Document setting up Vagrant-docker with the remote API

[ucarion]

Hi,

I was having trouble setting up the remote HTTP API on my machine and I previously opened an issue asking how to set this up. In this PR I document what @pyotr777 explained in #2280.

I absolutely had no idea where to document this other than to put it in contrib/vagrant as recommended by @shykes, so if I did this wrong I'll be happy to amend this PR.

Closes #2280

[tianon]

This LGTM, but I'd want @mzdaniel to take a look at it, because I'm not at all familiar with Vagrant. :)

[ucarion]

I've revised my PR as @donpinkster pointed out that I said a few things about Docker that weren't true in the general case.

I think that having people modify the Vagrantfile to have those SSH ports forwarded is not the easiest way to get things working, so I haven't mentioned that.

[ucarion]

Is this good to merge?

[pyotr777]

Thanks for summarizing it up.
As for me, I am not sure if it is correct to say about IP 127.0.0.1 concerning initial (default) Docker behavior. Reading the manual here (http://docs.docker.io/en/latest/api/docker_remote_api/) makes me think Docker uses a Unix Domain Socket which is not a network socket and is not associated with any particular IP address. But I could be wrong.

Except for that, the text looks good to me.

[ucarion]

@pyotr777 Seeing as I really don't understand where Docker is looking for things by default, I instead just removed that last part altogether. Thanks for the feedback.

[creack]

/cc @metalivedev @mzdaniel

[metalivedev]

Doesn't setting FORWARD_DOCKER_PORTS=1 work for you? I still see it in the Vagrantfile.

[vieux]

FORWARD_DOCKER_PORTS only redirects ports > 49000 (the ports generated randomly by docker)
My the solution woudb be to update the vagrantfile to add 4243 with FORWARD_DOCKER_PORTS ?

[crosbymichael]

@ulyssecarion Can you please rebase?

ping @mzdaniel

[ucarion]

@crosbymichael Does it look good now? There was a merge conflict, so I just appended my modifications to the stuff that was added since I made this PR.

[crosbymichael]

LGTM

ping @vieux I think we can merge this if it looks fine to you

[vieux]

LGTM I'll let @metalivedev decide

[crosbymichael]

@vieux it's in contrib