change: use DERP port from host_name URL

[Frando]

Now that DerpNode::host_name is an URL, the DERP port can be part of that URL, so we don't need a separate derp_port field anymore.

This makes setting custom DERP config or accepting a DERP server from the command line much simpler, because you need only a single URL string and not multiple options.

It looks a bit weird in the test code because oftenly those use http://derp.invalid:{port} now. I think we could just put the full IP in the address also and not set UseIpv4::Some().

[dignifiedquire]

yesss, much better

[dignifiedquire]

looks like some tests are failing though

[Frando]

The remaining fail is in netsim - never worked with those, how do I debug this?

[Arqu]

So looking at both, netsim has a derpmap provided. Unsure where the issue comes from, but in the logs, seems like both the server and client fail handshakes (presumably with the derper). My assumption here is that now that the derp_port is obsolete it tries to do just http but some port got misplaced and now it fails to establish a connection.

Note that the test that is failing is where the provide side is behind a NAT, so some confusion might be happening due to the setup. @dignifiedquire already dealt with a similar bug before.

TLDR; either it's a config issue and you might be able to help me understand where and I can update netsim or we re-introduced a bug we closed in #1128

[Frando]

Ah, so the netsim config would need to change to this with/after this PR:
n0-computer/chuck@main...Frando:chuck:patch-1

How are changes between chunk and iroh synchronized currently?

[Frando]

Something else: Now that host_name is a URL with optional port, host_name is not really the fitting term anymore, is it? Maybe we should change it to derp_url or derp_server or something similar right away?

[dignifiedquire]

host_name is not really the fitting term anymore

Maybe just host or url?

[dignifiedquire]

merge conflict

[Frando]

Rebased and changed the field name to url.

I was undecided about naming the field host vs url because neither is fully correct, but URL seemed "more correct" as we support 3 parts of a typical URL (scheme, host, port) and just not any path parts, but more than just a hostname. But can ofc change again if something else is deemed better.

[Arqu]

I'm happy with where it's at. Once approved, we just need to bump the netsim derp map config too.