# Copyright 2010 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # Copyright 2010 OpenStack Foundation # 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 os.path import socket import ssl import eventlet import eventlet.wsgi import greenlet from oslo_log import log as logging from oslo_service import service from oslo_utils import excutils import nova.conf from nova import exception from nova.i18n import _, _LE, _LI from nova import utils CONF = nova.conf.CONF LOG = logging.getLogger(__name__) class Server(service.ServiceBase): """Server class to manage a WSGI server, serving a WSGI application.""" default_pool_size = CONF.wsgi.default_pool_size def __init__(self, name, app, host='0.0.0.0', port=0, pool_size=None, protocol=eventlet.wsgi.HttpProtocol, backlog=128, use_ssl=False, max_url_len=None): """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. :param backlog: Maximum number of queued connections. :param max_url_len: Maximum length of permitted URLs. :returns: None :raises: nova.exception.InvalidInput """ # Allow operators to customize http requests max header line size. eventlet.wsgi.MAX_HEADER_LINE = CONF.wsgi.max_header_line self.name = name self.app = app self._server = None self._protocol = protocol self.pool_size = pool_size or self.default_pool_size self._pool = eventlet.GreenPool(self.pool_size) self._logger = logging.getLogger("nova.%s.wsgi.server" % self.name) self._use_ssl = use_ssl self._max_url_len = max_url_len self.client_socket_timeout = CONF.wsgi.client_socket_timeout or None if backlog < 1: raise exception.InvalidInput( reason=_('The backlog must be more than 0')) 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 try: self._socket = eventlet.listen(bind_addr, family, backlog=backlog) except EnvironmentError: LOG.error(_LE("Could not bind to %(host)s:%(port)s"), {'host': host, 'port': port}) raise (self.host, self.port) = self._socket.getsockname()[0:2] LOG.info(_LI("%(name)s listening on %(host)s:%(port)s"), {'name': self.name, 'host': self.host, 'port': self.port}) def start(self): """Start serving a WSGI application. :returns: None """ # The server socket object will be closed after server exits, # but the underlying file descriptor will remain open, and will # give bad file descriptor error. So duplicating the socket object, # to keep file descriptor usable. dup_socket = self._socket.dup() dup_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) # sockets can hang around forever without keepalive dup_socket.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1) # This option isn't available in the OS X version of eventlet if hasattr(socket, 'TCP_KEEPIDLE'): dup_socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, CONF.wsgi.tcp_keepidle) if self._use_ssl: try: ca_file = CONF.wsgi.ssl_ca_file cert_file = CONF.wsgi.ssl_cert_file key_file = CONF.wsgi.ssl_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 self._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")) ssl_kwargs = { 'server_side': True, 'certfile': cert_file, 'keyfile': key_file, 'cert_reqs': ssl.CERT_NONE, } if CONF.wsgi.ssl_ca_file: ssl_kwargs['ca_certs'] = ca_file ssl_kwargs['cert_reqs'] = ssl.CERT_REQUIRED dup_socket = eventlet.wrap_ssl(dup_socket, **ssl_kwargs) except Exception: with excutils.save_and_reraise_exception(): LOG.error(_LE("Failed to start %(name)s on %(host)s" ":%(port)s with SSL support"), {'name': self.name, 'host': self.host, 'port': self.port}) wsgi_kwargs = { 'func': eventlet.wsgi.server, 'sock': dup_socket, 'site': self.app, 'protocol': self._protocol, 'custom_pool': self._pool, 'log': self._logger, 'log_format': CONF.wsgi.wsgi_log_format, 'debug': False, 'keepalive': CONF.wsgi.keep_alive, 'socket_timeout': self.client_socket_timeout } if self._max_url_len: wsgi_kwargs['url_length_limit'] = self._max_url_len self._server = utils.spawn(**wsgi_kwargs) def reset(self): """Reset server greenpool size to default. :returns: None """ self._pool.resize(self.pool_size) 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.")) if self._server is not None: # Resize pool to stop new requests from being processed self._pool.resize(0) 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: if self._server is not None: self._pool.waitall() self._server.wait() except greenlet.GreenletExit: LOG.info(_LI("WSGI server has stopped."))