gns3-server/gns3server/web/web_server.py

340 lines
11 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 time
import atexit
import weakref
# Import encoding now, to avoid implicit import later.
# Implicit import within threads may cause LookupError when standard library is in a ZIP
import encodings.idna
from .route import Route
from ..config import Config
from ..compute import MODULES
from ..compute.port_manager import PortManager
from ..compute.qemu import Qemu
from ..controller import Controller
# do not delete this import
import gns3server.handlers
import logging
log = logging.getLogger(__name__)
if not (aiohttp.__version__.startswith("3.")):
raise RuntimeError("aiohttp 3.x is required to run the GNS3 server")
class WebServer:
def __init__(self, host, port):
self._host = host
self._port = port
self._loop = None
self._handler = None
self._server = None
self._app = None
self._start_time = time.time()
self._running = False
self._closing = False
self._ssl_context = None
@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
def _run_application(self, handler, ssl_context=None):
try:
srv = self._loop.create_server(handler, self._host, self._port, ssl=ssl_context)
self._server, startup_res = self._loop.run_until_complete(asyncio.gather(srv, self._app.startup(), loop=self._loop))
except (RuntimeError, OSError, asyncio.CancelledError) as e:
log.critical("Could not start the server: {}".format(e))
return False
return True
async def reload_server(self):
"""
Reload the server.
"""
await Controller.instance().reload()
async def shutdown_server(self):
"""
Cleanly shutdown the server.
"""
if not self._closing:
self._closing = True
else:
log.warning("Close is already in progress")
return
# close websocket connections
websocket_connections = set(self._app['websockets'])
if websocket_connections:
log.info("Closing {} websocket connections...".format(len(websocket_connections)))
for ws in websocket_connections:
await ws.close(code=aiohttp.WSCloseCode.GOING_AWAY, message='Server shutdown')
if self._server:
self._server.close()
await self._server.wait_closed()
if self._app:
await self._app.shutdown()
if self._handler:
await self._handler.shutdown(2) # Parameter is timeout
if self._app:
await self._app.cleanup()
await Controller.instance().stop()
for module in MODULES:
log.debug("Unloading module {}".format(module.__name__))
m = module.instance()
await m.unload()
if PortManager.instance().tcp_ports:
log.warning("TCP ports are still used {}".format(PortManager.instance().tcp_ports))
if PortManager.instance().udp_ports:
log.warning("UDP ports are still used {}".format(PortManager.instance().udp_ports))
for task in asyncio.Task.all_tasks():
task.cancel()
try:
await asyncio.wait_for(task, 1)
except BaseException:
pass
self._loop.stop()
def ssl_context(self):
"""
Returns the SSL context for the server.
"""
return self._ssl_context
def _signal_handling(self):
def signal_handler(signame, *args):
try:
if signame == "SIGHUP":
log.info("Server has got signal {}, reloading...".format(signame))
asyncio.ensure_future(self.reload_server())
else:
log.warning("Server has got signal {}, exiting...".format(signame))
asyncio.ensure_future(self.shutdown_server())
except asyncio.CancelledError:
pass
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
async def start_shell(self):
log.error("The embedded shell has been deactivated in this version of GNS3")
return
try:
from ptpython.repl import embed
except ImportError:
log.error("Unable to start a shell: the ptpython module must be installed!")
return
await embed(globals(), locals(), return_asyncio_coroutine=True, patch_stdout=True, history_filename=".gns3_shell_history")
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)
async def _on_startup(self, *args):
"""
Called when the HTTP server start
"""
await Controller.instance().start()
# Because with a large image collection
# without md5sum already computed we start the
# computing with server start
asyncio.ensure_future(Qemu.instance().list_images())
def run(self):
"""
Starts the server.
"""
server_logger = logging.getLogger('aiohttp.server')
# In debug mode we don't use the standard request log but a more complete in response.py
if log.getEffectiveLevel() == logging.DEBUG:
server_logger.setLevel(logging.CRITICAL)
logger = logging.getLogger("asyncio")
logger.setLevel(logging.ERROR)
if sys.platform.startswith("win"):
loop = asyncio.get_event_loop()
# 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)
server_config = Config.instance().get_section_config("Server")
self._ssl_context = None
if server_config.getboolean("ssl"):
if sys.platform.startswith("win"):
log.critical("SSL mode is not supported on Windows")
raise SystemExit
self._ssl_context = self._create_ssl_context(server_config)
self._loop = asyncio.get_event_loop()
if log.getEffectiveLevel() == logging.DEBUG:
# On debug version we enable info that
# coroutine is not called in a way await/await
self._loop.set_debug(True)
for key, val in os.environ.items():
log.debug("ENV %s=%s", key, val)
self._app = aiohttp.web.Application()
# Keep a list of active websocket connections
self._app['websockets'] = weakref.WeakSet()
# Background task started with the server
self._app.on_startup.append(self._on_startup)
resource_options = aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*", max_age=0)
# Allow CORS for this domains
cors = aiohttp_cors.setup(self._app, defaults={
# Default web server for web gui dev
"http://127.0.0.1:8080": resource_options,
"http://localhost:8080": resource_options,
"http://127.0.0.1:4200": resource_options,
"http://localhost:4200": resource_options,
"http://gns3.github.io": resource_options,
"https://gns3.github.io": resource_options
})
PortManager.instance().console_host = self._host
for method, route, handler in Route.get_routes():
log.debug("Adding route: {} {}".format(method, route))
cors.add(self._app.router.add_route(method, route, handler))
for module in MODULES:
log.debug("Loading module {}".format(module.__name__))
m = module.instance()
m.port_manager = PortManager.instance()
log.info("Starting server on {}:{}".format(self._host, self._port))
self._handler = self._app.make_handler()
if self._run_application(self._handler, self._ssl_context) is False:
self._loop.stop()
sys.exit(1)
self._signal_handling()
self._exit_handling()
if server_config.getboolean("shell"):
asyncio.ensure_future(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._loop.is_running():
try:
self._loop.run_until_complete(self.shutdown_server())
except asyncio.CancelledError:
pass