placement: skip authentication on root URI

The placement API GET / is for version discovery. Skip authentication
on this URL.

The change to test_deploy is required to make it request a URL that
requires authentication. It had been using /.

Change-Id: I5ed1f7a607620c43671e90eaf8a1f6285f1d15e4
Closes-Bug: #1733630

nova/api/openstack/placement/auth.py

@@ -11,6 +11,7 @@
 #    under the License.
 
 
+from keystonemiddleware import auth_token
 from oslo_context import context
 from oslo_db.sqlalchemy import enginefacade
 from oslo_log import log as logging
@@ -37,6 +38,9 @@ class NoAuthMiddleware(Middleware):
 
     @webob.dec.wsgify
     def __call__(self, req):
+        if req.environ['PATH_INFO'] == '/':
+            return self.application
+
         if 'X-Auth-Token' not in req.headers:
             return webob.exc.HTTPUnauthorized()
 
@@ -68,9 +72,37 @@ class PlacementKeystoneContext(Middleware):
         ctx = RequestContext.from_environ(
             req.environ, request_id=req_id)
 
-        if ctx.user_id is None:
+        if ctx.user_id is None and req.environ['PATH_INFO'] != '/':
             LOG.debug("Neither X_USER_ID nor X_USER found in request")
             return webob.exc.HTTPUnauthorized()
 
         req.environ['placement.context'] = ctx
         return self.application
+
+
+class PlacementAuthProtocol(auth_token.AuthProtocol):
+    """A wrapper on Keystone auth_token middleware.
+
+    Does not perform verification of authentication tokens
+    for root in the API.
+
+    """
+    def __init__(self, app, conf):
+        self._placement_app = app
+        super(PlacementAuthProtocol, self).__init__(app, conf)
+
+    def __call__(self, environ, start_response):
+        if environ['PATH_INFO'] == '/':
+            return self._placement_app(environ, start_response)
+
+        return super(PlacementAuthProtocol, self).__call__(
+            environ, start_response)
+
+
+def filter_factory(global_conf, **local_conf):
+    conf = global_conf.copy()
+    conf.update(local_conf)
+
+    def auth_filter(app):
+        return PlacementAuthProtocol(app, conf)
+    return auth_filter

nova/api/openstack/placement/deploy.py

@@ -11,7 +11,6 @@
 #    under the License.
 """Deployment handling for Placmenent API."""
 
-from keystonemiddleware import auth_token
 import oslo_middleware
 from oslo_middleware import cors
 
@@ -41,7 +40,7 @@ def deploy(conf, project_name):
         # Do not use 'oslo_config_project' param here as the conf
         # location may have been overridden earlier in the deployment
         # process with OS_PLACEMENT_CONFIG_DIR in wsgi.py.
-        auth_middleware = auth_token.filter_factory(
+        auth_middleware = auth.filter_factory(
             {}, oslo_config_config=conf)
 
     # Pass in our CORS config, if any, manually as that's a)

nova/tests/functional/api/openstack/placement/gabbits/confirm-auth.yaml

@@ -11,12 +11,22 @@ defaults:
         accept: application/json
 
 tests:
-    - name: no token gets 401
+    - name: no token gets 200 at root
       GET: /
-      status: 401
+      status: 200
 
-    - name: with token 200
+    - name: with token 200 at root
       GET: /
       request_headers:
           x-auth-token: admin:admin
       status: 200
+
+    - name: no token gets 401
+      GET: /resource_providers
+      status: 401
+
+    - name: with token 200
+      GET: /resource_providers
+      request_headers:
+          x-auth-token: admin:admin
+      status: 200

nova/tests/unit/api/openstack/placement/test_deploy.py

@@ -35,7 +35,7 @@ class DeployTest(test.NoDBTestCase):
         # ensure that the auth_token middleware is chosen
         self.flags(auth_strategy='keystone', group='api')
         app = deploy.deploy(CONF, 'nova')
-        req = webob.Request.blank('/', method="GET")
+        req = webob.Request.blank('/resource_providers', method="GET")
 
         response = req.get_response(app)