tests and fix for PYTHON-895

Author: mambocab

cassandra/__init__.py

@@ -686,3 +686,13 @@ class UnsupportedOperation(DriverException):
     for more details.
     """
     pass
+
+
+class UnresolvableContactPoints(DriverException):
+    """
+    The driver was unable to resolve any provided hostnames.
+
+    Note that this is *not* raised when a :class:`.Cluster` is created with no
+    contact points, only when lookup fails for all hosts
+    """
+    pass

cassandra/cluster.py

@@ -43,7 +43,8 @@
 
 from cassandra import (ConsistencyLevel, AuthenticationFailed,
                        OperationTimedOut, UnsupportedOperation,
-                       SchemaTargetType, DriverException, ProtocolVersion)
+                       SchemaTargetType, DriverException, ProtocolVersion,
+                       UnresolvableContactPoints)
 from cassandra.connection import (ConnectionException, ConnectionShutdown,
                                   ConnectionHeartbeat, ProtocolVersionUnsupported)
 from cassandra.cqltypes import UserType
@@ -201,10 +202,26 @@ def _addrinfo_or_none(contact_point, port):
     try:
         return socket.getaddrinfo(contact_point, port,
                                   socket.AF_UNSPEC, socket.SOCK_STREAM)
-    except (socket.error, socket.herror, socket.gaierror, socket.timeout):
+    except socket.gaierror:
+        log.debug('Could not resolve hostname "{}" '
+                  'with port {}'.format(contact_point, port))
         return None
 
 
+def _resolve_contact_points(contact_points, port):
+    resolved = tuple(_addrinfo_or_none(p, port)
+                     for p in contact_points)
+
+    if resolved and all((x is None for x in resolved)):
+        raise UnresolvableContactPoints(contact_points, port)
+
+    resolved = tuple(r for r in resolved if r is not None)
+
+    return [endpoint[4][0]
+            for addrinfo in resolved
+            for endpoint in addrinfo]
+
+
 class ExecutionProfile(object):
     load_balancing_policy = None
     """
@@ -837,12 +854,8 @@ def __init__(self,
 
         self.port = port
 
-        self.contact_points_resolved = [
-            endpoint[4][0]
-            for point in self.contact_points
-            for endpoint in _addrinfo_or_none(point, self.port)
-            if endpoint is not None
-        ]
+        self.contact_points_resolved = _resolve_contact_points(self.contact_points,
+                                                               self.port)
 
         self.compression = compression
 

tests/integration/simulacron/__init__.py

@@ -35,20 +35,25 @@ def tearDown(self):
 
 
 class SimulacronCluster(SimulacronBase):
+
+    cluster, connect = None, True
+
     @classmethod
     def setUpClass(cls):
         if SIMULACRON_JAR is None or CASSANDRA_VERSION < Version("2.1"):
             return
 
         start_and_prime_singledc()
-        cls.cluster = Cluster(protocol_version=PROTOCOL_VERSION, compression=False)
-        cls.session = cls.cluster.connect(wait_for_all_pools=True)
+        if cls.connect:
+            cls.cluster = Cluster(protocol_version=PROTOCOL_VERSION, compression=False)
+            cls.session = cls.cluster.connect(wait_for_all_pools=True)
 
     @classmethod
     def tearDownClass(cls):
         if SIMULACRON_JAR is None or CASSANDRA_VERSION < Version("2.1"):
             return
 
-        cls.cluster.shutdown()
+        if cls.cluster:
+            cls.cluster.shutdown()
         stop_simulacron()
 

tests/integration/simulacron/test_cluster.py

@@ -20,7 +20,8 @@
 from tests.integration import (requiressimulacron, PROTOCOL_VERSION)
 from tests.integration.simulacron.utils import prime_query
 
-from cassandra import WriteTimeout, WriteType, ConsistencyLevel
+from cassandra import (WriteTimeout, WriteType,
+                       ConsistencyLevel, UnresolvableContactPoints)
 from cassandra.cluster import Cluster
 
 
@@ -56,18 +57,24 @@ def test_writetimeout(self):
         self.assertIn(str(received_responses), str(wt))
         self.assertIn(str(required_responses), str(wt))
 
-    def test_connection_with_one_unresolvable_contact_point(self):
-        self.cluster.shutdown()
 
-        # shouldn't raise anything due to name resolution failures
-        Cluster(['127.0.0.1', 'doesntresolve.becauseitcant'],
-                protocol_version=PROTOCOL_VERSION,
-                compression=False)
+@requiressimulacron
+class ClusterDNSResolutionTests(SimulacronCluster):
 
-    def test_connection_with_only_unresolvable_contact_points(self):
-        self.cluster.shutdown()
+    connect = False
 
+    def tearDown(self):
+        if self.cluster:
+            self.cluster.shutdown()
+
+    def test_connection_with_one_unresolvable_contact_point(self):
         # shouldn't raise anything due to name resolution failures
-        Cluster(['doesntresolve.becauseitcant'],
-                protocol_version=PROTOCOL_VERSION,
-                compression=False)
+        self.cluster = Cluster(['127.0.0.1', 'dns.invalid'],
+                               protocol_version=PROTOCOL_VERSION,
+                               compression=False)
+
+    def test_connection_with_only_unresolvable_contact_points(self):
+        with self.assertRaises(UnresolvableContactPoints):
+            self.cluster = Cluster(['dns.invalid'],
+                                   protocol_version=PROTOCOL_VERSION,
+                                   compression=False)