Add support for versionless endpoints

Newer deployments are using versionless Keystone endpoints, and most
OpenStack clients already support this.

This patch enables this for Swift: if an auth_url without any path
component is found, it assumes a versionless endpoint will be used.
In this case the v3 suffix will be appended to the path if none
auth_version is set, and v2.0 is appended if auth_version requires v2.

Closes-Bug: 1554885
Related-Bug: 1691106
Change-Id: If7ecb67776cb77828f93ad8278cc5040015216b7

swiftclient/client.py

@@ -25,7 +25,7 @@ from distutils.version import StrictVersion
 from requests.exceptions import RequestException, SSLError
 from six.moves import http_client
 from six.moves.urllib.parse import quote as _quote, unquote
-from six.moves.urllib.parse import urlparse, urlunparse
+from six.moves.urllib.parse import urljoin, urlparse, urlunparse
 from time import sleep, time
 import six
 
@@ -550,9 +550,22 @@ def get_auth_keystone(auth_url, user, key, os_options, **kwargs):
 
     insecure = kwargs.get('insecure', False)
     timeout = kwargs.get('timeout', None)
-    auth_version = kwargs.get('auth_version', '2.0')
+    auth_version = kwargs.get('auth_version', None)
     debug = logger.isEnabledFor(logging.DEBUG)
 
+    # Add the version suffix in case of versionless Keystone endpoints. If
+    # auth_version is also unset it is likely that it is v3
+    if len(urlparse(auth_url).path) <= 1:
+        if auth_version and auth_version in AUTH_VERSIONS_V2:
+            auth_url = urljoin(auth_url, "v2.0")
+        else:
+            auth_url = urljoin(auth_url, "v3")
+            auth_version = '3'
+        logger.debug("Versionless auth_url - using %s as endpoint" % auth_url)
+
+    # Legacy default if not set
+    if auth_version is None:
+        auth_version = 'v2.0'
     ksclient, exceptions = _import_keystone_client(auth_version)
 
     try:

tests/unit/test_swiftclient.py

@@ -575,6 +575,26 @@ class TestGetAuth(MockHttpTest):
         self.assertTrue(url.startswith("http"))
         self.assertTrue(token)
 
+    def test_get_auth_keystone_versionless(self):
+        fake_ks = FakeKeystone(endpoint='http://some_url', token='secret')
+
+        with mock.patch('swiftclient.client._import_keystone_client',
+                        _make_fake_import_keystone_client(fake_ks)):
+            c.get_auth_keystone('http://authurl', 'user', 'key', {})
+        self.assertEqual(1, len(fake_ks.calls))
+        self.assertEqual('http://authurl/v3', fake_ks.calls[0].get('auth_url'))
+
+    def test_get_auth_keystone_versionless_auth_version_set(self):
+        fake_ks = FakeKeystone(endpoint='http://some_url', token='secret')
+
+        with mock.patch('swiftclient.client._import_keystone_client',
+                        _make_fake_import_keystone_client(fake_ks)):
+            c.get_auth_keystone('http://auth_url', 'user', 'key',
+                                {}, auth_version='2.0')
+        self.assertEqual(1, len(fake_ks.calls))
+        self.assertEqual('http://auth_url/v2.0',
+                         fake_ks.calls[0].get('auth_url'))
+
     def test_auth_with_session(self):
         mock_session = mock.MagicMock()
         mock_session.get_endpoint.return_value = 'http://storagehost/v1/acct'