Revert "Disable eventlet monkey-patching of DNS"

This reverts commit 6219f94b3a.

This commit seems to cause keystone auth to hang when using
Keystone w/ Swift.

Fixes LP Bug #1178646.

Change-Id: Ieb94a29b3129847c84a02c8a526611f125f21ea0

bin/keystone-all

@@ -2,25 +2,12 @@
 # vim: tabstop=4 shiftwidth=4 softtabstop=4
 
 import greenlet
+import eventlet
 import logging
 import os
 import signal
 import sys
 
-# NOTE(mikal): All of this is because if dnspython is present in your
-# environment then eventlet monkeypatches socket.getaddrinfo() with an
-# implementation which doesn't work for IPv6. What we're checking here is
-# that the magic environment variable was set when the import happened.
-if ('eventlet' in sys.modules and
-        os.environ.get('EVENTLET_NO_GREENDNS', '').lower() != 'yes'):
-    raise ImportError('eventlet imported before keystone-all '
-                      '(env var set to %s)'
-                      % os.environ.get('EVENTLET_NO_GREENDNS'))
-
-os.environ['EVENTLET_NO_GREENDNS'] = 'yes'
-
-import eventlet
-
 # If ../keystone/__init__.py exists, add ../ to Python search path, so that
 # it will override what happens to be installed in /usr/(local/)lib/python...
 possible_topdir = os.path.normpath(os.path.join(os.path.abspath(__file__),

keystone/__init__.py

@@ -1,15 +0,0 @@
-
-import os
-import sys
-
-# NOTE(mikal): All of this is because if dnspython is present in your
-# environment then eventlet monkeypatches socket.getaddrinfo() with an
-# implementation which doesn't work for IPv6. What we're checking here is
-# that the magic environment variable was set when the import happened.
-if ('eventlet' in sys.modules and os.environ.get(
-        'EVENTLET_NO_GREENDNS', '').lower() != 'yes'):
-    raise ImportError('eventlet imported before keystone '
-                      '(env var set to %s)'
-                      % os.environ.get('EVENTLET_NO_GREENDNS'))
-
-os.environ['EVENTLET_NO_GREENDNS'] = 'yes'

keystone/test.py

@@ -14,14 +14,12 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-
-import os
-import sys
-
 import datetime
 import errno
+import os
 import socket
 import subprocess
+import sys
 import time
 
 import eventlet
@@ -353,6 +351,10 @@ class TestCase(NoModule, unittest.TestCase):
     @staticmethod
     def skip_if_no_ipv6():
 
+        # TODO(blk-u): lp 1176204. At this time, eventlet address resolution
+        # doesn't support IPv6. Once it does, remove the next line.
+        raise nose.exc.SkipTest("Eventlet doesn't support IPv6, lp 1176204")
+
         try:
             s = socket.socket(socket.AF_INET6)
         except socket.error as e: