gns3-server/gns3server/server.py

231 lines
7.8 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 functools
import types
import time
from .web.route import Route
from .web.request_handler import RequestHandler
from .config import Config
from .modules import MODULES
from .modules.port_manager import PortManager
# do not delete this import
import gns3server.handlers
import logging
log = logging.getLogger(__name__)
class Server:
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(Server, "_instance") or Server._instance is None:
Server._instance = Server(host, port)
return Server._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()
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))
self._loop.stop()
def _signal_handling(self):
@asyncio.coroutine
def signal_handler(signame):
log.warning("Server has got signal {}, exiting...".format(signame))
yield from 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(asyncio.async, 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 _reload_hook(self):
@asyncio.coroutine
def reload():
log.info("Reloading")
yield from self.shutdown_server()
os.execv(sys.executable, [sys.executable] + sys.argv)
# code extracted from tornado
for module in sys.modules.values():
# Some modules play games with sys.modules (e.g. email/__init__.py
# in the standard library), and occasionally this can cause strange
# failures in getattr. Just ignore anything that's not an ordinary
# module.
if not isinstance(module, types.ModuleType):
continue
path = getattr(module, "__file__", None)
if not path:
continue
if path.endswith(".pyc") or path.endswith(".pyo"):
path = path[:-1]
modified = os.stat(path).st_mtime
if modified > self._start_time:
log.debug("File {} has been modified".format(path))
asyncio.async(reload())
self._loop.call_later(1, self._reload_hook)
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
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 run(self):
"""
Starts the server.
"""
logger = logging.getLogger("asyncio")
logger.setLevel(logging.WARNING)
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(0.1, wakeup)
loop.call_later(0.1, 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()
app = aiohttp.web.Application()
for method, route, handler in Route.get_routes():
log.debug("Adding route: {} {}".format(method, route))
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)
self._loop.run_until_complete(self._run_application(self._handler, ssl_context))
self._signal_handling()
if server_config.getboolean("live"):
log.info("Code live reload is enabled, watching for file changes")
self._loop.call_later(1, self._reload_hook)
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 get the SIGBREAK signal
# TypeError: async() takes 1 positional argument but 3 were given
log.warning("TypeError exception in the loop {}".format(e))