console: make unsupported ws scheme in python < 2.7.4

Due to a bug in python < 2.7.4, urlparse won't parse a query string
in a URL where the scheme is not recognized:

http://bugs.python.org/issue9374

Commit 1dda5ef75a added some tests for
websocketproxy that uses urlparse to get a token but these don't work
on python < 2.7.4 since the scheme in the tests is "ws://".

In the actual code, raise an exception if python < 2.7.4 and an
unsupported URL scheme is used.

DocImpact: The "getting-started-with-vnc-proxy" page in the
"admin-guide-cloud" docs should be updated with a note that the web
proxy console URLs do not support the websocket protocol scheme (ws://)
on python versions less than 2.7.4.

Change-Id: Ib6e0fc4e50c1ea144a9c538099e23597d66b429b
Closes-Bug: #1376078

nova/console/websocketproxy.py

@@ -20,6 +20,7 @@ Leverages websockify.py by Joel Martin
 
 import Cookie
 import socket
+import sys
 import urlparse
 
 import websockify
@@ -43,7 +44,16 @@ class NovaProxyRequestHandlerBase(object):
 
         # The nova expected behavior is to have token
         # passed to the method GET of the request
-        query = urlparse.urlparse(self.path).query
+        parse = urlparse.urlparse(self.path)
+        if parse.scheme not in ('http', 'https'):
+            # From a bug in urlparse in Python < 2.7.4 we cannot support
+            # special schemes (cf: http://bugs.python.org/issue9374)
+            if sys.version_info < (2, 7, 4):
+                raise exception.NovaException(
+                    _("We do not support scheme '%s' under Python < 2.7.4, "
+                      "please use http or https") % parse.scheme)
+
+        query = parse.query
         token = urlparse.parse_qs(query).get("token", [""]).pop()
         if not token:
             # NoVNC uses it's own convention that forward token

nova/tests/console/test_websocketproxy.py

@@ -40,7 +40,7 @@ class NovaProxyRequestHandlerBaseTestCase(test.TestCase):
             'port': '10000'
         }
         self.wh.socket.return_value = '<socket>'
-        self.wh.path = "ws://127.0.0.1/?token=123-456-789"
+        self.wh.path = "http://127.0.0.1/?token=123-456-789"
 
         self.wh.new_websocket_client()
 
@@ -52,7 +52,7 @@ class NovaProxyRequestHandlerBaseTestCase(test.TestCase):
     def test_new_websocket_client_token_invalid(self, check_token):
         check_token.return_value = False
 
-        self.wh.path = "ws://127.0.0.1/?token=XXX"
+        self.wh.path = "http://127.0.0.1/?token=XXX"
 
         self.assertRaises(exception.InvalidToken,
                           self.wh.new_websocket_client)
@@ -97,7 +97,7 @@ class NovaProxyRequestHandlerBaseTestCase(test.TestCase):
         tsock.recv.return_value = "HTTP/1.1 200 OK\r\n\r\n"
 
         self.wh.socket.return_value = tsock
-        self.wh.path = "ws://127.0.0.1/?token=123-456-789"
+        self.wh.path = "http://127.0.0.1/?token=123-456-789"
 
         self.wh.new_websocket_client()
 
@@ -117,7 +117,40 @@ class NovaProxyRequestHandlerBaseTestCase(test.TestCase):
         tsock.recv.return_value = "HTTP/1.1 500 Internal Server Error\r\n\r\n"
 
         self.wh.socket.return_value = tsock
-        self.wh.path = "ws://127.0.0.1/?token=123-456-789"
+        self.wh.path = "http://127.0.0.1/?token=123-456-789"
 
         self.assertRaises(Exception, self.wh.new_websocket_client)  # noqa
         check_token.assert_called_with(mock.ANY, token="123-456-789")
+
+    @mock.patch('sys.version_info')
+    @mock.patch('nova.consoleauth.rpcapi.ConsoleAuthAPI.check_token')
+    def test_new_websocket_client_py273_good_scheme(
+            self, check_token, version_info):
+        version_info.return_value = (2, 7, 3)
+        check_token.return_value = {
+            'host': 'node1',
+            'port': '10000'
+        }
+        self.wh.socket.return_value = '<socket>'
+        self.wh.path = "http://127.0.0.1/?token=123-456-789"
+
+        self.wh.new_websocket_client()
+
+        check_token.assert_called_with(mock.ANY, token="123-456-789")
+        self.wh.socket.assert_called_with('node1', 10000, connect=True)
+        self.wh.do_proxy.assert_called_with('<socket>')
+
+    @mock.patch('sys.version_info')
+    @mock.patch('nova.consoleauth.rpcapi.ConsoleAuthAPI.check_token')
+    def test_new_websocket_client_py273_special_scheme(
+            self, check_token, version_info):
+        version_info.return_value = (2, 7, 3)
+        check_token.return_value = {
+            'host': 'node1',
+            'port': '10000'
+        }
+        self.wh.socket.return_value = '<socket>'
+        self.wh.path = "ws://127.0.0.1/?token=123-456-789"
+
+        self.assertRaises(exception.NovaException,
+                          self.wh.new_websocket_client)