moving instance existance logic down to api layer

3 files changed, 45 insertions, 21 deletions

diff --git a/nova/api/openstack/server_metadata.py b/nova/api/openstack/server_metadata.py
index ec9e10496..8a314de22 100644
--- a/nova/api/openstack/server_metadata.py
+++ b/nova/api/openstack/server_metadata.py
@@ -43,36 +43,35 @@ class Controller(object):
             expl = _('No Request Body')
             raise exc.HTTPBadRequest(explanation=expl)
 
-    def _check_server_exists(self, context, server_id):
-        try:
-            self.compute_api.routing_get(context, server_id)
-        except exception.InstanceNotFound:
-            msg = _('Server does not exist')
-            raise exc.HTTPNotFound(explanation=msg)
-
     def index(self, req, server_id):
         """ Returns the list of metadata for a given instance """
         context = req.environ['nova.context']
-        self._check_server_exists(context, server_id)
-        return self._get_metadata(context, server_id)
+        try:
+            return self._get_metadata(context, server_id)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
 
     def create(self, req, server_id, body):
         self._check_body(body)
         context = req.environ['nova.context']
-        self._check_server_exists(context, server_id)
         metadata = body.get('metadata')
         try:
             self.compute_api.update_or_create_instance_metadata(context,
                                                                 server_id,
                                                                 metadata)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
+
         except quota.QuotaError as error:
             self._handle_quota_error(error)
+
         return body
 
     def update(self, req, server_id, id, body):
         self._check_body(body)
         context = req.environ['nova.context']
-        self._check_server_exists(context, server_id)
         if not id in body:
             expl = _('Request body and URI mismatch')
             raise exc.HTTPBadRequest(explanation=expl)
@@ -83,6 +82,10 @@ class Controller(object):
             self.compute_api.update_or_create_instance_metadata(context,
                                                                 server_id,
                                                                 body)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
+
         except quota.QuotaError as error:
             self._handle_quota_error(error)
 
@@ -91,18 +94,26 @@ class Controller(object):
     def show(self, req, server_id, id):
         """ Return a single metadata item """
         context = req.environ['nova.context']
-        self._check_server_exists(context, server_id)
-        data = self._get_metadata(context, server_id)
-        if id in data['metadata']:
+        try:
+            data = self._get_metadata(context, server_id)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
+
+        try:
             return {id: data['metadata'][id]}
-        else:
-            return faults.Fault(exc.HTTPNotFound())
+        except KeyError:
+            msg = _("metadata item %s was not found" % (id))
+            raise exc.HTTPNotFound(explanation=msg)
 
     def delete(self, req, server_id, id):
         """ Deletes an existing metadata """
         context = req.environ['nova.context']
-        self._check_server_exists(context, server_id)
-        self.compute_api.delete_instance_metadata(context, server_id, id)
+        try:
+            self.compute_api.delete_instance_metadata(context, server_id, id)
+        except exception.InstanceNotFound:
+            msg = _('Server %(server_id)s does not exist') % locals()
+            raise exc.HTTPNotFound(explanation=msg)
 
     def _handle_quota_error(self, error):
         """Reraise quota errors as api-specific http exceptions."""
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 73870d2f3..7cea3ba70 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -18,7 +18,7 @@
 """
 Implementation of SQLAlchemy backend.
 """
-
+import traceback
 import warnings
 
 from nova import db
@@ -2609,7 +2609,17 @@ def zone_get_all(context):
 
 ####################
 
+
+def require_instance_exists(func):
+    def new_func(context, instance_id, *args, **kwargs):
+        db.api.instance_get(context, instance_id)
+        return func(context, instance_id, *args, **kwargs)
+    new_func.__name__ = func.__name__
+    return new_func
+
+
 @require_context
+@require_instance_exists
 def instance_metadata_get(context, instance_id):
     session = get_session()
 
@@ -2625,6 +2635,7 @@ def instance_metadata_get(context, instance_id):
 
 
 @require_context
+@require_instance_exists
 def instance_metadata_delete(context, instance_id, key):
     session = get_session()
     session.query(models.InstanceMetadata).\
@@ -2637,6 +2648,7 @@ def instance_metadata_delete(context, instance_id, key):
 
 
 @require_context
+@require_instance_exists
 def instance_metadata_delete_all(context, instance_id):
     session = get_session()
     session.query(models.InstanceMetadata).\
@@ -2648,6 +2660,7 @@ def instance_metadata_delete_all(context, instance_id):
 
 
 @require_context
+@require_instance_exists
 def instance_metadata_get_item(context, instance_id, key):
     session = get_session()
 
@@ -2664,6 +2677,7 @@ def instance_metadata_get_item(context, instance_id, key):
 
 
 @require_context
+@require_instance_exists
 def instance_metadata_update_or_create(context, instance_id, metadata):
     session = get_session()
 
diff --git a/nova/tests/api/openstack/test_server_metadata.py b/nova/tests/api/openstack/test_server_metadata.py
index 8c7b48fed..0431e68d2 100644
--- a/nova/tests/api/openstack/test_server_metadata.py
+++ b/nova/tests/api/openstack/test_server_metadata.py
@@ -144,7 +144,6 @@ class ServerMetaDataTest(unittest.TestCase):
         req = webob.Request.blank('/v1.1/servers/1/meta/key6')
         req.environ['api.version'] = '1.1'
         res = req.get_response(fakes.wsgi_app())
-        res_dict = json.loads(res.body)
         self.assertEqual(404, res.status_int)
 
     def test_delete(self):
@@ -173,8 +172,8 @@ class ServerMetaDataTest(unittest.TestCase):
         req.body = '{"metadata": {"key1": "value1"}}'
         req.headers["content-type"] = "application/json"
         res = req.get_response(fakes.wsgi_app())
-        res_dict = json.loads(res.body)
         self.assertEqual(200, res.status_int)
+        res_dict = json.loads(res.body)
         self.assertEqual('application/json', res.headers['Content-Type'])
         self.assertEqual('value1', res_dict['metadata']['key1'])