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manila/manila/wsgi.py

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# 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_log import loggers
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")
self._wsgi_logger = loggers.WritableLogger(self._logger)
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._wsgi_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)
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