Refactored ZoneRedirect into ZoneChildHelper so ZoneManager can use this too.

4 files changed, 79 insertions, 50 deletions

diff --git a/nova/api/zone_redirect.py b/nova/api/zone_redirect.py
index fec1b1af3..0adf94046 100644
--- a/nova/api/zone_redirect.py
+++ b/nova/api/zone_redirect.py
@@ -28,6 +28,7 @@ import urllib
 from nova import exception
 from nova import log as logging
 from nova import wsgi
+from nova.scheduler import api
 
 import novaclient.client as client
 import novaclient.exceptions as osexceptions
@@ -41,6 +42,43 @@ except ImportError:
 LOG = logging.getLogger('server')
 
 
+class RequestForwarder(api.ChildZoneHelper):
+
+    def __init__(self, resource, method, body):
+        self.resource = resource
+        self.method = method
+        self.body = body
+    
+    def process(self, client, zone):
+        api_url = zone.api_url
+        LOG.debug(_("Zone redirect to: %(api_url)s, " % locals()))
+        try:
+            if self.method == 'GET':
+                response, body = client.get(self.resource, body=self.body)
+            elif self.method == 'POST':
+                response, body = client.post(self.resource, body=self.body)
+            elif self.method == 'PUT':
+                response, body = client.put(self.resource, body=self.body)
+            elif self.method == 'DELETE':
+                response, body = client.delete(self.resource, body=self.body)
+        except osexceptions.OpenStackException, e:
+            LOG.info(_("Zone returned error: %s ('%s', '%s')"),
+                                e.code, e.message, e.details)
+            res = webob.Response()
+            res.status = "404"
+            return res
+
+        status = response.status
+        LOG.debug(_("Zone %(api_url)s response: "
+                                "%(response)s [%(status)s]/ %(body)s") %
+                                    locals())
+        res = webob.Response()
+        res.status = response['status']
+        res.content_type = response['content-type']
+        res.body = json.dumps(body)
+        return res
+
+
 class ZoneRedirectMiddleware(wsgi.Middleware):
     """Catches Zone Routing exceptions and delegates the call
        to child zones."""
@@ -57,10 +95,8 @@ class ZoneRedirectMiddleware(wsgi.Middleware):
 
             # Todo(sandy): This only works for OpenStack API currently.
             # Needs to be broken out into a driver. 
-            new_req = req.copy()
-
             scheme, netloc, path, query, frag = \
-                                    urlparse.urlsplit(new_req.path_qs)
+                                    urlparse.urlsplit(req.path_qs)
             query = urlparse.parse_qsl(query)
             query = [(key, value) for key, value in query if key != 'fresh']
             query = urllib.urlencode(query)
@@ -69,38 +105,11 @@ class ZoneRedirectMiddleware(wsgi.Middleware):
             m = re.search('/v\d+\.\d+/(.+)', url)
             resource = m.group(1)
 
-            for zone in e.zones:
-                LOG.debug(_("Zone redirect to:[url:%(api_url)s, "
-                                                "username:%(username)s]"
-                            % dict(api_url=zone.api_url,
-                                            username=zone.username)))
-
-                nova = client.OpenStackClient(zone.username, zone.password,
-                                                    zone.api_url)
-                nova.authenticate()
-                try:
-                    if req.method == 'GET':
-                        response, body = nova.get(resource, body=new_req.body)
-                    elif req.method == 'POST':
-                        response, body = nova.post(resource, body=new_req.body)
-                    elif req.method == 'PUT':
-                        response, body = nova.put(resource, body=new_req.body)
-                    elif req.method == 'DELETE':
-                        response, body = nova.delete(resource,
-                                                            body=new_req.body)
-                except osexceptions.OpenStackException, e:
-                    LOG.info(_("Zone returned error: %s ('%s', '%s')"),
-                                        e.code, e.message, e.details)
-                    continue
-
-                LOG.debug(_("Zone Response: %s [%s]/ %s"), response,
-                                                        response.status, body)
-                if response.status == 200:
-                    res = webob.Response()
-                    res.status = response['status']
-                    res.content_type = response['content-type']
-                    res.body = json.dumps(body)
-                    return res
+            forwarder = RequestForwarder(resource, req.method, req.body)
+            for result in forwarder.start(e.zones):
+                # Todo(sandy): We need to aggregate multiple successes.
+                if result.status_int == 200:
+                    return result
 
             LOG.debug(_("Zone Redirect Middleware returning 404 ..."))
             res = webob.Response()
diff --git a/nova/compute/api.py b/nova/compute/api.py
index 1185b9964..215257217 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -385,9 +385,7 @@ class API(base.Base):
         if not host:
             instance = self.get(context, instance_id)
             host = instance['host']
-        #queue = self.db.queue_get_for(context, FLAGS.compute_topic, host)
-        queue = self.scheduler_api.get_queue_for_instance(context,
-                                            FLAGS.compute_topic, host)
+        queue = self.db.queue_get_for(context, FLAGS.compute_topic, host)
         params['instance_id'] = instance_id
         kwargs = {'method': method, 'args': params}
         rpc.cast(context, queue, kwargs)
@@ -406,9 +404,7 @@ class API(base.Base):
         if not host:
             instance = self.get(context, instance_id)
             host = instance["host"]
-        #queue = self.db.queue_get_for(context, FLAGS.compute_topic, host)
-        queue = self.scheduler_api.get_queue_for_instance(context,
-                                                FLAGS.compute_topic, host)
+        queue = self.db.queue_get_for(context, FLAGS.compute_topic, host)
         params['instance_id'] = instance_id
         kwargs = {'method': method, 'args': params}
         return rpc.call(context, queue, kwargs)
diff --git a/nova/scheduler/api.py b/nova/scheduler/api.py
index 48da5bcfc..073784f31 100644
--- a/nova/scheduler/api.py
+++ b/nova/scheduler/api.py
@@ -23,6 +23,10 @@ from nova import flags
 from nova import log as logging
 from nova import rpc
 
+import novaclient.client as client
+
+from eventlet import greenpool
+
 FLAGS = flags.FLAGS
 LOG = logging.getLogger('nova.scheduler.api')
 
@@ -76,6 +80,8 @@ class API(object):
         
     @classmethod
     def get_instance_or_reroute(cls, context, instance_id):
+        """Return an instance from the db or throw a ZoneRouteException
+           if not found."""
         try:
             instance = db.instance_get(context, instance_id)
             return instance
@@ -88,12 +94,30 @@ class API(object):
         zones = db.zone_get_all(context)
         raise exception.ZoneRouteException(zones)
 
-    @classmethod
-    def get_queue_for_instance(cls, context, service, instance_id):
-        instance = db.instance_get(context, instance_id)
-        zone = db.get_zone(instance.zone.id)
-        if cls._is_current_zone(zone):
-            return db.queue_get_for(context, service, instance['host'])
 
-        # Throw a reroute Exception for the middleware to pick up. 
-        raise exception.ZoneRouteException(zone)
+def _wrap_method(function, self):
+    def _wrap(*args, **kwargs):
+        return function(self, *args, **kwargs)
+    return _wrap
+
+
+def _process(self, zone):
+    nova = client.OpenStackClient(zone.username, zone.password,
+                                        zone.api_url)
+    nova.authenticate()
+    return self.process(nova, zone)
+   
+
+class ChildZoneHelper(object):
+    """Delegate a call to a set of Child Zones and wait for their
+       responses. Could be used for Zone Redirect or by the Scheduler
+       plug-ins to query the children."""
+
+    def start(self, zone_list):
+        self.green_pool = greenpool.GreenPool()
+        return [ result for result in self.green_pool.imap(
+                        _wrap_method(_process, self), zone_list)]
+  
+    def process(self, client, zone):
+        """Derived class must override."""
+        pass
diff --git a/nova/scheduler/zone_manager.py b/nova/scheduler/zone_manager.py
index c1a50dbc3..d32cc2e8f 100644
--- a/nova/scheduler/zone_manager.py
+++ b/nova/scheduler/zone_manager.py
@@ -104,7 +104,7 @@ class ZoneManager(object):
     """Keeps the zone states updated."""
     def __init__(self):
         self.last_zone_db_check = datetime.min
-        self.zone_states = {}
+        self.zone_states = {}  # { <zone_id> : ZoneState }
         self.service_states = {}  # { <service> : { <host> : { cap k : v }}}
         self.green_pool = greenpool.GreenPool()