Add API endpoint to query build information

This creates the '/<tenant_id>/build_info' endpoint and returns the build revision
as defined in the 'heat_revision' configuration option. This provides
both the revision of the engine and the api:

{
  "api": {
    "revision": <api revision>
  },
  "engine": {
    "revision": <engine revision>
  }
}

Implements: blueprint heat-build-info
Change-Id: Ibb2f5afda7c5d7c314e5e062d618405d9f4eb318

etc/heat/heat.conf.sample

@@ -983,3 +983,16 @@
 #insecure=false
 
 
+[revision]
+
+#
+# Options defined in heat.common.config
+#
+
+# Heat build revision. If you would prefer to manage your
+# build revision separately you can move this section to a
+# different file and add it as another config option (string
+# value)
+#heat_revision=unknown
+
+

heat/api/openstack/v1/__init__.py

@@ -19,6 +19,7 @@ from heat.api.openstack.v1 import stacks
 from heat.api.openstack.v1 import resources
 from heat.api.openstack.v1 import events
 from heat.api.openstack.v1 import actions
+from heat.api.openstack.v1 import build_info
 from heat.common import wsgi
 
 from heat.openstack.common import log as logging
@@ -36,8 +37,8 @@ class API(wsgi.Router):
         self.conf = conf
         mapper = routes.Mapper()
 
+        # Stacks
         stacks_resource = stacks.create_resource(conf)
-
         with mapper.submapper(controller=stacks_resource,
                               path_prefix="/{tenant_id}") as stack_mapper:
             # Template handling
@@ -164,4 +165,14 @@ class API(wsgi.Router):
                               action="action",
                               conditions={'method': 'POST'})
 
+        # Info
+        info_resource = build_info.create_resource(conf)
+        with mapper.submapper(controller=info_resource,
+                              path_prefix="/{tenant_id}") as info_mapper:
+
+            info_mapper.connect('build_info',
+                                '/build_info',
+                                action='build_info',
+                                conditions={'method': 'GET'})
+
         super(API, self).__init__(mapper)

heat/api/openstack/v1/build_info.py

@@ -0,0 +1,51 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#
+#    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.
+
+from oslo.config import cfg
+
+from heat.api.openstack.v1 import util
+from heat.common import wsgi
+from heat.rpc import client as rpc_client
+
+
+class BuildInfoController(object):
+    """
+    WSGI controller for BuildInfo in Heat v1 API
+    Returns build information for current app
+    """
+
+    def __init__(self, options):
+        self.options = options
+        self.engine = rpc_client.EngineClient()
+
+    @util.tenant_local
+    def build_info(self, req):
+        engine_revision = self.engine.get_revision(req.context)
+        build_info = {
+            'api': {'revision': cfg.CONF.revision['heat_revision']},
+            'engine': {'revision': engine_revision}
+        }
+
+        return build_info
+
+
+def create_resource(options):
+    """
+    BuildInfo factory method.
+    """
+    deserializer = wsgi.JSONRequestDeserializer()
+    serializer = wsgi.JSONResponseSerializer()
+    return wsgi.Resource(BuildInfoController(options), deserializer,
+                         serializer)

heat/common/config.py

@@ -150,6 +150,15 @@ def register_clients_opts():
         cfg.CONF.register_opts(opts_copy, group=client_specific_group)
 
 
+revision_group = cfg.OptGroup('revision')
+revision_opts = [
+    cfg.StrOpt('heat_revision',
+               default='unknown',
+               help=_('Heat build revision. '
+                      'If you would prefer to manage your build revision '
+                      'separately you can move this section to a different '
+                      'file and add it as another config option'))]
+
 cfg.CONF.register_opts(engine_opts)
 cfg.CONF.register_opts(service_opts)
 cfg.CONF.register_opts(rpc_opts)
@@ -157,6 +166,8 @@ cfg.CONF.register_group(paste_deploy_group)
 cfg.CONF.register_opts(paste_deploy_opts, group=paste_deploy_group)
 cfg.CONF.register_group(auth_password_group)
 cfg.CONF.register_opts(auth_password_opts, group=auth_password_group)
+cfg.CONF.register_group(revision_group)
+cfg.CONF.register_opts(revision_opts, group=revision_group)
 register_clients_opts()
 
 

heat/engine/service.py

@@ -196,6 +196,9 @@ class EngineService(service.Service):
 
         return [format_stack_detail(s) for s in stacks]
 
+    def get_revision(self, cnxt):
+        return cfg.CONF.revision['heat_revision']
+
     @request_context
     def list_stacks(self, cnxt, limit=None, marker=None, sort_keys=None,
                     sort_dir=None, filters=None):

heat/rpc/client.py

@@ -322,3 +322,6 @@ class EngineClient(heat.openstack.common.rpc.proxy.RpcProxy):
         return self.call(ctxt, self.make_msg('set_watch_state',
                                              watch_name=watch_name,
                                              state=state))
+
+    def get_revision(self, ctxt):
+        return self.call(ctxt, self.make_msg('get_revision'))

heat/tests/test_api_openstack_v1.py

@@ -33,6 +33,7 @@ import heat.api.openstack.v1.stacks as stacks
 import heat.api.openstack.v1.resources as resources
 import heat.api.openstack.v1.events as events
 import heat.api.openstack.v1.actions as actions
+import heat.api.openstack.v1.build_info as build_info
 from heat.tests import utils
 
 import heat.api.middleware.fault as fault
@@ -2432,6 +2433,16 @@ class RoutesTest(HeatTestCase):
                 'event_id': 'dddd'
             })
 
+    def test_build_info(self):
+        self.assertRoute(
+            self.m,
+            '/fake_tenant/build_info',
+            'GET',
+            'build_info',
+            'BuildInfoController',
+            {'tenant_id': 'fake_tenant'}
+        )
+
 
 class ActionControllerTest(ControllerTest, HeatTestCase):
     '''
@@ -2595,3 +2606,39 @@ class ActionControllerTest(ControllerTest, HeatTestCase):
                           stack_id=stack_identity.stack_id,
                           body=body)
         self.m.VerifyAll()
+
+
+class BuildInfoControllerTest(HeatTestCase):
+    def test_theres_a_default_api_build_revision(self):
+        req = mock.Mock()
+        controller = build_info.BuildInfoController({})
+        controller.engine = mock.Mock()
+
+        response = controller.build_info(req, tenant_id='tenant_id')
+        self.assertIn('api', response)
+        self.assertIn('revision', response['api'])
+        self.assertEqual('unknown', response['api']['revision'])
+
+    @mock.patch.object(build_info.cfg, 'CONF')
+    def test_response_api_build_revision_from_config_file(self, mock_conf):
+        req = mock.Mock()
+        controller = build_info.BuildInfoController({})
+        mock_engine = mock.Mock()
+        mock_engine.get_revision.return_value = 'engine_revision'
+        controller.engine = mock_engine
+        mock_conf.revision = {'heat_revision': 'test'}
+
+        response = controller.build_info(req, tenant_id='tenant_id')
+        self.assertEqual('test', response['api']['revision'])
+
+    def test_retrieves_build_revision_from_the_engine(self):
+        req = mock.Mock()
+        controller = build_info.BuildInfoController({})
+        mock_engine = mock.Mock()
+        mock_engine.get_revision.return_value = 'engine_revision'
+        controller.engine = mock_engine
+
+        response = controller.build_info(req, tenant_id='tenant_id')
+        self.assertIn('engine', response)
+        self.assertIn('revision', response['engine'])
+        self.assertEqual('engine_revision', response['engine']['revision'])