797 lines
28 KiB
Python
797 lines
28 KiB
Python
# Copyright 2011 OpenStack Foundation.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""
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Utility methods for working with WSGI servers
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"""
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import errno
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import socket
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import sys
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import time
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import eventlet.wsgi
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from neutron_lib import context
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from neutron_lib import exceptions as exception
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from oslo_config import cfg
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import oslo_i18n
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from oslo_log import log as logging
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from oslo_serialization import jsonutils
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from oslo_service import service as common_service
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from oslo_service import sslutils
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from oslo_service import systemd
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from oslo_service import wsgi
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from oslo_utils import encodeutils
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from oslo_utils import excutils
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import six
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import webob.dec
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import webob.exc
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from neutron._i18n import _, _LE, _LI
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from neutron.common import config
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from neutron.common import exceptions as n_exc
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from neutron.conf import wsgi as wsgi_config
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from neutron.db import api
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from neutron import worker as neutron_worker
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CONF = cfg.CONF
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wsgi_config.register_socket_opts()
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LOG = logging.getLogger(__name__)
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def encode_body(body):
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"""Encode unicode body.
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WebOb requires to encode unicode body used to update response body.
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"""
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return encodeutils.to_utf8(body)
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class WorkerService(neutron_worker.NeutronWorker):
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"""Wraps a worker to be handled by ProcessLauncher"""
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def __init__(self, service, application, disable_ssl=False,
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worker_process_count=0):
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super(WorkerService, self).__init__(worker_process_count)
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self._service = service
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self._application = application
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self._disable_ssl = disable_ssl
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self._server = None
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def start(self):
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super(WorkerService, self).start()
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# When api worker is stopped it kills the eventlet wsgi server which
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# internally closes the wsgi server socket object. This server socket
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# object becomes not usable which leads to "Bad file descriptor"
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# errors on service restart.
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# Duplicate a socket object to keep a file descriptor usable.
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dup_sock = self._service._socket.dup()
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if CONF.use_ssl and not self._disable_ssl:
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dup_sock = sslutils.wrap(CONF, dup_sock)
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self._server = self._service.pool.spawn(self._service._run,
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self._application,
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dup_sock)
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def wait(self):
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if isinstance(self._server, eventlet.greenthread.GreenThread):
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self._server.wait()
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def stop(self):
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if isinstance(self._server, eventlet.greenthread.GreenThread):
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self._server.kill()
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self._server = None
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@staticmethod
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def reset():
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config.reset_service()
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class Server(object):
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"""Server class to manage multiple WSGI sockets and applications."""
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def __init__(self, name, num_threads=None, disable_ssl=False):
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# Raise the default from 8192 to accommodate large tokens
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eventlet.wsgi.MAX_HEADER_LINE = CONF.max_header_line
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self.num_threads = num_threads or CONF.wsgi_default_pool_size
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self.disable_ssl = disable_ssl
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# Pool for a greenthread in which wsgi server will be running
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self.pool = eventlet.GreenPool(1)
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self.name = name
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self._server = None
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# A value of 0 is converted to None because None is what causes the
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# wsgi server to wait forever.
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self.client_socket_timeout = CONF.client_socket_timeout or None
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if CONF.use_ssl and not self.disable_ssl:
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sslutils.is_enabled(CONF)
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def _get_socket(self, host, port, backlog):
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bind_addr = (host, port)
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# TODO(dims): eventlet's green dns/socket module does not actually
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# support IPv6 in getaddrinfo(). We need to get around this in the
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# future or monitor upstream for a fix
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try:
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info = socket.getaddrinfo(bind_addr[0],
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bind_addr[1],
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socket.AF_UNSPEC,
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socket.SOCK_STREAM)[0]
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family = info[0]
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bind_addr = info[-1]
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except Exception:
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LOG.exception(_LE("Unable to listen on %(host)s:%(port)s"),
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{'host': host, 'port': port})
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sys.exit(1)
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sock = None
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retry_until = time.time() + CONF.retry_until_window
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while not sock and time.time() < retry_until:
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try:
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sock = eventlet.listen(bind_addr,
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backlog=backlog,
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family=family)
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except socket.error as err:
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with excutils.save_and_reraise_exception() as ctxt:
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if err.errno == errno.EADDRINUSE:
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ctxt.reraise = False
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eventlet.sleep(0.1)
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if not sock:
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raise RuntimeError(_("Could not bind to %(host)s:%(port)s "
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"after trying for %(time)d seconds") %
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{'host': host,
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'port': port,
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'time': CONF.retry_until_window})
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sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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# sockets can hang around forever without keepalive
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sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
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# This option isn't available in the OS X version of eventlet
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if hasattr(socket, 'TCP_KEEPIDLE'):
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sock.setsockopt(socket.IPPROTO_TCP,
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socket.TCP_KEEPIDLE,
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CONF.tcp_keepidle)
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return sock
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def start(self, application, port, host='0.0.0.0', workers=0):
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"""Run a WSGI server with the given application."""
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self._host = host
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self._port = port
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backlog = CONF.backlog
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self._socket = self._get_socket(self._host,
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self._port,
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backlog=backlog)
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self._launch(application, workers)
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def _launch(self, application, workers=0):
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service = WorkerService(self, application, self.disable_ssl, workers)
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if workers < 1:
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# The API service should run in the current process.
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self._server = service
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# Dump the initial option values
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cfg.CONF.log_opt_values(LOG, logging.DEBUG)
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service.start()
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systemd.notify_once()
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else:
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# dispose the whole pool before os.fork, otherwise there will
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# be shared DB connections in child processes which may cause
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# DB errors.
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api.context_manager.dispose_pool()
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# The API service runs in a number of child processes.
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# Minimize the cost of checking for child exit by extending the
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# wait interval past the default of 0.01s.
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self._server = common_service.ProcessLauncher(cfg.CONF,
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wait_interval=1.0)
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self._server.launch_service(service,
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workers=service.worker_process_count)
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@property
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def host(self):
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return self._socket.getsockname()[0] if self._socket else self._host
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@property
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def port(self):
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return self._socket.getsockname()[1] if self._socket else self._port
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def stop(self):
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self._server.stop()
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def wait(self):
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"""Wait until all servers have completed running."""
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try:
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self._server.wait()
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except KeyboardInterrupt:
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pass
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def _run(self, application, socket):
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"""Start a WSGI server in a new green thread."""
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eventlet.wsgi.server(socket, application,
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max_size=self.num_threads,
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log=LOG,
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keepalive=CONF.wsgi_keep_alive,
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log_format=CONF.wsgi_log_format,
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socket_timeout=self.client_socket_timeout)
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class Request(wsgi.Request):
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def best_match_content_type(self):
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"""Determine the most acceptable content-type.
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Based on:
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1) URI extension (.json)
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2) Content-type header
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3) Accept* headers
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"""
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# First lookup http request path
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parts = self.path.rsplit('.', 1)
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if len(parts) > 1:
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_format = parts[1]
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if _format in ['json']:
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return 'application/{0}'.format(_format)
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#Then look up content header
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type_from_header = self.get_content_type()
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if type_from_header:
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return type_from_header
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ctypes = ['application/json']
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#Finally search in Accept-* headers
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bm = self.accept.best_match(ctypes)
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return bm or 'application/json'
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def get_content_type(self):
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allowed_types = ("application/json",)
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if "Content-Type" not in self.headers:
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LOG.debug("Missing Content-Type")
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return None
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_type = self.content_type
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if _type in allowed_types:
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return _type
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return None
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def best_match_language(self):
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"""Determines best available locale from the Accept-Language header.
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:returns: the best language match or None if the 'Accept-Language'
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header was not available in the request.
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"""
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if not self.accept_language:
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return None
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all_languages = oslo_i18n.get_available_languages('neutron')
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return self.accept_language.best_match(all_languages)
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@property
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def context(self):
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if 'neutron.context' not in self.environ:
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self.environ['neutron.context'] = context.get_admin_context()
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return self.environ['neutron.context']
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class ActionDispatcher(object):
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"""Maps method name to local methods through action name."""
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def dispatch(self, *args, **kwargs):
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"""Find and call local method."""
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action = kwargs.pop('action', 'default')
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action_method = getattr(self, str(action), self.default)
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return action_method(*args, **kwargs)
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def default(self, data):
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raise NotImplementedError()
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class DictSerializer(ActionDispatcher):
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"""Default request body serialization."""
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def serialize(self, data, action='default'):
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return self.dispatch(data, action=action)
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def default(self, data):
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return ""
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class JSONDictSerializer(DictSerializer):
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"""Default JSON request body serialization."""
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def default(self, data):
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def sanitizer(obj):
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return six.text_type(obj)
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return encode_body(jsonutils.dumps(data, default=sanitizer))
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class ResponseHeaderSerializer(ActionDispatcher):
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"""Default response headers serialization."""
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def serialize(self, response, data, action):
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self.dispatch(response, data, action=action)
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def default(self, response, data):
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response.status_int = 200
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class ResponseSerializer(object):
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"""Encode the necessary pieces into a response object."""
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def __init__(self, body_serializers=None, headers_serializer=None):
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self.body_serializers = {
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'application/json': JSONDictSerializer(),
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}
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self.body_serializers.update(body_serializers or {})
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self.headers_serializer = (headers_serializer or
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ResponseHeaderSerializer())
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def serialize(self, response_data, content_type, action='default'):
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"""Serialize a dict into a string and wrap in a wsgi.Request object.
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:param response_data: dict produced by the Controller
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:param content_type: expected mimetype of serialized response body
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"""
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response = webob.Response()
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self.serialize_headers(response, response_data, action)
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self.serialize_body(response, response_data, content_type, action)
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return response
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def serialize_headers(self, response, data, action):
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self.headers_serializer.serialize(response, data, action)
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def serialize_body(self, response, data, content_type, action):
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response.headers['Content-Type'] = content_type
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if data is not None:
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serializer = self.get_body_serializer(content_type)
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response.body = serializer.serialize(data, action)
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def get_body_serializer(self, content_type):
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try:
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return self.body_serializers[content_type]
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except (KeyError, TypeError):
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raise exception.InvalidContentType(content_type=content_type)
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class TextDeserializer(ActionDispatcher):
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"""Default request body deserialization."""
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def deserialize(self, datastring, action='default'):
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return self.dispatch(datastring, action=action)
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def default(self, datastring):
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return {}
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class JSONDeserializer(TextDeserializer):
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def _from_json(self, datastring):
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try:
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return jsonutils.loads(datastring)
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except ValueError:
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msg = _("Cannot understand JSON")
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raise n_exc.MalformedRequestBody(reason=msg)
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def default(self, datastring):
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return {'body': self._from_json(datastring)}
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class RequestHeadersDeserializer(ActionDispatcher):
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"""Default request headers deserializer."""
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def deserialize(self, request, action):
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return self.dispatch(request, action=action)
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def default(self, request):
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return {}
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class RequestDeserializer(object):
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"""Break up a Request object into more useful pieces."""
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def __init__(self, body_deserializers=None, headers_deserializer=None):
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self.body_deserializers = {
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'application/json': JSONDeserializer(),
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}
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self.body_deserializers.update(body_deserializers or {})
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self.headers_deserializer = (headers_deserializer or
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RequestHeadersDeserializer())
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def deserialize(self, request):
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"""Extract necessary pieces of the request.
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:param request: Request object
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:returns: tuple of expected controller action name, dictionary of
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keyword arguments to pass to the controller, the expected
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content type of the response
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"""
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action_args = self.get_action_args(request.environ)
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action = action_args.pop('action', None)
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action_args.update(self.deserialize_headers(request, action))
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action_args.update(self.deserialize_body(request, action))
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accept = self.get_expected_content_type(request)
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return (action, action_args, accept)
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def deserialize_headers(self, request, action):
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return self.headers_deserializer.deserialize(request, action)
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def deserialize_body(self, request, action):
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try:
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content_type = request.best_match_content_type()
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except exception.InvalidContentType:
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LOG.debug("Unrecognized Content-Type provided in request")
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return {}
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if content_type is None:
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LOG.debug("No Content-Type provided in request")
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return {}
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if not len(request.body) > 0:
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LOG.debug("Empty body provided in request")
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return {}
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try:
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deserializer = self.get_body_deserializer(content_type)
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except exception.InvalidContentType:
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with excutils.save_and_reraise_exception():
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LOG.debug("Unable to deserialize body as provided "
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"Content-Type")
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return deserializer.deserialize(request.body, action)
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def get_body_deserializer(self, content_type):
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try:
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return self.body_deserializers[content_type]
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except (KeyError, TypeError):
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raise exception.InvalidContentType(content_type=content_type)
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def get_expected_content_type(self, request):
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return request.best_match_content_type()
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def get_action_args(self, request_environment):
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"""Parse dictionary created by routes library."""
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try:
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args = request_environment['wsgiorg.routing_args'][1].copy()
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except Exception:
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return {}
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try:
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del args['controller']
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except KeyError:
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pass
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try:
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del args['format']
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except KeyError:
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pass
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return args
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class Application(object):
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"""Base WSGI application wrapper. Subclasses need to implement __call__."""
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@classmethod
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def factory(cls, global_config, **local_config):
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"""Used for paste app factories in paste.deploy config files.
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Any local configuration (that is, values under the [app:APPNAME]
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section of the paste config) will be passed into the `__init__` method
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as kwargs.
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A hypothetical configuration would look like:
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[app:wadl]
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latest_version = 1.3
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paste.app_factory = nova.api.fancy_api:Wadl.factory
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which would result in a call to the `Wadl` class as
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import neutron.api.fancy_api
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fancy_api.Wadl(latest_version='1.3')
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You could of course re-implement the `factory` method in subclasses,
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but using the kwarg passing it shouldn't be necessary.
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"""
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return cls(**local_config)
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def __call__(self, environ, start_response):
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r"""Subclasses will probably want to implement __call__ like this:
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@webob.dec.wsgify(RequestClass=Request)
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def __call__(self, req):
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# Any of the following objects work as responses:
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# Option 1: simple string
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res = 'message\n'
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# Option 2: a nicely formatted HTTP exception page
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res = exc.HTTPForbidden(explanation='Nice try')
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# Option 3: a webob Response object (in case you need to play with
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# headers, or you want to be treated like an iterable, or or or)
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res = Response();
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res.app_iter = open('somefile')
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# Option 4: any wsgi app to be run next
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res = self.application
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# Option 5: you can get a Response object for a wsgi app, too, to
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# play with headers etc
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res = req.get_response(self.application)
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# You can then just return your response...
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return res
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# ... or set req.response and return None.
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req.response = res
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See the end of http://pythonpaste.org/webob/modules/dec.html
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for more info.
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"""
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raise NotImplementedError(_('You must implement __call__'))
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class Resource(Application):
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"""WSGI app that handles (de)serialization and controller dispatch.
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|
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WSGI app that reads routing information supplied by RoutesMiddleware
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and calls the requested action method upon its controller. All
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|
controller action methods must accept a 'req' argument, which is the
|
|
incoming wsgi.Request. If the operation is a PUT or POST, the controller
|
|
method must also accept a 'body' argument (the deserialized request body).
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|
They may raise a webob.exc exception or return a dict, which will be
|
|
serialized by requested content type.
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|
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"""
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|
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def __init__(self, controller, fault_body_function,
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deserializer=None, serializer=None):
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"""Object initialization.
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|
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|
:param controller: object that implement methods created by routes lib
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:param deserializer: object that can serialize the output of a
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|
controller into a webob response
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:param serializer: object that can deserialize a webob request
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|
into necessary pieces
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|
:param fault_body_function: a function that will build the response
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|
body for HTTP errors raised by operations
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|
on this resource object
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|
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"""
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self.controller = controller
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self.deserializer = deserializer or RequestDeserializer()
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self.serializer = serializer or ResponseSerializer()
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self._fault_body_function = fault_body_function
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@webob.dec.wsgify(RequestClass=Request)
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def __call__(self, request):
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"""WSGI method that controls (de)serialization and method dispatch."""
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|
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LOG.info(_LI("%(method)s %(url)s"),
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{"method": request.method, "url": request.url})
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|
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try:
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action, args, accept = self.deserializer.deserialize(request)
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except exception.InvalidContentType:
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msg = _("Unsupported Content-Type")
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LOG.exception(_LE("InvalidContentType: %s"), msg)
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|
return Fault(webob.exc.HTTPBadRequest(explanation=msg))
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|
except n_exc.MalformedRequestBody:
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|
msg = _("Malformed request body")
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|
LOG.exception(_LE("MalformedRequestBody: %s"), msg)
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return Fault(webob.exc.HTTPBadRequest(explanation=msg))
|
|
|
|
try:
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|
action_result = self.dispatch(request, action, args)
|
|
except webob.exc.HTTPException as ex:
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|
LOG.info(_LI("HTTP exception thrown: %s"), ex)
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|
action_result = Fault(ex, self._fault_body_function)
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|
except Exception:
|
|
LOG.exception(_LE("Internal error"))
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# Do not include the traceback to avoid returning it to clients.
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|
action_result = Fault(webob.exc.HTTPServerError(),
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|
self._fault_body_function)
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|
|
|
if isinstance(action_result, dict) or action_result is None:
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|
response = self.serializer.serialize(action_result,
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accept,
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action=action)
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else:
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|
response = action_result
|
|
|
|
try:
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|
LOG.info(_LI("%(url)s returned with HTTP %(status)d"),
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dict(url=request.url, status=response.status_int))
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|
except AttributeError as e:
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|
LOG.info(_LI("%(url)s returned a fault: %(exception)s"),
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|
dict(url=request.url, exception=e))
|
|
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return response
|
|
|
|
def dispatch(self, request, action, action_args):
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|
"""Find action-specific method on controller and call it."""
|
|
|
|
controller_method = getattr(self.controller, action)
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|
try:
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|
#NOTE(salvatore-orlando): the controller method must have
|
|
# an argument whose name is 'request'
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|
return controller_method(request=request, **action_args)
|
|
except TypeError:
|
|
LOG.exception(_LE('Invalid request'))
|
|
return Fault(webob.exc.HTTPBadRequest())
|
|
|
|
|
|
def _default_body_function(wrapped_exc):
|
|
code = wrapped_exc.status_int
|
|
fault_data = {
|
|
'Error': {
|
|
'code': code,
|
|
'message': wrapped_exc.explanation}}
|
|
# 'code' is an attribute on the fault tag itself
|
|
metadata = {'attributes': {'Error': 'code'}}
|
|
return fault_data, metadata
|
|
|
|
|
|
class Fault(webob.exc.HTTPException):
|
|
"""Generates an HTTP response from a webob HTTP exception."""
|
|
|
|
def __init__(self, exception, body_function=None):
|
|
"""Creates a Fault for the given webob.exc.exception."""
|
|
self.wrapped_exc = exception
|
|
self.status_int = self.wrapped_exc.status_int
|
|
self._body_function = body_function or _default_body_function
|
|
|
|
@webob.dec.wsgify(RequestClass=Request)
|
|
def __call__(self, req):
|
|
"""Generate a WSGI response based on the exception passed to ctor."""
|
|
# Replace the body with fault details.
|
|
fault_data, metadata = self._body_function(self.wrapped_exc)
|
|
content_type = req.best_match_content_type()
|
|
serializer = {
|
|
'application/json': JSONDictSerializer(),
|
|
}[content_type]
|
|
|
|
self.wrapped_exc.body = serializer.serialize(fault_data)
|
|
self.wrapped_exc.content_type = content_type
|
|
return self.wrapped_exc
|
|
|
|
|
|
# NOTE(salvatore-orlando): this class will go once the
|
|
# extension API framework is updated
|
|
class Controller(object):
|
|
"""WSGI app that dispatched to methods.
|
|
|
|
WSGI app that reads routing information supplied by RoutesMiddleware
|
|
and calls the requested action method upon itself. All action methods
|
|
must, in addition to their normal parameters, accept a 'req' argument
|
|
which is the incoming wsgi.Request. They raise a webob.exc exception,
|
|
or return a dict which will be serialized by requested content type.
|
|
|
|
"""
|
|
|
|
@webob.dec.wsgify(RequestClass=Request)
|
|
def __call__(self, req):
|
|
"""Call the method specified in req.environ by RoutesMiddleware."""
|
|
arg_dict = req.environ['wsgiorg.routing_args'][1]
|
|
action = arg_dict['action']
|
|
method = getattr(self, action)
|
|
del arg_dict['controller']
|
|
del arg_dict['action']
|
|
if 'format' in arg_dict:
|
|
del arg_dict['format']
|
|
arg_dict['request'] = req
|
|
result = method(**arg_dict)
|
|
|
|
if isinstance(result, dict) or result is None:
|
|
if result is None:
|
|
status = 204
|
|
content_type = ''
|
|
body = None
|
|
else:
|
|
status = 200
|
|
content_type = req.best_match_content_type()
|
|
body = self._serialize(result, content_type)
|
|
|
|
response = webob.Response(status=status,
|
|
content_type=content_type,
|
|
body=body)
|
|
LOG.debug("%(url)s returned with HTTP %(status)d",
|
|
dict(url=req.url, status=response.status_int))
|
|
return response
|
|
else:
|
|
return result
|
|
|
|
def _serialize(self, data, content_type):
|
|
"""Serialize the given dict to the provided content_type.
|
|
|
|
Uses self._serialization_metadata if it exists, which is a dict mapping
|
|
MIME types to information needed to serialize to that type.
|
|
|
|
"""
|
|
_metadata = getattr(type(self), '_serialization_metadata', {})
|
|
|
|
serializer = Serializer(_metadata)
|
|
try:
|
|
return serializer.serialize(data, content_type)
|
|
except exception.InvalidContentType:
|
|
msg = _('The requested content type %s is invalid.') % content_type
|
|
raise webob.exc.HTTPNotAcceptable(msg)
|
|
|
|
def _deserialize(self, data, content_type):
|
|
"""Deserialize the request body to the specified content type.
|
|
|
|
Uses self._serialization_metadata if it exists, which is a dict mapping
|
|
MIME types to information needed to serialize to that type.
|
|
|
|
"""
|
|
_metadata = getattr(type(self), '_serialization_metadata', {})
|
|
serializer = Serializer(_metadata)
|
|
return serializer.deserialize(data, content_type)['body']
|
|
|
|
|
|
# NOTE(salvatore-orlando): this class will go once the
|
|
# extension API framework is updated
|
|
class Serializer(object):
|
|
"""Serializes and deserializes dictionaries to certain MIME types."""
|
|
|
|
def __init__(self, metadata=None):
|
|
"""Create a serializer based on the given WSGI environment.
|
|
|
|
'metadata' is an optional dict mapping MIME types to information
|
|
needed to serialize a dictionary to that type.
|
|
|
|
"""
|
|
self.metadata = metadata or {}
|
|
|
|
def _get_serialize_handler(self, content_type):
|
|
handlers = {
|
|
'application/json': JSONDictSerializer(),
|
|
}
|
|
|
|
try:
|
|
return handlers[content_type]
|
|
except Exception:
|
|
raise exception.InvalidContentType(content_type=content_type)
|
|
|
|
def serialize(self, data, content_type):
|
|
"""Serialize a dictionary into the specified content type."""
|
|
return self._get_serialize_handler(content_type).serialize(data)
|
|
|
|
def deserialize(self, datastring, content_type):
|
|
"""Deserialize a string to a dictionary.
|
|
|
|
The string must be in the format of a supported MIME type.
|
|
|
|
"""
|
|
try:
|
|
return self.get_deserialize_handler(content_type).deserialize(
|
|
datastring)
|
|
except Exception:
|
|
raise webob.exc.HTTPBadRequest(_("Could not deserialize data"))
|
|
|
|
def get_deserialize_handler(self, content_type):
|
|
handlers = {
|
|
'application/json': JSONDeserializer(),
|
|
}
|
|
|
|
try:
|
|
return handlers[content_type]
|
|
except Exception:
|
|
raise exception.InvalidContentType(content_type=content_type)
|