整个 web 服务入口
cmd 启动 cinder-volume-api 的 时候 /root/cinder/cinder/cmd/api.py
def main():
.....
server = service.WSGIService('osapi_volume')
.....
创建 WsgiServer 的代码 片段
默认 conf 中存在 osapi_volume_listen, osapi_volume_listen_port
# IP address on which OpenStack Volume API listens (string value)
#osapi_volume_listen = 0.0.0.0
# Port on which OpenStack Volume API listens (port value)
# Minimum value: 0
# Maximum value: 65535
#osapi_volume_listen_port = 8776
class WSGIService(service.ServiceBase):
"""Provides ability to launch API from a 'paste' configuration."""
def __init__(self, name, loader=None):
"""Initialize, but do not start the WSGI server.
:param name: The name of the WSGI server given to the loader.
:param loader: Loads the WSGI application using the given name.
:returns: None
"""
self.name = name
self.manager = self._get_manager()
self.loader = loader or wsgi.Loader(CONF)
self.app = self.loader.load_app(name)
self.host = getattr(CONF, '%s_listen' % name, "0.0.0.0")
self.port = getattr(CONF, '%s_listen_port' % name, 0)
self.workers = (getattr(CONF, '%s_workers' % name, None) or
processutils.get_worker_count())
if self.workers and self.workers < 1:
worker_name = '%s_workers' % name
msg = (_("%(worker_name)s value of %(workers)d is invalid, "
"must be greater than 0.") %
{'worker_name': worker_name,
'workers': self.workers})
raise exception.InvalidInput(msg)
setup_profiler(name, self.host)
self.server = wsgi.Server(CONF,
name,
self.app,
host=self.host,
port=self.port)
paste 配置文件
./cinder/etc/cinder/api-paste.ini 按照 paste 书写了 composite, filter, app, pipeline
[composite:osapi_volume]
use = call:cinder.api:root_app_factory
/: apiversions
- 位于 cinder/api.py 中的 root_app_factory 方法
def root_app_factory(loader, global_conf, **local_conf):
if CONF.enable_v1_api:
LOG.warning(_LW('The v1 api is deprecated and is not under active '
'development. You should set enable_v1_api=false '
'and enable_v3_api=true in your cinder.conf file.'))
return paste.urlmap.urlmap_factory(loader, global_conf, **local_conf)
- 再继续 查找 apiversion
[pipeline:apiversions]
pipeline = cors http_proxy_to_wsgi faultwrap osvolumeversionapp
- 再继续查找 osvolumeversionapp
[app:osvolumeversionapp]
paste.app_factory = cinder.api.versions:Versions.factory
- 再继续 查找 cinder.api.versions:Versions.factory
其中 mapper 的 action 参数 负责调用 resource( 一个 controller 类 ) 中 同名的 方法
class Versions(openstack.APIRouter):
"""Route versions requests."""
ExtensionManager = extensions.ExtensionManager
def _setup_routes(self, mapper, ext_mgr):
self.resources['versions'] = create_resource()
mapper.connect('versions', '/',
controller=self.resources['versions'],
action='all')
mapper.redirect('', '/')
- 但是 Versions 类中 没有 factory 方法，那么 继续 去查找 他的 父类
class APIRouter(base_wsgi.Router):
"""Routes requests on the API to the appropriate controller and method."""
ExtensionManager = None # override in subclasses
@classmethod
def factory(cls, global_config, **local_config):
"""Simple paste factory, :class:`cinder.wsgi.Router` doesn't have."""
return cls()
省略 一些代码 .....
- 找到了 工厂factory 方法，我们 就继续 回到 工厂 返回的 Versions 类
action='all' 绑定到了 create_resource() 返回的 controller 类
def create_resource():
return wsgi.Resource(VersionsController())
再去查看 VersionController 类的定义 ./cinder/cinder/api/versions.py
class VersionsController(wsgi.Controller):
def __init__(self):
super(VersionsController, self).__init__(None)
省略一些代码...
@wsgi.response(300)
def all(self, req):
"""Return all known versions."""
builder = views_versions.get_view_builder(req)
known_versions = copy.deepcopy(_KNOWN_VERSIONS)
return builder.build_versions(known_versions)
所以 在浏览器 输入
http://volume_api_ip:8776/
就会 被 转到 versionapp 的 all 方法, 最后 实际调用就是
builder.build_versions(known_versions) 返回一个 可以被 json 的字典。
view 视图文件 ./cinder/cinder/api/views/versions.py
class ViewBuilder(object):
def __init__(self, base_url):
"""Initialize ViewBuilder.
:param base_url: url of the root wsgi application
"""
self.base_url = base_url
def build_versions(self, versions):
views = [self._build_version(versions[key])
for key in sorted(list(versions.keys()))]
return dict(versions=views)
