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gns3-server/gns3server/web/web_server.py
Julien Duponchelle 3dc478385b
When connecting to a compute node ask for qemu images list
The server start to compute qemu image list in background
because first time discovery could be slow due to the compute
time of md5sum.

Fix #996
2017-05-15 15:35:48 +02:00

285 lines
9.5 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
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__)
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
@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 (OSError, asyncio.CancelledError) as e:
log.critical("Could not start the server: {}".format(e))
return False
return True
@asyncio.coroutine
def shutdown_server(self):
"""
Cleanly shutdown the server.
"""
if not self._closing:
self._closing = True
else:
log.warning("Close is already in progress")
return
if self._server:
self._server.close()
yield from self._server.wait_closed()
if self._app:
yield from self._app.shutdown()
if self._handler:
yield from self._handler.finish_connections(2) # Parameter is timeout
if self._app:
yield from self._app.cleanup()
yield from Controller.instance().stop()
for module in MODULES:
log.debug("Unloading module {}".format(module.__name__))
m = module.instance()
yield from 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:
yield from asyncio.wait_for(task, 1)
except:
pass
self._loop.stop()
def _signal_handling(self):
def signal_handler(signame, *args):
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, 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)
@asyncio.coroutine
def _on_startup(self, *args):
"""
Called when the HTTP server start
"""
yield from Controller.instance().start()
# Because with a large image collection
# without md5sum already computed we start the
# computing with server start
asyncio.async(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")
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)
for key, val in os.environ.items():
log.debug("ENV %s=%s", key, val)
self._app = aiohttp.web.Application()
# Background task started with the server
self._app.on_startup.append(self._on_startup)
# 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": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
"http://localhost:8080": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*"),
"http://gns3.github.io": aiohttp_cors.ResourceOptions(expose_headers="*", allow_headers="*")
})
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, ssl_context) is False:
self._loop.stop()
return
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._loop.is_running():
self._loop.run_until_complete(self.shutdown_server())