一开始neutron-server的启动
neutron/server/__init__.py
def _init_configuration():
# the configuration will be read into the cfg.CONF global data structure
config.init(sys.argv[1:])
config.setup_logging()
config.set_config_defaults()
if not cfg.CONF.config_file:
sys.exit(_("ERROR: Unable to find configuration file via the default"
" search paths (~/.neutron/, ~/, /etc/neutron/, /etc/) and"
" the '--config-file' option!"))
def boot_server(server_func):
_init_configuration()
try:
server_func()
except KeyboardInterrupt:
pass
except RuntimeError as e:
sys.exit(_("ERROR: %s") % e)
boot_server里，首先_init_configuration里，获取neutron-server启动参数，然后启动boot_server传入的参数
看真正boot_server的地方
neutron/cmd/eventlet/server/__init__.py
from neutron import server
from neutron.server import rpc_eventlet
from neutron.server import wsgi_eventlet
def main():
server.boot_server(wsgi_eventlet.eventlet_wsgi_server)
传入的参数即为boot_server执行的方法
neutron/server/wsgi_eventlet.py
def eventlet_wsgi_server():
neutron_api = service.serve_wsgi(service.NeutronApiService)
start_api_and_rpc_workers(neutron_api)
先看serve_wsgi方法
neutron/service.py
def serve_wsgi(cls):
try:
service = cls.create()
service.start()
except Exception:
with excutils.save_and_reraise_exception():
LOG.exception('Unrecoverable error: please check log '
'for details.')
registry.notify(resources.PROCESS, events.BEFORE_SPAWN, service)
return service
调用了传入类的create方法，创建一个服务，然后start这个服务
查看NeutronApiService
class NeutronApiService(WsgiService):
"""Class for neutron-api service."""
def __init__(self, app_name):
profiler.setup('neutron-server', cfg.CONF.host)
super(NeutronApiService, self).__init__(app_name)
@classmethod
def create(cls, app_name='neutron'):
# Setup logging early
config.setup_logging()
service = cls(app_name)
return service
从注释可以看出，这里封装了一个API功能的类，调用create方法，传入一个app_name
看基类WsgiService
class WsgiService(object):
"""Base class for WSGI based services.
For each api you define, you must also define these flags:
:<api>_listen: The address on which to listen
:<api>_listen_port: The port on which to listen
"""
def __init__(self, app_name):
self.app_name = app_name
self.wsgi_app = None
def start(self):
self.wsgi_app = _run_wsgi(self.app_name)
def wait(self):
self.wsgi_app.wait()
这里NeutronApiService继承WsgiService，并且参数app_name传了一个neutron，只表明NeutronApiService这个neutron服务是一个WSGI服务，create方法构造了这个服务，然后start方法运行了这个服务
def _run_wsgi(app_name):
app = config.load_paste_app(app_name)
if not app:
LOG.error('No known API applications configured.')
return
return run_wsgi_app(app)
调用load_paste_app加载这个服务
neutron/common/config.py
def load_paste_app(app_name):
"""Builds and returns a WSGI app from a paste config file.
:param app_name: Name of the application to load
"""
loader = wsgi.Loader(cfg.CONF)
app = loader.load_app(app_name)
return app
待续……
