Addressed feedback from review

kazoo/client.py

@@ -183,6 +183,8 @@ def __init__(
         :param use_ssl: argument to control whether SSL is used or not
         :param verify_certs: when using SSL, argument to bypass
             certs verification
+        :param check_hostname: when using SSL, check the hostname 
+            against the hostname in the cert
 
         Basic Example:
 

kazoo/handlers/utils.py

@@ -239,10 +239,10 @@ def create_tcp_connection(
 
             # Load default CA certs
             context.load_default_certs(ssl.Purpose.SERVER_AUTH)
+            if check_hostname and not verify_certs:
+                raise ValueError("Error, if check_hostname is specified, verify_certs must be False")
             # We must set check_hostname to False prior to setting
             # verify_mode to CERT_NONE.
-            # TODO: Make hostname verification configurable as some users may
-            # elect to use it.
             context.check_hostname = check_hostname
             context.verify_mode = (
                 ssl.CERT_REQUIRED if verify_certs else ssl.CERT_NONE

kazoo/tests/test_utils.py

@@ -32,7 +32,7 @@ def test_timeout_arg(self):
 
     def test_ssl_server_hostname(self):
         from kazoo.handlers import utils
-        from kazoo.handlers.utils import create_tcp_connection, ssl
+        from kazoo.handlers.utils import create_tcp_connection, socket, ssl
 
         with patch.object(utils, "_set_default_tcpsock_options"):
             with patch.object(ssl.SSLContext, "wrap_socket") as wrap_socket:
@@ -48,6 +48,40 @@ def test_ssl_server_hostname(self):
                     server_hostname = call_args[1]["server_hostname"]
                     assert server_hostname == "fakehostname"
 
+    def test_ssl_server_check_hostname(self):
+        from kazoo.handlers import utils
+        from kazoo.handlers.utils import create_tcp_connection, socket, ssl
+
+        with patch.object(utils, "_set_default_tcpsock_options"):
+            with patch.object(ssl.SSLContext, "wrap_socket", autospec=True) as wrap_socket:
+                create_tcp_connection(
+                    socket,
+                    ("127.0.0.1", 2181),
+                    timeout=1.5,
+                    hostname="fakehostname",
+                    use_ssl=True,
+                    check_hostname=True
+                )
+
+                for call_args in wrap_socket.call_args_list:
+                    ssl_context = call_args[0][0]
+                    assert ssl_context.check_hostname == True
+
+    def test_ssl_server_check_hostname_config_validation(self):
+        from kazoo.handlers import utils
+        from kazoo.handlers.utils import create_tcp_connection, socket, ssl
+
+        with pytest.raises(ValueError):
+            create_tcp_connection(
+                socket,
+                ("127.0.0.1", 2181),
+                timeout=1.5,
+                hostname="fakehostname",
+                use_ssl=True,
+                verify_certs=False,
+                check_hostname=True
+            )
+
     def test_timeout_arg_eventlet(self):
         if not EVENTLET_HANDLER_AVAILABLE:
             pytest.skip("eventlet handler not available.")