diff options
Diffstat (limited to 'nova')
| -rw-r--r-- | nova/api/__init__.py | 3 | ||||
| -rw-r--r-- | nova/manager.py | 34 | ||||
| -rw-r--r-- | nova/service.py | 6 | ||||
| -rw-r--r-- | nova/utils.py | 8 |
4 files changed, 49 insertions, 2 deletions
diff --git a/nova/api/__init__.py b/nova/api/__init__.py index f693225d9..1dabd3d21 100644 --- a/nova/api/__init__.py +++ b/nova/api/__init__.py @@ -30,6 +30,7 @@ import routes import webob.dec from nova import flags +from nova import utils from nova import wsgi from nova.api import cloudpipe from nova.api import ec2 @@ -83,6 +84,7 @@ class API(wsgi.Router): mapper.connect("/cloudpipe/{path_info:.*}", controller=cloudpipe.API()) super(API, self).__init__(mapper) + @utils.fix_wsgify_docstr @webob.dec.wsgify def osapi_versions(self, req): """Respond to a request for all OpenStack API versions.""" @@ -94,6 +96,7 @@ class API(wsgi.Router): "attributes": dict(version=["status", "id"])}} return wsgi.Serializer(req.environ, metadata).to_content_type(response) + @utils.fix_wsgify_docstr @webob.dec.wsgify def ec2api_versions(self, req): """Respond to a request for all EC2 versions.""" diff --git a/nova/manager.py b/nova/manager.py index 4244b2db4..a6efb8732 100644 --- a/nova/manager.py +++ b/nova/manager.py @@ -15,8 +15,40 @@ # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. + """ -Base class for managers of different parts of the system +Managers are responsible for a certain aspect of the sytem. It is a logical +grouping of code relating to a portion of the system. In general other +components should be using the manager to make changes to the components that +it is responsible for. + +For example, other components that need to deal with volumes in some way, +should do so by calling methods on the VolumeManager instead of directly +changing fields in the database. This allows us to keep all of the code +relating to volumes in the same place. + +We have adopted a basic strategy of Smart managers and dumb data, which means +rather than attaching methods to data objects, components should call manager +methods that act on the data. + +Methods on managers that can be executed locally should be called directly. If +a particular method must execute on a remote host, this should be done via rpc +to the service that wraps the manager + +Managers should be responsible for most of the db access, and +non-implementation specific data. Anything implementation specific that can't +be generalized should be done by the Driver. + +In general, we prefer to have one manager with multiple drivers for different +implementations, but sometimes it makes sense to have multiple managers. You +can think of it this way: Abstract different overall strategies at the manager +level(FlatNetwork vs VlanNetwork), and different implementations at the driver +level(LinuxNetDriver vs CiscoNetDriver). + +Managers will often provide methods for initial setup of a host or periodic +tasksto a wrapping service. + +This module provides Manager, a base class for managers. """ from nova import utils diff --git a/nova/service.py b/nova/service.py index d53d92b65..0eb3a2762 100644 --- a/nova/service.py +++ b/nova/service.py @@ -17,7 +17,11 @@ # under the License. """ -Generic Node baseclass for all workers that run on hosts +A service is a very thin wrapper around a Manager object. It exposes the +manager's public methods to other components of the system via rpc. It will +report state periodically to the database and is responsible for initiating any periodic tasts that need to be executed on a given host. + +This module contains Service, a generic baseclass for all workers. """ import inspect diff --git a/nova/utils.py b/nova/utils.py index e7892a212..d7ebe5b4c 100644 --- a/nova/utils.py +++ b/nova/utils.py @@ -21,6 +21,7 @@ System-level utilities and helper functions. """ import datetime +import functools import inspect import logging import os @@ -232,3 +233,10 @@ def utf8(value): return value.encode("utf-8") assert isinstance(value, str) return value + +def fix_wsgify_docstr(wsgified_func): + """A decorator to re-assign docstrings that webob.dec.wsgify clobbers.""" + @functools.wraps(wsgified_func.func) + def _f(*args, **kwargs): + wsgified_func(*args, **kwargs) + return _f |
