Pass zk connection to ProviderManager.start()

In order to support static node pre-registration, we need to give
the provider manager the opportunity to register/deregister any
nodes in its configuration file when it starts (on startup or when
the config change). It will need a ZooKeeper connection to do this.
The OpenStack driver will ignore this parameter.

Change-Id: Idd00286b2577921b3fe5b55e8f13a27f2fbde5d6

nodepool/builder.py

@@ -536,6 +536,7 @@ class CleanupWorker(BaseWorker):
 
         self._checkForZooKeeperChanges(new_config)
         provider_manager.ProviderManager.reconfigure(self._config, new_config,
+                                                     self._zk,
                                                      use_taskmanager=False)
         self._config = new_config
 
@@ -878,6 +879,7 @@ class UploadWorker(BaseWorker):
 
         self._checkForZooKeeperChanges(new_config)
         provider_manager.ProviderManager.reconfigure(self._config, new_config,
+                                                     self._zk,
                                                      use_taskmanager=False)
         self._config = new_config
 

nodepool/cmd/nodepoolcmd.py

@@ -251,7 +251,7 @@ class NodePoolCmd(NodepoolApp):
                 return
             provider = self.pool.config.providers[node.provider]
             manager = provider_manager.get_provider(provider, True)
-            manager.start()
+            manager.start(self.zk)
             launcher.NodeDeleter.delete(self.zk, manager, node)
             manager.stop()
         else:

nodepool/driver/__init__.py

@@ -145,11 +145,15 @@ class Provider(object, metaclass=abc.ABCMeta):
 
     """
     @abc.abstractmethod
-    def start(self):
+    def start(self, zk_conn):
         """Start this provider
 
+        :param ZooKeeper zk_conn: A ZooKeeper connection object.
+
         This is called after each configuration change to allow the driver
-        to perform initialization tasks and start background threads.
+        to perform initialization tasks and start background threads. The
+        ZooKeeper connection object is provided if the Provider needs to
+        interact with it.
 
         """
         pass

nodepool/driver/openstack/provider.py

@@ -118,7 +118,7 @@ class OpenStackProvider(Provider):
         self._taskmanager = None
         self._current_nodepool_quota = None
 
-    def start(self):
+    def start(self, zk_conn):
         if self._use_taskmanager:
             self._taskmanager = TaskManager(None, self.provider.name,
                                             self.provider.rate)

nodepool/driver/static/provider.py

@@ -57,7 +57,7 @@ class StaticNodeProvider(Provider):
         raise StaticNodeError("%s: host key mismatches (%s)" %
                               (node["name"], keys))
 
-    def start(self):
+    def start(self, zk_conn):
         for pool in self.provider.pools.values():
             self.pools[pool.name] = {}
             for node in pool.nodes:

nodepool/driver/test/provider.py

@@ -22,7 +22,7 @@ class TestProvider(Provider):
     def __init__(self, provider):
         self.provider = provider
 
-    def start(self):
+    def start(self, zk_conn):
         pass
 
     def stop(self):

nodepool/launcher.py

@@ -819,8 +819,9 @@ class NodePool(threading.Thread):
 
     def updateConfig(self):
         config = self.loadConfig()
-        provider_manager.ProviderManager.reconfigure(self.config, config)
         self.reconfigureZooKeeper(config)
+        provider_manager.ProviderManager.reconfigure(self.config, config,
+                                                     self.getZK())
         self.setConfig(config)
 
     def removeCompletedRequests(self):

nodepool/provider_manager.py

@@ -30,7 +30,18 @@ class ProviderManager(object):
     log = logging.getLogger("nodepool.ProviderManager")
 
     @staticmethod
-    def reconfigure(old_config, new_config, use_taskmanager=True):
+    def reconfigure(old_config, new_config, zk_conn, use_taskmanager=True):
+        '''
+        Reconfigure the provider managers on any configuration changes.
+
+        If a provider configuration changes, stop the current provider
+        manager we have cached and replace it with a new one.
+
+        :param Config old_config: The previously read configuration.
+        :param Config new_config: The newly read configuration.
+        :param ZooKeeper zk_conn: A ZooKeeper connection object.
+        :param bool use_taskmanager: If True, use a task manager.
+        '''
         stop_managers = []
         for p in new_config.providers.values():
             oldmanager = None
@@ -46,7 +57,7 @@ class ProviderManager(object):
                                           " for %s" % p.name)
                 new_config.provider_managers[p.name] = \
                     get_provider(p, use_taskmanager)
-                new_config.provider_managers[p.name].start()
+                new_config.provider_managers[p.name].start(zk_conn)
 
         for stop_manager in stop_managers:
             stop_manager.stop()

nodepool/tests/test_shade_integration.py

@@ -61,7 +61,7 @@ class TestShadeIntegration(tests.IntegrationTestCase):
         self.assertIn('real-provider', config.providers)
         pm = provider_manager.get_provider(
             config.providers['real-provider'], use_taskmanager=False)
-        pm.start()
+        pm.start(None)
         self.assertEqual(pm._client.auth, auth_data)
 
     def test_nodepool_occ_config_reload(self):