gns3-server/gns3server/web/web_server.py
Julien Duponchelle 342bcdb5b6
CORS support
Fix #530
2016-05-17 12:39:23 +02:00

247 lines
8.1 KiB
Python

# -*- coding: utf-8 -*-
#
# Copyright (C) 2015 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
Set up and run the server.
"""
import os
import sys
import signal
import asyncio
import aiohttp
import aiohttp_cors
import functools
import types
import time
import atexit
from .route import Route
from .request_handler import RequestHandler
from ..config import Config
from ..compute import MODULES
from ..compute.port_manager import PortManager
from ..controller import Controller
# do not delete this import
import gns3server.handlers
import logging
log = logging.getLogger(__name__)
class WebServer:
def __init__(self, host, port):
self._host = host
self._port = port
self._loop = None
self._handler = None
self._start_time = time.time()
self._port_manager = PortManager(host)
@staticmethod
def instance(host=None, port=None):
"""
Singleton to return only one instance of Server.
:returns: instance of Server
"""
if not hasattr(WebServer, "_instance") or WebServer._instance is None:
assert host is not None
assert port is not None
WebServer._instance = WebServer(host, port)
return WebServer._instance
@asyncio.coroutine
def _run_application(self, handler, ssl_context=None):
try:
server = yield from self._loop.create_server(handler, self._host, self._port, ssl=ssl_context)
except OSError as e:
log.critical("Could not start the server: {}".format(e))
self._loop.stop()
return
return server
@asyncio.coroutine
def shutdown_server(self):
"""
Cleanly shutdown the server.
"""
if self._handler:
yield from self._handler.finish_connections()
self._handler = None
for module in MODULES:
log.debug("Unloading module {}".format(module.__name__))
m = module.instance()
yield from m.unload()
if self._port_manager.tcp_ports:
log.warning("TCP ports are still used {}".format(self._port_manager.tcp_ports))
if self._port_manager.udp_ports:
log.warning("UDP ports are still used {}".format(self._port_manager.udp_ports))
for task in asyncio.Task.all_tasks():
task.cancel()
self._loop.stop()
def _signal_handling(self):
def signal_handler(signame):
log.warning("Server has got signal {}, exiting...".format(signame))
asyncio.async(self.shutdown_server())
signals = ["SIGTERM", "SIGINT"]
if sys.platform.startswith("win"):
signals.extend(["SIGBREAK"])
else:
signals.extend(["SIGHUP", "SIGQUIT"])
for signal_name in signals:
callback = functools.partial(signal_handler, signal_name)
if sys.platform.startswith("win"):
# add_signal_handler() is not yet supported on Windows
signal.signal(getattr(signal, signal_name), callback)
else:
self._loop.add_signal_handler(getattr(signal, signal_name), callback)
def _create_ssl_context(self, server_config):
import ssl
ssl_context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
certfile = server_config["certfile"]
certkey = server_config["certkey"]
try:
ssl_context.load_cert_chain(certfile, certkey)
except FileNotFoundError:
log.critical("Could not find the SSL certfile or certkey")
raise SystemExit
except ssl.SSLError as e:
log.critical("SSL error: {}".format(e))
raise SystemExit
log.info("SSL is enabled")
return ssl_context
@asyncio.coroutine
def start_shell(self):
try:
from ptpython.repl import embed
except ImportError:
log.error("Unable to start a shell: the ptpython module must be installed!")
return
yield from embed(globals(), locals(), return_asyncio_coroutine=True, patch_stdout=True)
def _exit_handling(self):
"""
Makes sure the asyncio loop is closed.
"""
def close_asyncio_loop():
loop = None
try:
loop = asyncio.get_event_loop()
except AttributeError:
pass
if loop is not None:
loop.close()
atexit.register(close_asyncio_loop)
def run(self):
"""
Starts the server.
"""
logger = logging.getLogger("asyncio")
logger.setLevel(logging.ERROR)
server_config = Config.instance().get_section_config("Server")
if sys.platform.startswith("win"):
# use the Proactor event loop on Windows
loop = asyncio.ProactorEventLoop()
# Add a periodic callback to give a chance to process signals on Windows
# because asyncio.add_signal_handler() is not supported yet on that platform
# otherwise the loop runs outside of signal module's ability to trap signals.
def wakeup():
loop.call_later(0.5, wakeup)
loop.call_later(0.5, wakeup)
asyncio.set_event_loop(loop)
ssl_context = None
if server_config.getboolean("ssl"):
if sys.platform.startswith("win"):
log.critical("SSL mode is not supported on Windows")
raise SystemExit
ssl_context = self._create_ssl_context(server_config)
self._loop = asyncio.get_event_loop()
# Asyncio will raise error if coroutine is not called
self._loop.set_debug(True)
if server_config.getboolean("controller"):
asyncio.async(Controller.instance().load())
for key, val in os.environ.items():
log.debug("ENV %s=%s", key, val)
app = aiohttp.web.Application()
# Allow CORS for this domains
cors = aiohttp_cors.setup(app, defaults={
# Default web server for web gui dev
"http://localhost:8080": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*")
})
for method, route, handler in Route.get_routes():
log.debug("Adding route: {} {}".format(method, route))
cors.add(app.router.add_route(method, route, handler))
for module in MODULES:
log.debug("Loading module {}".format(module.__name__))
m = module.instance()
m.port_manager = self._port_manager
log.info("Starting server on {}:{}".format(self._host, self._port))
self._handler = app.make_handler(handler=RequestHandler)
server = self._run_application(self._handler, ssl_context)
self._loop.run_until_complete(server)
self._signal_handling()
self._exit_handling()
if server_config.getboolean("shell"):
asyncio.async(self.start_shell())
try:
self._loop.run_forever()
except TypeError as e:
# This is to ignore an asyncio.windows_events exception
# on Windows when the process gets the SIGBREAK signal
# TypeError: async() takes 1 positional argument but 3 were given
log.warning("TypeError exception in the loop {}".format(e))
finally:
if self._handler and self._loop.is_running():
self._loop.run_until_complete(self._handler.finish_connections())
server.close()
if self._loop.is_running():
self._loop.run_until_complete(app.finish())