Drop webob from auth_token.py

This came up as a packaging problem in Fedora. Now that Swift does
not need python-webob RPM, some sites install a proxy node without.
We add the proper webob dependency to the python-keystoneclient.
Still, in the face of parallel installs, and we end patching
setup.py and diverge from upstream, and we do not like it.

It may be better just stick to WSGI protocol by small amount of
hand-rolled code and drop WebOb altogether.

Note that we keep WebOb in the testing code. The fix is purely
about the stuff that runs inside a WSGI server. Therefore,
requirements.txt continues having no WebOb (apparently, was
forgotten before), but test-requirements.txt keeps WebOb in,
and this patch changes nothing.

Initial version of this patch produced an inexplicable drop in
testing coverage and Chmouel put his foot down on it. We were
unable to figure out why the drop happened. Most likely coverage
simply lied about the previous percentages and getting rid of
import webob permitted it a better analysis. So, we add some
unrelated tests to bump coverage percentages up.

Of course we add a targeted test for the new code too. For that
one to work, we change how set_middleware() treats its fake_http
argument.

This version also adds comments rather than docstrings, because
they need to source as context.

Change-Id: Iba33b11e77b9910211983aa725c69d3886e1c7a7

keystoneclient/middleware/auth_token.py

@@ -153,7 +153,6 @@ import stat
 import tempfile
 import time
 import urllib
-import webob.exc
 
 from keystoneclient.openstack.common import jsonutils
 from keystoneclient.common import cms
@@ -252,6 +251,19 @@ class ConfigurationError(Exception):
     pass
 
 
+class MiniResp(object):
+    def __init__(self, error_message, env, headers=[]):
+        # The HEAD method is unique: it must never return a body, even if
+        # it reports an error (RFC-2616 clause 9.4). We relieve callers
+        # from varying the error responses depending on the method.
+        if env['REQUEST_METHOD'] == 'HEAD':
+            self.body = ['']
+        else:
+            self.body = [error_message]
+        self.headers = list(headers)
+        self.headers.append(('Content-type', 'text/plain'))
+
+
 class AuthProtocol(object):
     """Auth Middleware that handles authenticating client calls."""
 
@@ -472,8 +484,9 @@ class AuthProtocol(object):
 
         except ServiceError as e:
             self.LOG.critical('Unable to obtain admin token: %s' % e)
-            resp = webob.exc.HTTPServiceUnavailable()
-            return resp(env, start_response)
+            resp = MiniResp('Service unavailable', env)
+            start_response('503 Service Unavailable', resp.headers)
+            return resp.body
 
     def _remove_auth_headers(self, env):
         """Remove headers so a user can't fake authentication.
@@ -534,8 +547,9 @@ class AuthProtocol(object):
 
         """
         headers = [('WWW-Authenticate', 'Keystone uri=\'%s\'' % self.auth_uri)]
-        resp = webob.exc.HTTPUnauthorized('Authentication required', headers)
-        return resp(env, start_response)
+        resp = MiniResp('Authentication required', env, headers)
+        start_response('401 Unauthorized', resp.headers)
+        return resp.body
 
     def get_admin_token(self):
         """Return admin token, possibly fetching a new one.

tests/test_auth_token_middleware.py

@@ -17,6 +17,7 @@
 import datetime
 import iso8601
 import os
+import shutil
 import string
 import sys
 import tempfile
@@ -671,8 +672,7 @@ class BaseAuthTokenMiddlewareTest(testtools.TestCase):
 
         """
         conf = conf or self.conf
-        if 'http_handler' not in conf:
-            fake_http = fake_http or self.fake_http
+        if fake_http:
             conf['http_handler'] = fake_http
         fake_app = fake_app or self.fake_app
         self.middleware = auth_token.AuthProtocol(fake_app(expected_env), conf)
@@ -1002,6 +1002,21 @@ class AuthTokenMiddlewareTest(BaseAuthTokenMiddlewareTest):
         self.assertIsNotNone(self.middleware.LOG.msg)
         self.assertIsNotNone(self.middleware.LOG.debugmsg)
 
+    def test_request_no_token_http(self):
+        req = webob.Request.blank('/', environ={'REQUEST_METHOD': 'HEAD'})
+        conf = {
+            'auth_host': 'keystone.example.com',
+            'auth_port': 1234,
+            'auth_protocol': 'http',
+            'auth_admin_prefix': '/testadmin',
+        }
+        self.set_middleware(conf=conf)
+        body = self.middleware(req.environ, self.start_fake_response)
+        self.assertEqual(self.response_status, 401)
+        self.assertEqual(self.response_headers['WWW-Authenticate'],
+                         "Keystone uri='http://keystone.example.com:1234'")
+        self.assertEqual(body, [''])
+
     def test_request_blank_token(self):
         req = webob.Request.blank('/')
         req.headers['X-Auth-Token'] = ''
@@ -1197,6 +1212,34 @@ class AuthTokenMiddlewareTest(BaseAuthTokenMiddlewareTest):
                           datetime.timedelta(seconds=24))
 
 
+class CertDownloadMiddlewareTest(BaseAuthTokenMiddlewareTest):
+    def setUp(self):
+        super(CertDownloadMiddlewareTest, self).setUp()
+        self.base_dir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        shutil.rmtree(self.base_dir)
+        super(CertDownloadMiddlewareTest, self).tearDown()
+
+    # Usually we supply a signed_dir with pre-installed certificates,
+    # so invocation of /usr/bin/openssl succeeds. This time we give it
+    # an empty directory, so it fails.
+    def test_request_no_token_dummy(self):
+        cert_dir = os.path.join(self.base_dir, 'certs')
+        os.mkdir(cert_dir)
+        conf = {
+            'auth_host': 'keystone.example.com',
+            'auth_port': 1234,
+            'auth_protocol': 'http',
+            'auth_admin_prefix': '/testadmin',
+            'signing_dir': cert_dir,
+        }
+        self.set_middleware(fake_http=self.fake_http, conf=conf)
+        self.assertRaises(cms.subprocess.CalledProcessError,
+                          self.middleware.verify_signed_token,
+                          self.token_dict['signed_token_scoped'])
+
+
 class v2AuthTokenMiddlewareTest(BaseAuthTokenMiddlewareTest):
     """v2 token specific tests.