Include unsupported url scheme with ClientException

This was an attempt to reveal some more info about failing
jenkins jobs such as here [1] where glance_store is
receiving a swiftclient exception because of 'unsupported
scheme in url'. It seems worth merging the more helpful
exception message.

[1] http://logs.openstack.org/91/155291/7/check/gate-tempest-dsvm-neutron-src-python-swiftclient/4adac1e/

Change-Id: I0f3411efd42d045b07d6d1000f59a06865d8034b

swiftclient/client.py

@@ -170,7 +170,8 @@ class HTTPConnection(object):
         self.requests_args = {}
         self.request_session = requests.Session()
         if self.parsed_url.scheme not in ('http', 'https'):
-            raise ClientException("Unsupported scheme")
+            raise ClientException('Unsupported scheme "%s" in url "%s"'
+                                  % (self.parsed_url.scheme, url))
         self.requests_args['verify'] = not insecure
         if cacert and not insecure:
             # verify requests parameter is used to pass the CA_BUNDLE file

tests/unit/test_swiftclient.py

@@ -975,6 +975,29 @@ class TestGetCapabilities(MockHttpTest):
 
 class TestHTTPConnection(MockHttpTest):
 
+    def test_bad_url_scheme(self):
+        url = u'www.test.com'
+        exc = self.assertRaises(c.ClientException, c.http_connection, url)
+        expected = u'Unsupported scheme "" in url "www.test.com"'
+        self.assertEqual(expected, str(exc))
+
+        url = u'://www.test.com'
+        exc = self.assertRaises(c.ClientException, c.http_connection, url)
+        expected = u'Unsupported scheme "" in url "://www.test.com"'
+        self.assertEqual(expected, str(exc))
+
+        url = u'blah://www.test.com'
+        exc = self.assertRaises(c.ClientException, c.http_connection, url)
+        expected = u'Unsupported scheme "blah" in url "blah://www.test.com"'
+        self.assertEqual(expected, str(exc))
+
+    def test_ok_url_scheme(self):
+        for scheme in ('http', 'https', 'HTTP', 'HTTPS'):
+            url = u'%s://www.test.com' % scheme
+            parsed_url, conn = c.http_connection(url)
+            self.assertEqual(scheme.lower(), parsed_url.scheme)
+            self.assertEqual(u'%s://www.test.com' % scheme, conn.url)
+
     def test_ok_proxy(self):
         conn = c.http_connection(u'http://www.test.com/',
                                  proxy='http://localhost:8080')