remove support for v1 introducer

[warner]

In Tahoe-LAFS-1.10.0 (May 2013), we created a new Introducer protocol which allows nodes to publish signed, extensible, dictionary-based announcements. Servers are known by their Ed25519 verifying key, rather than their Foolscap TubID (a hash of a TLS certificate).

To avoid a grid-wide "flag day", all three moving pieces (the sending client, the Introducer, and the receiving client) smoothly tolerate old-style "v1" messages, and peers which don't know how to speak the v2 protocol. New clients who discover they're talking to an old Introducer will send v1 messages instead of v2. New introducers who receive v1 messages from old clients will deliver them as unsigned v2 messages to new clients, and as v1 messages to old clients.

Now that 1.10.1 has been available for three years, it's time to remove support for the v1 protocol. This will delete maybe 30% of the code from src/allmydata/introducer/. Clients will unconditionally send and expect v2 messages, and the Introducer will only enable v2-capable clients to connect and subscribe to hear announcements.

[daira]

I'm fine with making this change for 1.12.0.

[Brian Warner <warner@…>]

In 155ca03/trunk:

test_introducer: cleanups

• Use tempfile for cache to avoid collisions
• Fix pyflakes complaints
• Remove test_client_cache_2, which exercises unsigned announcements. These are scheduled to be removed soon (see ticket:2784) and don't need to be tested.

[dawuud]

I removed the old v1 introducer and and attempted to fix the test_introducer tests. I managed to fix all but one test; here in my dev branch

​https://github.com/david415/tahoe-lafs/tree/2784.remove_v1_introducer.0

​https://github.com/tahoe-lafs/tahoe-lafs/pull/289/files

this test fails allmydata.test.test_introducer.SystemTest.test_system_v2_server

[dawuud]

After much butchering of the tests the SystemTest? now passes... but this definitely needs review ;-p

[warner]

Thanks for diving into this. I made a start at it a few weeks ago, but got stuck too early to be worth pushing anywhere. I'll see if I can review/build-upon your branch.

[warner]

moving most tickets from 1.12 to 1.13 so we can release 1.12 with magic-folders

[Brian Warner <warner@…>]

In c64ff7b/trunk:

more v1 removal cleanup

Historical note: V2 introducers have been around for three years
now (released in 1.10.0), so it's time to drop v1. This branch removes a
lot of fallback code, and tests which exercised it. refs ticket:2784

This patch removes some now-unused code: v1-related support functions on
the client, "stub-client" handlers, and v1-tolerant remote methods on
the server. The unit tests have been cleaned up a bit too, now that
there are fewer cases to exercise.

[Brian Warner <warner@…>]

In 78810d5/trunk:

Merge branch '2784-remove-v1-introducer'

Closes PR #289
Closes ticket:2784