Update some variable names

Now that the component we registered is a "pool" change the call
sites to use "launcher_pools" instead of "launchers".  This may
reduce some ambiguity.

(s/launcher/pool/ might still be ambiguous since it may not be clear
whethere we're talking about our own pools or other pools; thus the
choice of "launcher_pool" for the variable name.)

Also, remove a redundant test assertion.

Change-Id: I865883cdb115bf72a3bd034d9290f60666d64b66

nodepool/driver/__init__.py

@@ -641,9 +641,9 @@ class NodeRequestHandler(NodeRequestHandlerNotifications,
         # want to make sure we don't continuously grow this array.
         if self.launcher_id not in self.request.declined_by:
             self.request.declined_by.append(self.launcher_id)
-        launchers = set([x.id for x in self.zk.getRegisteredPools()])
-        if launchers.issubset(set(self.request.declined_by)):
-            # All launchers have declined it
+        launcher_pools = set([x.id for x in self.zk.getRegisteredPools()])
+        if launcher_pools.issubset(set(self.request.declined_by)):
+            # All launcher_pools have declined it
             self.log.debug("Failing declined node request")
             self.request.state = zk.FAILED
         else:

nodepool/launcher.py

@@ -121,7 +121,7 @@ class PoolWorker(threading.Thread, stats.StatsReporter):
         # become out of date as the loop progresses, but it should be
         # good enough to determine whether we should process requests
         # which express a preference for a specific provider.
-        launchers = self.zk.getRegisteredPools()
+        launcher_pools = self.zk.getRegisteredPools()
 
         pm = self.getProviderManager()
         has_quota_support = isinstance(pm, QuotaSupport)
@@ -180,8 +180,8 @@ class PoolWorker(threading.Thread, stats.StatsReporter):
             log = get_annotated_logger(self.log, event_id=req.event_id,
                                        node_request_id=req.id)
             # Get the candidate launchers for these nodes
-            candidate_launchers = set(
-                x for x in launchers
+            candidate_launcher_pools = set(
+                x for x in launcher_pools
                 if (set(x.supported_labels).issuperset(set(req.node_types)) and
                     x.id not in req.declined_by)
             )
@@ -189,26 +189,26 @@ class PoolWorker(threading.Thread, stats.StatsReporter):
             # which is online
             if req.provider and req.provider != self.provider_name:
                 # The request is asking for a specific provider
-                launcher_ids_for_provider = set(
-                    x.id for x in candidate_launchers
+                launcher_pool_ids_for_provider = set(
+                    x.id for x in candidate_launcher_pools
                     if x.provider_name == req.provider
                 )
-                if launcher_ids_for_provider:
+                if launcher_pool_ids_for_provider:
                     # There is a launcher online which can satisfy the
                     # request that has not yet declined the request,
                     # so yield to it.
                     log.debug("Yielding request to provider %s %s",
-                              req.provider, launcher_ids_for_provider)
+                              req.provider, launcher_pool_ids_for_provider)
                     continue
 
             priority = self.getPriority()
-            launcher_ids_with_higher_priority = set(
-                x.id for x in candidate_launchers
+            launcher_pool_ids_with_higher_priority = set(
+                x.id for x in candidate_launcher_pools
                 if x.priority < priority and not x.paused
             )
-            if launcher_ids_with_higher_priority:
+            if launcher_pool_ids_with_higher_priority:
                 log.debug("Yielding request to higher priority providers %s",
-                          launcher_ids_with_higher_priority)
+                          launcher_pool_ids_with_higher_priority)
                 continue
 
             if has_quota_support and not all(label_quota.get(l, math.inf) > 0

nodepool/stats.py

@@ -98,13 +98,13 @@ class StatsReporter(object):
 
         states = {}
 
-        launchers = zk_conn.getRegisteredPools()
+        launcher_pools = zk_conn.getRegisteredPools()
         labels = set()
-        for launcher in launchers:
-            labels.update(launcher.supported_labels)
+        for launcher_pool in launcher_pools:
+            labels.update(launcher_pool.supported_labels)
         providers = set()
-        for launcher in launchers:
-            providers.add(launcher.provider_name)
+        for launcher_pool in launcher_pools:
+            providers.add(launcher_pool.provider_name)
 
         # Initialize things we know about to zero
         for state in zk.Node.VALID_STATES:

nodepool/status.py

@@ -267,9 +267,9 @@ def label_list(zk):
     # NOTE(ianw): maybe add to each entry a list of which
     #             launchers support the label?
     labels = set()
-    launchers = zk.getRegisteredPools()
-    for launcher in launchers:
-        labels.update(set(launcher.supported_labels))
+    launcher_pools = zk.getRegisteredPools()
+    for launcher_pool in launcher_pools:
+        labels.update(set(launcher_pool.supported_labels))
 
     for label in labels:
         objs.append({'label': label})

nodepool/tests/unit/test_launcher.py

@@ -1669,7 +1669,6 @@ class TestLauncher(tests.DBTestCase):
         self.assertEqual('secret', fake_image.env_vars['REG_PASSWORD'])
 
         zk_servers = pool.config.zookeeper_servers
-        self.assertTrue(len(zk_servers) > 0)
         expected = (f'{self.zookeeper_host}:{self.zookeeper_port}'
                     f'{self.zookeeper_chroot}')
         self.assertEqual(expected, zk_servers)
@@ -1924,19 +1923,20 @@ class TestLauncher(tests.DBTestCase):
         pool.start()
 
         self.waitForNodes('fake-label')
-        launchers = self.zk.getRegisteredPools()
-        self.assertEqual(1, len(launchers))
+        launcher_pools = self.zk.getRegisteredPools()
+        self.assertEqual(1, len(launcher_pools))
 
         # the fake-label-unused label should not appear
-        self.assertEqual({'fake-label'}, set(launchers[0].supported_labels))
+        self.assertEqual({'fake-label'},
+                         set(launcher_pools[0].supported_labels))
 
         self.replace_config(configfile, 'launcher_reg2.yaml')
 
         # we should get 1 additional label now
-        while (set(launchers[0].supported_labels) !=
+        while (set(launcher_pools[0].supported_labels) !=
                {'fake-label', 'fake-label2'}):
             time.sleep(1)
-            launchers = self.zk.getRegisteredPools()
+            launcher_pools = self.zk.getRegisteredPools()
 
     @mock.patch('nodepool.driver.openstack.handler.'
                 'OpenStackNodeLauncher._launchNode')

nodepool/tests/unit/test_zk.py

@@ -40,13 +40,13 @@ class TestComponentRegistry(tests.DBTestCase):
         })
         launcher.register()
 
-        launchers = self.zk.getRegisteredPools()
-        self.assertEqual(1, len(launchers))
-        self.assertEqual(launcher.id, list(launchers)[0].id)
+        launcher_pools = self.zk.getRegisteredPools()
+        self.assertEqual(1, len(launcher_pools))
+        self.assertEqual(launcher.id, list(launcher_pools)[0].id)
 
         launcher.unregister()
-        launchers = self.zk.getRegisteredPools()
-        self.assertEqual(0, len(launchers))
+        launcher_pools = self.zk.getRegisteredPools()
+        self.assertEqual(0, len(launcher_pools))
 
 
 class TestZooKeeper(tests.DBTestCase):