Integrate nat testing tool into ipfs daemon

[whyrusleeping]

I wrote a tool to help diagnose NAT setups: https://github.com/whyrusleeping/natest

I'm thinking we should look at integrating it into the ipfs daemon. A simple way would be to make an ipfs diag nat utility that runs the diagnostic, then advises the user on potential config changes they should make.

Slightly more interesting is doing this automatically (either on init, or on daemon startup) and automatically setting certain config options (as described here).

[overbool]

Hey @whyrusleeping , does this work need to continue? I found the compiling error undefined: swarm.NewNetwork in https://github.com/whyrusleeping/natest/blob/master/main.go. Maybe it should use new libp2p method.

[Stebalien]

It should.

[vyzo]

We are planning to integrate services for NAT autodetection: see #4993.

[vyzo]

Implementation WIP: libp2p/go-libp2p-autonat#1

[overbool]

@vyzo I'm interested in it, is there anything I can do to help?

[Stebalien]

Blocked on libp2p/go-libp2p#467. At the moment, there's no good way to access the NAT client from go-ipfs.

[momack2]

Checking in on this issue - is it still blocked?

[Stebalien]

We've worked around the issue with an event bus. We can (once we cut a libp2p release) listen for nat routability events.

I've filed #6951 to track printing this to stdout automatically.