merge manually specified tub location with autodetected tub location

[zooko]

I'm configuring a laptop which is behind a home NAT to have a specified tub.location which says the IP address of my home network. (As described in docs/configuration.rst​.)

However, sometimes I take this laptop to other networks, and it would be nice if it would do the process of auto-detecting its current IP address and advertise both that and the manually-configured IP address that I am putting in, so that if clients can connect to it either way then they win.

[warner]

maybe we could use a magic value, like tub.location = auto+1.2.3.4:1234, which is interpreted to mean "merge 1.2.3.4:1234 with the auto-detected location".

[robk]

I pretty much just asked this question of zooko (he was online at the time)

in part it was because I hadn't found the docs/configuration.txt file - because I naturally go looking for info on the web, hence trac, hence had to go digging to find config instructions. (but that's another matter)

tub.location="some manually crafted stuff" handles the case I'm facing.

but "auto+some_manual_cruft" would be nice.

sign me up for a minor-priority vote in favour ;-)

[warner]

maybe tub.location = AUTO,1.2.3.4:1234 since Tub locations are supposed to be comma-separated anyways, and "AUTO" doesn't parse as a valid location (no colon).

robk: maybe we should have a Trac page that points at source:docs/configuration.txt ? Or, we've kicked around the idea of automatically copying the files in docs/ into wiki pages (since most of them use wikiformatting anyways), so maybe it should point at something like docs/configuration.txt? instead.

[zooko]

If you like this ticket, you may also like #49 (UPnP), #59 (STUNT/ICE), #169 (tcp hole-punching!), #445 (implement relay: allow storage servers behind NAT).

[zooko]

Oops that should be #50 (STUNT/ICE).

[daira]

chatcannon filed a pull request: ​https://github.com/tahoe-lafs/tahoe-lafs/pull/139

[daira]

The implementation in ​https://github.com/tahoe-lafs/tahoe-lafs/pull/139 looks good. To test it, look at TestCase.test_location2 at src/allmydata/test/test_node.py#L55​ and add a similar test_location_auto -- it should be easy to adapt.

[daira]

Re-review needed for ​https://github.com/tahoe-lafs/tahoe-lafs/pull/142.

[daira]

Fixed in [2d9af506f1d315016d0d63d6a7491ecd2a370448/trunk].

[daira]

Thanks chatcannon!

[daira]

Note that as an intended side-effect of this fix, setting tub.location without including "AUTO" will skip the local IP auto-detection code entirely, thus allowing a workaround for any platform- or system-specific problems with that code.