Extract matchmaker_ring to own module

The base matchmaker module should not have
all the matchmakers implemented within. Instead,
we desire to break them out.

For purposes of deprecation, logs a warning when
importing from the ZeroMQ driver.

Change-Id: I76936edd97309621a9c28363dccd792293a1c0d3

4 files changed, 123 insertions, 81 deletions

diff --git a/openstack/common/rpc/impl_zmq.py b/openstack/common/rpc/impl_zmq.py
index fec299c..add3973 100644
--- a/openstack/common/rpc/impl_zmq.py
+++ b/openstack/common/rpc/impl_zmq.py
@@ -846,6 +846,11 @@ def _get_ctxt():
 def _get_matchmaker(*args, **kwargs):
     global matchmaker
     if not matchmaker:
-        matchmaker = importutils.import_object(
-            CONF.rpc_zmq_matchmaker, *args, **kwargs)
+        mm = CONF.rpc_zmq_matchmaker
+        if mm.endswith('matchmaker.MatchMakerRing'):
+            mm.replace('matchmaker', 'matchmaker_ring')
+            LOG.warn(_('rpc_zmq_matchmaker = %(orig)s is deprecated; use'
+                       ' %(new)s instead') % dict(
+                     orig=CONF.rpc_zmq_matchmaker, new=mm))
+        matchmaker = importutils.import_object(mm, *args, **kwargs)
     return matchmaker
diff --git a/openstack/common/rpc/matchmaker.py b/openstack/common/rpc/matchmaker.py
index 3d72ae7..8072023 100644
--- a/openstack/common/rpc/matchmaker.py
+++ b/openstack/common/rpc/matchmaker.py
@@ -19,8 +19,6 @@ return keys for direct exchanges, per (approximate) AMQP parlance.
 """
 
 import contextlib
-import itertools
-import json
 
 import eventlet
 from oslo.config import cfg
@@ -30,10 +28,6 @@ from openstack.common import log as logging
 
 
 matchmaker_opts = [
-    # Matchmaker ring file
-    cfg.StrOpt('matchmaker_ringfile',
-               default='/etc/nova/matchmaker_ring.json',
-               help='Matchmaker ring file (JSON)'),
     cfg.IntOpt('matchmaker_heartbeat_freq',
                default=300,
                help='Heartbeat frequency'),
@@ -304,67 +298,6 @@ class StubExchange(Exchange):
         return [(key, None)]
 
 
-class RingExchange(Exchange):
-    """
-    Match Maker where hosts are loaded from a static file containing
-    a hashmap (JSON formatted).
-
-    __init__ takes optional ring dictionary argument, otherwise
-    loads the ringfile from CONF.mathcmaker_ringfile.
-    """
-    def __init__(self, ring=None):
-        super(RingExchange, self).__init__()
-
-        if ring:
-            self.ring = ring
-        else:
-            fh = open(CONF.matchmaker_ringfile, 'r')
-            self.ring = json.load(fh)
-            fh.close()
-
-        self.ring0 = {}
-        for k in self.ring.keys():
-            self.ring0[k] = itertools.cycle(self.ring[k])
-
-    def _ring_has(self, key):
-        if key in self.ring0:
-            return True
-        return False
-
-
-class RoundRobinRingExchange(RingExchange):
-    """A Topic Exchange based on a hashmap."""
-    def __init__(self, ring=None):
-        super(RoundRobinRingExchange, self).__init__(ring)
-
-    def run(self, key):
-        if not self._ring_has(key):
-            LOG.warn(
-                _("No key defining hosts for topic '%s', "
-                  "see ringfile") % (key, )
-            )
-            return []
-        host = next(self.ring0[key])
-        return [(key + '.' + host, host)]
-
-
-class FanoutRingExchange(RingExchange):
-    """Fanout Exchange based on a hashmap."""
-    def __init__(self, ring=None):
-        super(FanoutRingExchange, self).__init__(ring)
-
-    def run(self, key):
-        # Assume starts with "fanout~", strip it for lookup.
-        nkey = key.split('fanout~')[1:][0]
-        if not self._ring_has(nkey):
-            LOG.warn(
-                _("No key defining hosts for topic '%s', "
-                  "see ringfile") % (nkey, )
-            )
-            return []
-        return map(lambda x: (key + '.' + x, x), self.ring[nkey])
-
-
 class LocalhostExchange(Exchange):
     """Exchange where all direct topics are local."""
     def __init__(self, host='localhost'):
@@ -388,17 +321,6 @@ class DirectExchange(Exchange):
         return [(key, e)]
 
 
-class MatchMakerRing(MatchMakerBase):
-    """
-    Match Maker where hosts are loaded from a static hashmap.
-    """
-    def __init__(self, ring=None):
-        super(MatchMakerRing, self).__init__()
-        self.add_binding(FanoutBinding(), FanoutRingExchange(ring))
-        self.add_binding(DirectBinding(), DirectExchange())
-        self.add_binding(TopicBinding(), RoundRobinRingExchange(ring))
-
-
 class MatchMakerLocalhost(MatchMakerBase):
     """
     Match Maker where all bare topics resolve to localhost.
diff --git a/openstack/common/rpc/matchmaker_ring.py b/openstack/common/rpc/matchmaker_ring.py
new file mode 100644
index 0000000..dbfb36f
--- /dev/null
+++ b/openstack/common/rpc/matchmaker_ring.py
@@ -0,0 +1,114 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#    Copyright 2011-2013 Cloudscaling Group, Inc
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+"""
+The MatchMaker classes should except a Topic or Fanout exchange key and
+return keys for direct exchanges, per (approximate) AMQP parlance.
+"""
+
+import itertools
+import json
+
+from oslo.config import cfg
+
+from openstack.common.gettextutils import _
+from openstack.common import log as logging
+from openstack.common.rpc import matchmaker as mm
+
+
+matchmaker_opts = [
+    # Matchmaker ring file
+    cfg.StrOpt('ringfile',
+               deprecated_name='matchmaker_ringfile',
+               deprecated_group='DEFAULT',
+               default='/etc/oslo/matchmaker_ring.json',
+               help='Matchmaker ring file (JSON)'),
+]
+
+CONF = cfg.CONF
+CONF.register_opts(matchmaker_opts, 'matchmaker_ring')
+LOG = logging.getLogger(__name__)
+
+
+class RingExchange(mm.Exchange):
+    """
+    Match Maker where hosts are loaded from a static file containing
+    a hashmap (JSON formatted).
+
+    __init__ takes optional ring dictionary argument, otherwise
+    loads the ringfile from CONF.mathcmaker_ringfile.
+    """
+    def __init__(self, ring=None):
+        super(RingExchange, self).__init__()
+
+        if ring:
+            self.ring = ring
+        else:
+            fh = open(CONF.matchmaker_ring.ringfile, 'r')
+            self.ring = json.load(fh)
+            fh.close()
+
+        self.ring0 = {}
+        for k in self.ring.keys():
+            self.ring0[k] = itertools.cycle(self.ring[k])
+
+    def _ring_has(self, key):
+        if key in self.ring0:
+            return True
+        return False
+
+
+class RoundRobinRingExchange(RingExchange):
+    """A Topic Exchange based on a hashmap."""
+    def __init__(self, ring=None):
+        super(RoundRobinRingExchange, self).__init__(ring)
+
+    def run(self, key):
+        if not self._ring_has(key):
+            LOG.warn(
+                _("No key defining hosts for topic '%s', "
+                  "see ringfile") % (key, )
+            )
+            return []
+        host = next(self.ring0[key])
+        return [(key + '.' + host, host)]
+
+
+class FanoutRingExchange(RingExchange):
+    """Fanout Exchange based on a hashmap."""
+    def __init__(self, ring=None):
+        super(FanoutRingExchange, self).__init__(ring)
+
+    def run(self, key):
+        # Assume starts with "fanout~", strip it for lookup.
+        nkey = key.split('fanout~')[1:][0]
+        if not self._ring_has(nkey):
+            LOG.warn(
+                _("No key defining hosts for topic '%s', "
+                  "see ringfile") % (nkey, )
+            )
+            return []
+        return map(lambda x: (key + '.' + x, x), self.ring[nkey])
+
+
+class MatchMakerRing(mm.MatchMakerBase):
+    """
+    Match Maker where hosts are loaded from a static hashmap.
+    """
+    def __init__(self, ring=None):
+        super(MatchMakerRing, self).__init__()
+        self.add_binding(mm.FanoutBinding(), FanoutRingExchange(ring))
+        self.add_binding(mm.DirectBinding(), mm.DirectExchange())
+        self.add_binding(mm.TopicBinding(), RoundRobinRingExchange(ring))
diff --git a/tests/unit/rpc/test_matchmaker.py b/tests/unit/rpc/test_matchmaker.py
index bcc7ef8..71688a4 100644
--- a/tests/unit/rpc/test_matchmaker.py
+++ b/tests/unit/rpc/test_matchmaker.py
@@ -17,6 +17,7 @@
 import logging
 
 from openstack.common.rpc import matchmaker
+from openstack.common.rpc import matchmaker_ring
 from tests.unit.rpc import matchmaker_common as common
 from tests import utils
 
@@ -32,7 +33,7 @@ class MatchMakerFileTestCase(utils.BaseTestCase, common._MatchMakerTestCase):
         ring = {
             self.topic: self.hosts
         }
-        self.driver = matchmaker.MatchMakerRing(ring)
+        self.driver = matchmaker_ring.MatchMakerRing(ring)
 
 
 class MatchMakerLocalhostTestCase(utils.BaseTestCase,