[Bug 1897969] Re: switch to importlib.metadata package has nullified verify_requirements argument

[Corey Bryant]

** Also affects: stevedore (Ubuntu)
   Importance: Undecided
       Status: New

-- 
You received this bug notification because you are a member of Ubuntu
OpenStack, which is subscribed to stevedore in Ubuntu.
https://bugs.launchpad.net/bugs/1897969

Title:
  switch to importlib.metadata package has nullified verify_requirements
  argument

Status in stevedore:
  New
Status in stevedore package in Ubuntu:
  New

Bug description:
  It seems that commit d5297167 'switch to importlib.metadata package'
  has changed the behavior of _load_one_plugin() by nullifying the
  verify_requirements argument:

  -            plugin = ep.load(require=verify_requirements)
  +            plugin = ep.load()

  In the scenario I'm looking at, stevedore is used by heat to load a
  number of client entry points (see list at
  https://opendev.org/openstack/heat/src/branch/stable/victoria/setup.cfg#L69).

  Prior to this change in stevedore, failure to load one of these entry
  points would result in a warning but not a hard failure. For example,
  if the vitrageclient module wasn't installed it would result in:

  2020-09-30 17:43:14.597 39486 WARNING heat.common.pluginutils [-]
  Encountered exception while loading heat.engine.clients.os.vitrage:
  "No module named 'vitrageclient'". Not using vitrage.:
  ModuleNotFoundError: No module named 'vitrageclient'

  However with commit d5297167, the same load now fails hard (see
  formatted traceback in attachment below).

  
  If I revert stevedore/extension.py to the state at d5297167~1, the old warning behavior is restored.

To manage notifications about this bug go to:
https://bugs.launchpad.net/python-stevedore/+bug/1897969/+subscriptions