Only add logging handlers if there currently aren't any

This corrects an odd problem where Horizon would stand up multiple
client objects, which would cause duplicate/triplicate/dozens of
repeated log lines in its log files, due to multiple identical
handlers being added to the logging object

Fixes Bug 1182678

Change-Id: I1f3bae0a39f28412c99e5d04f4364611f2a5facb

novaclient/client.py

@@ -91,7 +91,7 @@ class HTTPClient(object):
         self.auth_plugin = auth_plugin
 
         self._logger = logging.getLogger(__name__)
-        if self.http_log_debug:
+        if self.http_log_debug and not self._logger.handlers:
             # Logging level is already set on the root logger
             ch = logging.StreamHandler()
             self._logger.addHandler(ch)

tests/test_http.py

@@ -111,3 +111,12 @@ class ClientTest(utils.TestCase):
             self.assertRaises(exceptions.BadRequest, cl.get, "/hi")
 
         test_refused_call()
+
+    def test_client_logger(self):
+        cl1 = client.HTTPClient("username", "password", "project_id",
+                                "auth_test", http_log_debug=True)
+        self.assertEquals(len(cl1._logger.handlers), 1)
+
+        cl2 = client.HTTPClient("username", "password", "project_id",
+                                "auth_test", http_log_debug=True)
+        self.assertEquals(len(cl2._logger.handlers), 1)