Add a comment and some in-direct test for connection re-use / making

sure self.connect() is only called if connection details (scheme, host,
port) change.

libcloud/common/openstack.py

@@ -362,6 +362,8 @@ def _set_up_connection_info(self, url):
         (self.host, self.port, self.secure, self.request_path) = result
         new_conn = (self.host, self.port, self.secure)
         if new_conn != prev_conn:
+            # We only call connect in case connection details have changed - this way we correctly
+            # re-use connection in case nothing has changed
             self.connect()
 
     def _populate_hosts_and_request_paths(self):

libcloud/test/common/test_openstack.py

@@ -76,6 +76,47 @@ def test_request(self, mock_request):
             raw=False,
         )
 
+    @patch("libcloud.test.common.test_openstack.OpenStackBaseConnection.connect", Mock())
+    def test_connection_is_reused_when_details_dont_change(self):
+        url = "https://example.com"
+
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 1)
+
+        for index in range(0, 10):
+            self.connection._set_up_connection_info(url=url)
+            self.assertEqual(self.connection.connect.call_count, 1)
+
+    @patch("libcloud.test.common.test_openstack.OpenStackBaseConnection.connect", Mock())
+    def test_connection_is_not_reused_when_details_change(self):
+        url = "https://example.com"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 1)
+
+        url = "https://example.com"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 1)
+
+        url = "https://example.com:80"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 2)
+
+        url = "http://example.com:80"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 3)
+
+        url = "http://exxample.com:80"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 4)
+
+        url = "http://exxample.com:81"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 5)
+
+        url = "http://exxample.com:81"
+        self.connection._set_up_connection_info(url=url)
+        self.assertEqual(self.connection.connect.call_count, 5)
+
 
 if __name__ == "__main__":
     sys.exit(unittest.main())