test_evnetlet_no_dnspython fails to import glance.cmd

[Corey Bryant]

The following test is failing during ubuntu package builds for mitaka b3:

======================================================================
FAIL: glance.tests.unit.common.test_wsgi_ipv6.IPv6ServerTest.test_evnetlet_no_dnspython
glance.tests.unit.common.test_wsgi_ipv6.IPv6ServerTest.test_evnetlet_no_dnspython
----------------------------------------------------------------------
_StringException: Traceback (most recent call last):
  File "/<<PKGBUILDDIR>>/glance/tests/unit/common/test_wsgi_ipv6.py", line 61, in test_evnetlet_no_dnspython
    self.assertEqual(0, rc)
  File "/usr/lib/python2.7/dist-packages/testtools/testcase.py", line 350, in assertEqual
    self.assertThat(observed, matcher, message)
  File "/usr/lib/python2.7/dist-packages/testtools/testcase.py", line 435, in assertThat
    raise mismatch_error
testtools.matchers._impl.MismatchError: 0 != 1

The mismatch error results when the import of glance.cmd fails and an ImportError is raised. If I comment out the following line, then the import of glance.cmd is successful but I'm not sure why:

os.environ['EVENTLET_NO_GREENDNS'] = '%s'

[Nikhil Komawar (nikhil-komawar)]

HI Corey,

I tried this on a ubuntu and it worked just fine. May I ask for the following info on this:

1. Does the system use IPv6 ?
2. Which environment does this fail on python27 or python 34 or both?
3. Do you have dnspython installed ?

The commit bd2a8422d3e8c975d023982c038a59ca0257c6dd is adding these tests is addressing issue for systems that have dnspython installed and have IPv6.

[Corey Bryant (corey.bryant)]

Hi Nikhil,

Thanks for taking a look. I have to figure it's a dependency issue where perhaps running from pip installed packages is getting different version than debian packages, which are at least at the min versions specified in global requirements.

> 1. Does the system use IPv6 ?

Yes, and the tests used to work.

> 2. Which environment does this fail on python27 or python 34 or both?

We're only running py27 right now.

> 3. Do you have dnspython installed ?

No

[Cyril Roelandt (cyril-roelandt)]

I cannot reproduce this bug either. I love how reproducible and isolated our tests are!

Could you re-raise the import error instead of calling sys.exit(), so that we have more details?