Sync rpc from oslo.

Sync some trivial Python 3 compatibility and pep8 improvements from oslo.
I just want to have this in sync so that pulling in a feature I'm working
on comes in without unrelated changes

Change-Id: I13fcb0bd538a153b90acf0b18497e335a64dc9d1

nova/openstack/common/rpc/common.py

@@ -22,6 +22,7 @@ import sys
 import traceback
 
 from oslo.config import cfg
+import six
 
 from nova.openstack.common.gettextutils import _
 from nova.openstack.common import importutils
@@ -299,7 +300,8 @@ def serialize_remote_exception(failure_info, log_failure=True):
     tb = traceback.format_exception(*failure_info)
     failure = failure_info[1]
     if log_failure:
-        LOG.error(_("Returning exception %s to caller"), unicode(failure))
+        LOG.error(_("Returning exception %s to caller"),
+                  six.text_type(failure))
         LOG.error(tb)
 
     kwargs = {}
@@ -309,7 +311,7 @@ def serialize_remote_exception(failure_info, log_failure=True):
     data = {
         'class': str(failure.__class__.__name__),
         'module': str(failure.__class__.__module__),
-        'message': unicode(failure),
+        'message': six.text_type(failure),
         'tb': tb,
         'args': failure.args,
         'kwargs': kwargs

nova/openstack/common/rpc/impl_qpid.py

@@ -375,7 +375,7 @@ class Connection(object):
             try:
                 return method(*args, **kwargs)
             except (qpid_exceptions.Empty,
-                    qpid_exceptions.ConnectionError), e:
+                    qpid_exceptions.ConnectionError) as e:
                 if error_callback:
                     error_callback(e)
                 self.reconnect()

nova/openstack/common/rpc/impl_zmq.py

@@ -180,7 +180,7 @@ class ZmqSocket(object):
             return
 
         # We must unsubscribe, or we'll leak descriptors.
-        if len(self.subscriptions) > 0:
+        if self.subscriptions:
             for f in self.subscriptions:
                 try:
                     self.sock.setsockopt(zmq.UNSUBSCRIBE, f)
@@ -763,7 +763,7 @@ def _multi_send(method, context, topic, msg, timeout=None,
     LOG.debug(_("Sending message(s) to: %s"), queues)
 
     # Don't stack if we have no matchmaker results
-    if len(queues) == 0:
+    if not queues:
         LOG.warn(_("No matchmaker results. Not casting."))
         # While not strictly a timeout, callers know how to handle
         # this exception and a timeout isn't too big a lie.

nova/openstack/common/rpc/matchmaker.py

@@ -245,7 +245,7 @@ class HeartbeatMatchMakerBase(MatchMakerBase):
         yielding for CONF.matchmaker_heartbeat_freq seconds
         between iterations.
         """
-        if len(self.hosts) == 0:
+        if not self.hosts:
             raise MatchMakerException(
                 _("Register before starting heartbeat."))
 

tools/pip-requires

@@ -26,6 +26,7 @@ python-cinderclient>=1.0.1
 python-quantumclient>=2.2.0,<3.0.0
 python-glanceclient>=0.5.0,<2
 python-keystoneclient>=0.2.0
+six
 stevedore>=0.7
 websockify<0.4
 oslo.config>=1.1.0