Server support for display snapshot of zun stats

This patch adds support for display snapshot of zun stats at
server side.

Implements: blueprint support-stats-snapshot

Change-Id: Id82a4f9f7b9e32d202852083da5714e42751fe98

etc/zun/policy.json

@@ -26,6 +26,7 @@
     "container:top": "rule:admin_or_user",
     "container:get_archive": "rule:admin_or_user",
     "container:put_archive": "rule:admin_or_user",
+    "container:stats": "rule:admin_or_user",
 
     "image:pull": "rule:default",
     "image:get_all": "rule:default",

zun/api/controllers/v1/containers.py

@@ -93,6 +93,7 @@ class ContainersController(base.Controller):
         'top': ['GET'],
         'get_archive': ['GET'],
         'put_archive': ['POST'],
+        'stats': ['GET'],
     }
 
     @pecan.expose('json')
@@ -528,3 +529,15 @@ class ContainersController(base.Controller):
         compute_api = pecan.request.compute_api
         compute_api.container_put_archive(context, container,
                                           kw['path'], kw['data'])
+
+    @pecan.expose('json')
+    @exception.wrap_pecan_controller_exception
+    def stats(self, container_id):
+        container = _get_container(container_id)
+        check_policy_on_container(container.as_dict(), "container:stats")
+        utils.validate_container_state(container, 'stats')
+        LOG.debug('Calling compute.container_stats with %s'
+                  % (container.uuid))
+        context = pecan.request.context
+        compute_api = pecan.request.compute_api
+        return compute_api.container_stats(context, container)

zun/common/utils.py

@@ -57,6 +57,7 @@ VALID_STATES = {
                     consts.STOPPED],
     'logs': [consts.CREATED, consts.ERROR, consts.PAUSED, consts.RUNNING,
              consts.STOPPED, consts.UNKNOWN],
+    'stats': [consts.RUNNING],
 }
 
 

zun/compute/api.py

@@ -109,6 +109,9 @@ class API(object):
     def container_put_archive(self, context, container, *args):
         return self.rpcapi.container_put_archive(context, container, *args)
 
+    def container_stats(self, context, container):
+        return self.rpcapi.container_stats(context, container)
+
     def image_pull(self, context, image, *args):
         return self.rpcapi.image_pull(context, image, *args)
 

zun/compute/manager.py

@@ -462,6 +462,19 @@ class Manager(object):
             LOG.exception("Unexpected exception: %s", six.text_type(e))
             raise
 
+    @translate_exception
+    def container_stats(self, context, container):
+        LOG.debug('Displaying stats of the container: %s', container.uuid)
+        try:
+            return self.driver.stats(container)
+        except exception.DockerError as e:
+            LOG.error("Error occurred while calling Docker stats API: %s",
+                      six.text_type(e))
+            raise
+        except Exception as e:
+            LOG.exception("Unexpected exception: %s", six.text_type(e))
+            raise
+
     def image_pull(self, context, image):
         utils.spawn_n(self._do_image_pull, context, image)
 

zun/compute/rpcapi.py

@@ -141,6 +141,11 @@ class API(rpc_service.API):
         return self._call(container.host, 'container_put_archive',
                           container=container, path=path, data=data)
 
+    @check_container_host
+    def container_stats(self, context, container):
+        return self._call(container.host, 'container_stats',
+                          container=container)
+
     def image_pull(self, context, image):
         # NOTE(hongbin): Image API doesn't support multiple compute nodes
         # scenario yet, so we temporarily set host to None and rpc will

zun/container/docker/driver.py

@@ -463,6 +463,12 @@ class DockerDriver(driver.ContainerDriver):
         with docker_utils.docker_client() as docker:
             docker.put_archive(container.container_id, path, data)
 
+    @check_container_id
+    def stats(self, container):
+        with docker_utils.docker_client() as docker:
+            return docker.stats(container.container_id, decode=False,
+                                stream=False)
+
     def _encode_utf8(self, value):
         if six.PY2 and not isinstance(value, unicode):
             value = unicode(value)

zun/container/driver.py

@@ -141,6 +141,10 @@ class ContainerDriver(object):
         """copy resource to a container."""
         raise NotImplementedError()
 
+    def stats(self, container):
+        """Display stats of the container(s)."""
+        raise NotImplementedError()
+
     def create_sandbox(self, context, container, **kwargs):
         """Create a sandbox."""
         raise NotImplementedError()

zun/tests/unit/api/controllers/v1/test_containers.py

@@ -1197,6 +1197,23 @@ class TestContainerController(api_base.FunctionalTest):
             self.app.post('/v1/containers/%s/%s/' % (test_object.uuid,
                                                      'put_archive'))
 
+    @patch('zun.common.utils.validate_container_state')
+    @patch('zun.compute.api.API.container_stats')
+    @patch('zun.objects.Container.get_by_uuid')
+    def test_stats_container_by_uuid(self, mock_get_by_uuid,
+                                     mock_container_stats, mock_validate):
+        mock_container_stats.return_value = ""
+        test_container = utils.get_test_container()
+        test_container_obj = objects.Container(self.context, **test_container)
+        mock_get_by_uuid.return_value = test_container_obj
+
+        container_uuid = test_container.get('uuid')
+        url = '/v1/containers/%s/stats'\
+              % container_uuid
+        response = self.app.get(url)
+        self.assertEqual(200, response.status_int)
+        self.assertTrue(mock_container_stats.called)
+
 
 class TestContainerEnforcement(api_base.FunctionalTest):