should be added.

Typical scenario:

Container Ports -> Docker Host Ports

dvm scenario:

Container Ports -> Docker Host Ports (on Virtualbox) -> Docker Client Ports (on OSX)

The Vagrantfile does not setup any forwarded ports.

So, if you are using dvm and you want to browse to a network port from your OSX browser (e.g., 8080), then unless a forwarded port is setup manually in Virtualbox or by the Vagrantfile (not done at the moment), the connection will be refused from OSX.

Another caveat is that ports < 1024 cannot be forwarded. You can get around it by using ipfw but I haven't looked into it.

[amaltson]

Indeed, dvm is really cool but without port forwarding I can't access any of the running docker images from OS X.

[drnic]

Perhaps it'd be nice to manage these via the dvm client. dvm add-port 5000 would update the internal Vagrantfile and run vagrant reload.

[amaltson]

:+1: to @drnic's idea, I like it.

[lalyos]

My workaround to access any port used by a container (even the ones not forwarded) is to use good old ssh as a socks proxy.

• You can ssh into docker and from docker you can ssh into the container.
• So you can set up ssh to do it in one step via proxy command. Now you can ssh directly to the container
• add a -D 1099 parameter to ssh, and you reach any ports of the container via ssh provided proxy listening on the port 1099

detailed description is here : http://lalyos.github.io/blog/2013/10/06/access-docker-containers-via-internal-ip/

[drewcrawford]

IMHO dvm should be assigned a private network address. That way all ports are reachable on the private network without having to manage any forwarding. Only 1 LOC.

[fnichol]

There isn't really a need for Vagrant port forwarding in this project, or at least that wasn't the initial goal. While boot2docker is kickass awesome, it currently forwards the Docker daemon port (TCP/4243) back to your localhost. In other words docker -h tcp://127.0.0.1:4243.

The driving need I had for something like dvm was for running infrastructure testing, like Test Kitchen using the kitchen-docker driver. For the driver to work we needed access to all the dynamically assigned ports, not just the Docker daemon port. That's why it uses a private network segment and address (192.168.42.43 by default). Once Docker supported the DOCKER_HOST environment variable, the actual IP address was less important and consequently makes the docker command on non-Linux distros feel almost native.

Additionally, I wanted something slightly more convenient than cd <some-vagrant-project-dir>; vagrant up every time I needed "dockers". dvm is a glorified shell wrapper around a slightly crazy Vagrantfile and passes most of its commands, magic, and awesome directly down to Vagrant.

Does that help clear up the confusion a little?

[fnichol]

Hopefully the commit above in the README helps to clarify things a bit better for future new users. Thanks all!

[stevepereira]

I think I'm missing something that could keep me from dvm - is there a possibility I could have a docker container port (for a webserver) available to my host mac @ localhost:8080 for instance using dvm? Do people do this with some other mechanism? Is 'export FORWARD_DOCKER_PORTS=1' related? I feel very noob asking, but I haven't been able to figure this out...