WARN and use defaults when no policy file is found

Rather than refuse to start, it's nicer to use a sane set of default
policies when no policy file is found.

Fixes bug 1043482

Change-Id: I849737c61c0266952d931395fbc2ad3745c46f6e

glance/api/policy.py

@@ -28,7 +28,7 @@ from glance.openstack.common import policy
 LOG = logging.getLogger(__name__)
 
 policy_opts = (
-    cfg.StrOpt('policy_file', default=None),
+    cfg.StrOpt('policy_file', default='policy.json'),
     cfg.StrOpt('policy_default_rule', default='default'),
     )
 
@@ -36,6 +36,12 @@ CONF = cfg.CONF
 CONF.register_opts(policy_opts)
 
 
+DEFAULT_RULES = {
+    'default': [[]],
+    'manage_image_cache': [['role:admin']]
+}
+
+
 class Enforcer(object):
     """Responsible for loading and enforcing rules"""
 
@@ -52,20 +58,23 @@ class Enforcer(object):
 
     def load_rules(self):
         """Set the rules found in the json file on disk"""
-        rules = self._read_policy_file()
+        if self.policy_path:
+            rules = self._read_policy_file()
+            LOG.debug(_('Loaded policy rules: %s') % rules)
+        else:
+            rules = DEFAULT_RULES
+            LOG.debug(_('Using default policy rules: %s') % rules)
         self.set_rules(rules)
 
     @staticmethod
     def _find_policy_file():
         """Locate the policy json data file"""
-        if CONF.policy_file:
-            return CONF.policy_file
-
-        policy_file = CONF.find_file('policy.json')
-        if not policy_file:
-            raise cfg.ConfigFilesNotFoundError(('policy.json',))
-
-        return policy_file
+        policy_file = CONF.find_file(CONF.policy_file)
+        if policy_file:
+            return policy_file
+        else:
+            LOG.warn(_('Unable to find policy file'))
+            return None
 
     def _read_policy_file(self):
         """Read contents of the policy file

glance/tests/unit/test_clients.py

@@ -21,6 +21,7 @@ import tempfile
 
 from glance import client
 from glance.common import client as base_client
+from glance.common import config
 from glance.common import exception
 from glance.common import utils
 from glance import context
@@ -37,6 +38,9 @@ _gen_uuid = utils.generate_uuid
 UUID1 = _gen_uuid()
 UUID2 = _gen_uuid()
 
+#NOTE(bcwaldon): needed to init config_dir cli opt
+config.parse_args()
+
 
 class TestBadClients(test_utils.BaseTestCase):
 

glance/tests/unit/test_policy.py

@@ -0,0 +1,79 @@
+# Copyright 2012 OpenStack, LLC
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the 'License'); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an 'AS IS' BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import os.path
+
+import glance.api.policy
+from glance.common import exception
+import glance.context
+from glance.tests import utils as test_utils
+from glance.tests.unit import base
+
+
+class TestPolicyEnforcer(base.IsolatedUnitTest):
+    def test_policy_file_default_rules_default_location(self):
+        enforcer = glance.api.policy.Enforcer()
+
+        context = glance.context.RequestContext(roles=[])
+        enforcer.enforce(context, 'get_image', {})
+
+    def test_policy_file_custom_rules_default_location(self):
+        rules = {"get_image": [["false:false"]]}
+        self.set_policy_rules(rules)
+
+        enforcer = glance.api.policy.Enforcer()
+
+        context = glance.context.RequestContext(roles=[])
+        self.assertRaises(exception.Forbidden,
+                          enforcer.enforce, context, 'get_image', {})
+
+    def test_policy_file_custom_location(self):
+        self.config(policy_file=os.path.join(self.test_dir, 'gobble.gobble'))
+
+        rules = {"get_image": [["false:false"]]}
+        self.set_policy_rules(rules)
+
+        enforcer = glance.api.policy.Enforcer()
+
+        context = glance.context.RequestContext(roles=[])
+        self.assertRaises(exception.Forbidden,
+                          enforcer.enforce, context, 'get_image', {})
+
+
+class TestPolicyEnforcerNoFile(test_utils.BaseTestCase):
+    def test_policy_file_specified_but_not_found(self):
+        """Missing defined policy file should result in a default ruleset"""
+        self.config(policy_file='gobble.gobble')
+        enforcer = glance.api.policy.Enforcer()
+
+        context = glance.context.RequestContext(roles=[])
+        enforcer.enforce(context, 'get_image', {})
+        self.assertRaises(exception.Forbidden,
+                          enforcer.enforce, context, 'manage_image_cache', {})
+
+        admin_context = glance.context.RequestContext(roles=['admin'])
+        enforcer.enforce(admin_context, 'manage_image_cache', {})
+
+    def test_policy_file_default_not_found(self):
+        """Missing default policy file should result in a default ruleset"""
+        enforcer = glance.api.policy.Enforcer()
+
+        context = glance.context.RequestContext(roles=[])
+        enforcer.enforce(context, 'get_image', {})
+        self.assertRaises(exception.Forbidden,
+                          enforcer.enforce, context, 'manage_image_cache', {})
+
+        admin_context = glance.context.RequestContext(roles=['admin'])
+        enforcer.enforce(admin_context, 'manage_image_cache', {})

glance/tests/utils.py

@@ -28,7 +28,6 @@ import unittest
 
 import nose.plugins.skip
 
-# NOTE(ameade): this import is necessary so that common cfg opts are registered
 from glance.common import config
 from glance.common import utils
 from glance.common import wsgi
@@ -55,6 +54,11 @@ class BaseTestCase(unittest.TestCase):
     def setUp(self):
         super(BaseTestCase, self).setUp()
 
+        #NOTE(bcwaldon): parse_args has to be called to register certain
+        # command-line options - specifically we need config_dir for
+        # the following policy tests
+        config.parse_args()
+
     def tearDown(self):
         super(BaseTestCase, self).tearDown()
         CONF.reset()