[tahoe-lafs-trac-stream] [Tahoe-LAFS] #3836: SystemTestMixin.set_up_grid configures an introducer that tries to automatically select a main tub port

[Tahoe-LAFS]

#3836: SystemTestMixin.set_up_grid configures an introducer that tries to
automatically select a main tub port
---------------------+---------------------------
 Reporter:  exarkun  |          Owner:  exarkun
     Type:  defect   |         Status:  new
 Priority:  normal   |      Milestone:  undecided
Component:  unknown  |        Version:  n/a
 Keywords:           |  Launchpad Bug:
---------------------+---------------------------
 `allmydata.test.common_system.SystemTestMixin._create_introducer` does not
 supply a configuration value for `tub.port` or `tub.location`.
 Consequently, the introducer created by this function tries to pick a free
 TCP port on its own to use for the main tub.  Since this process is
 subject to race conditions, this sometimes fails.  Since
 `_create_introducer` is called by `set_up_nodes` and `set_up_nodes` is
 essentially the whole point of `SystemTestMixin`, all test cases that use
 `SystemTestMixin` are subject to this intermittent failure condition.

 Instead, `_create_introducer` should supply a configuration that specifies
 a reliably available port for the main tub.

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3836>
Tahoe-LAFS <https://Tahoe-LAFS.org>
secure decentralized storage