# Copyright 2010 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # Copyright 2010 OpenStack LLC. # All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. """Utility methods for working with WSGI servers.""" from __future__ import print_function import errno import os import socket import ssl import sys import time import eventlet import eventlet.wsgi import greenlet from oslo_config import cfg from oslo_log import log from oslo_utils import netutils from paste import deploy import routes.middleware import six import webob.dec import webob.exc from manila import exception from manila.i18n import _ from manila.i18n import _LI socket_opts = [ cfg.IntOpt('backlog', default=4096, help="Number of backlog requests to configure the socket " "with."), cfg.BoolOpt('tcp_keepalive', default=True, help="Sets the value of TCP_KEEPALIVE (True/False) for each " "server socket."), cfg.IntOpt('tcp_keepidle', default=600, help="Sets the value of TCP_KEEPIDLE in seconds for each " "server socket. Not supported on OS X."), cfg.IntOpt('tcp_keepalive_interval', help="Sets the value of TCP_KEEPINTVL in seconds for each " "server socket. Not supported on OS X."), cfg.IntOpt('tcp_keepalive_count', help="Sets the value of TCP_KEEPCNT for each " "server socket. Not supported on OS X."), cfg.StrOpt('ssl_ca_file', default=None, help="CA certificate file to use to verify " "connecting clients."), cfg.StrOpt('ssl_cert_file', default=None, help="Certificate file to use when starting " "the server securely."), cfg.StrOpt('ssl_key_file', default=None, help="Private key file to use when starting " "the server securely."), ] eventlet_opts = [ cfg.IntOpt('max_header_line', default=16384, help="Maximum line size of message headers to be accepted. " "Option max_header_line may need to be increased when " "using large tokens (typically those generated by the " "Keystone v3 API with big service catalogs)."), ] CONF = cfg.CONF CONF.register_opts(socket_opts) CONF.register_opts(eventlet_opts) LOG = log.getLogger(__name__) class Server(object): """Server class to manage a WSGI server, serving a WSGI application.""" default_pool_size = 1000 def __init__(self, name, app, host=None, port=None, pool_size=None, protocol=eventlet.wsgi.HttpProtocol): """Initialize, but do not start, a WSGI server. :param name: Pretty name for logging. :param app: The WSGI application to serve. :param host: IP address to serve the application. :param port: Port number to server the application. :param pool_size: Maximum number of eventlets to spawn concurrently. :returns: None """ eventlet.wsgi.MAX_HEADER_LINE = CONF.max_header_line self.name = name self.app = app self._host = host or "0.0.0.0" self._port = port or 0 self._server = None self._socket = None self._protocol = protocol self._pool = eventlet.GreenPool(pool_size or self.default_pool_size) self._logger = log.getLogger("eventlet.wsgi.server") def _get_socket(self, host, port, backlog): bind_addr = (host, port) # TODO(dims): eventlet's green dns/socket module does not actually # support IPv6 in getaddrinfo(). We need to get around this in the # future or monitor upstream for a fix try: info = socket.getaddrinfo(bind_addr[0], bind_addr[1], socket.AF_UNSPEC, socket.SOCK_STREAM)[0] family = info[0] bind_addr = info[-1] except Exception: family = socket.AF_INET cert_file = CONF.ssl_cert_file key_file = CONF.ssl_key_file ca_file = CONF.ssl_ca_file use_ssl = cert_file or key_file if cert_file and not os.path.exists(cert_file): raise RuntimeError(_("Unable to find cert_file : %s") % cert_file) if ca_file and not os.path.exists(ca_file): raise RuntimeError(_("Unable to find ca_file : %s") % ca_file) if key_file and not os.path.exists(key_file): raise RuntimeError(_("Unable to find key_file : %s") % key_file) if use_ssl and (not cert_file or not key_file): raise RuntimeError(_("When running server in SSL mode, you must " "specify both a cert_file and key_file " "option value in your configuration file")) def wrap_ssl(sock): ssl_kwargs = { 'server_side': True, 'certfile': cert_file, 'keyfile': key_file, 'cert_reqs': ssl.CERT_NONE, } if CONF.ssl_ca_file: ssl_kwargs['ca_certs'] = ca_file ssl_kwargs['cert_reqs'] = ssl.CERT_REQUIRED return ssl.wrap_socket(sock, **ssl_kwargs) sock = None retry_until = time.time() + 30 while not sock and time.time() < retry_until: try: sock = eventlet.listen(bind_addr, backlog=backlog, family=family) if use_ssl: sock = wrap_ssl(sock) except socket.error as err: if err.args[0] != errno.EADDRINUSE: raise eventlet.sleep(0.1) if not sock: raise RuntimeError(_("Could not bind to %(host)s:%(port)s " "after trying for 30 seconds") % {'host': host, 'port': port}) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) # sockets can hang around forever without keepalive netutils.set_tcp_keepalive(sock, CONF.tcp_keepalive, CONF.tcp_keepidle, CONF.tcp_keepalive_interval, CONF.tcp_keepalive_count) return sock def _start(self): """Run the blocking eventlet WSGI server. :returns: None """ eventlet.wsgi.server(self._socket, self.app, protocol=self._protocol, custom_pool=self._pool, log=self._logger) def start(self, backlog=128): """Start serving a WSGI application. :param backlog: Maximum number of queued connections. :returns: None :raises: manila.exception.InvalidInput """ if backlog < 1: raise exception.InvalidInput( reason='The backlog must be more than 1') self._socket = self._get_socket(self._host, self._port, backlog=backlog) self._server = eventlet.spawn(self._start) (self._host, self._port) = self._socket.getsockname()[0:2] LOG.info(_LI("Started %(name)s on %(_host)s:%(_port)s"), {'name': self.name, '_host': self._host, '_port': self._port}) @property def host(self): return self._host @property def port(self): return self._port def stop(self): """Stop this server. This is not a very nice action, as currently the method by which a server is stopped is by killing its eventlet. :returns: None """ LOG.info(_LI("Stopping WSGI server.")) self._server.kill() def wait(self): """Block, until the server has stopped. Waits on the server's eventlet to finish, then returns. :returns: None """ try: self._server.wait() except greenlet.GreenletExit: LOG.info(_LI("WSGI server has stopped.")) class Request(webob.Request): pass class Application(object): """Base WSGI application wrapper. Subclasses need to implement __call__.""" @classmethod def factory(cls, global_config, **local_config): """Used for paste app factories in paste.deploy config files. Any local configuration (that is, values under the [app:APPNAME] section of the paste config) will be passed into the `__init__` method as kwargs. A hypothetical configuration would look like: [app:wadl] latest_version = 1.3 paste.app_factory = manila.api.fancy_api:Wadl.factory which would result in a call to the `Wadl` class as import manila.api.fancy_api fancy_api.Wadl(latest_version='1.3') You could of course re-implement the `factory` method in subclasses, but using the kwarg passing it shouldn't be necessary. """ return cls(**local_config) def __call__(self, environ, start_response): r"""Subclasses will probably want to implement __call__ like this: @webob.dec.wsgify(RequestClass=Request) def __call__(self, req): # Any of the following objects work as responses: # Option 1: simple string res = 'message\n' # Option 2: a nicely formatted HTTP exception page res = exc.HTTPForbidden(detail='Nice try') # Option 3: a webob Response object (in case you need to play with # headers, or you want to be treated like an iterable, or or or) res = Response(); res.app_iter = open('somefile') # Option 4: any wsgi app to be run next res = self.application # Option 5: you can get a Response object for a wsgi app, too, to # play with headers etc res = req.get_response(self.application) # You can then just return your response... return res # ... or set req.response and return None. req.response = res See the end of http://pythonpaste.org/webob/modules/dec.html for more info. """ raise NotImplementedError(_('You must implement __call__')) class Middleware(Application): """Base WSGI middleware. These classes require an application to be initialized that will be called next. By default the middleware will simply call its wrapped app, or you can override __call__ to customize its behavior. """ @classmethod def factory(cls, global_config, **local_config): """Used for paste app factories in paste.deploy config files. Any local configuration (that is, values under the [filter:APPNAME] section of the paste config) will be passed into the `__init__` method as kwargs. A hypothetical configuration would look like: [filter:analytics] redis_host = 127.0.0.1 paste.filter_factory = manila.api.analytics:Analytics.factory which would result in a call to the `Analytics` class as import manila.api.analytics analytics.Analytics(app_from_paste, redis_host='127.0.0.1') You could of course re-implement the `factory` method in subclasses, but using the kwarg passing it shouldn't be necessary. """ def _factory(app): return cls(app, **local_config) return _factory def __init__(self, application): self.application = application def process_request(self, req): """Called on each request. If this returns None, the next application down the stack will be executed. If it returns a response then that response will be returned and execution will stop here. """ return None def process_response(self, response): """Do whatever you'd like to the response.""" return response @webob.dec.wsgify(RequestClass=Request) def __call__(self, req): response = self.process_request(req) if response: return response response = req.get_response(self.application) return self.process_response(response) class Debug(Middleware): """Helper class for debugging a WSGI application. Can be inserted into any WSGI application chain to get information about the request and response. """ @webob.dec.wsgify(RequestClass=Request) def __call__(self, req): print(('*' * 40) + ' REQUEST ENVIRON') for key, value in req.environ.items(): print(key, '=', value) print() resp = req.get_response(self.application) print(('*' * 40) + ' RESPONSE HEADERS') for (key, value) in six.iteritems(resp.headers): print(key, '=', value) print() resp.app_iter = self.print_generator(resp.app_iter) return resp @staticmethod def print_generator(app_iter): """Iterator that prints the contents of a wrapper string.""" print(('*' * 40) + ' BODY') for part in app_iter: sys.stdout.write(part) sys.stdout.flush() yield part print() class Router(object): """WSGI middleware that maps incoming requests to WSGI apps.""" def __init__(self, mapper): """Create a router for the given routes.Mapper. Each route in `mapper` must specify a 'controller', which is a WSGI app to call. You'll probably want to specify an 'action' as well and have your controller be an object that can route the request to the action-specific method. Examples: mapper = routes.Mapper() sc = ServerController() # Explicit mapping of one route to a controller+action mapper.connect(None, '/svrlist', controller=sc, action='list') # Actions are all implicitly defined mapper.resource('server', 'servers', controller=sc) # Pointing to an arbitrary WSGI app. You can specify the # {path_info:.*} parameter so the target app can be handed just that # section of the URL. mapper.connect(None, '/v1.0/{path_info:.*}', controller=BlogApp()) """ self.map = mapper self._router = routes.middleware.RoutesMiddleware(self._dispatch, self.map) @webob.dec.wsgify(RequestClass=Request) def __call__(self, req): """Route the incoming request to a controller based on self.map. If no match, return a 404. """ return self._router @staticmethod @webob.dec.wsgify(RequestClass=Request) def _dispatch(req): """Dispatch the request to the appropriate controller. Called by self._router after matching the incoming request to a route and putting the information into req.environ. Either returns 404 or the routed WSGI app's response. """ match = req.environ['wsgiorg.routing_args'][1] if not match: return webob.exc.HTTPNotFound() app = match['controller'] return app class Loader(object): """Used to load WSGI applications from paste configurations.""" def __init__(self, config_path=None): """Initialize the loader, and attempt to find the config. :param config_path: Full or relative path to the paste config. :returns: None """ config_path = config_path or CONF.api_paste_config self.config_path = CONF.find_file(config_path) if not self.config_path: raise exception.ConfigNotFound(path=config_path) def load_app(self, name): """Return the paste URLMap wrapped WSGI application. :param name: Name of the application to load. :returns: Paste URLMap object wrapping the requested application. :raises: `manila.exception.PasteAppNotFound` """ try: return deploy.loadapp("config:%s" % self.config_path, name=name) except LookupError as err: LOG.error(err) raise exception.PasteAppNotFound(name=name, path=self.config_path)