gns3-server/gns3server/ubridge/hypervisor.py
2015-12-18 18:20:56 +01:00

231 lines
7.7 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/>.
"""
Represents a uBridge hypervisor and starts/stops the associated uBridge process.
"""
import os
import subprocess
import asyncio
import socket
import re
from pkg_resources import parse_version
from gns3server.utils.asyncio import wait_for_process_termination
from gns3server.utils.asyncio import subprocess_check_output
from .ubridge_hypervisor import UBridgeHypervisor
from .ubridge_error import UbridgeError
import logging
log = logging.getLogger(__name__)
class Hypervisor(UBridgeHypervisor):
"""
Hypervisor.
:param project: Project instance
:param path: path to uBridge executable
:param working_dir: working directory
:param host: host/address for this hypervisor
:param port: port for this hypervisor
"""
_instance_count = 1
def __init__(self, project, path, working_dir, host, port=None):
if port is None:
try:
port = None
info = socket.getaddrinfo(host, 0, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE)
if not info:
raise UbridgeError("getaddrinfo returns an empty list on {}".format(host))
for res in info:
af, socktype, proto, _, sa = res
# let the OS find an unused port for the uBridge hypervisor
with socket.socket(af, socktype, proto) as sock:
sock.bind(sa)
port = sock.getsockname()[1]
break
except OSError as e:
raise UbridgeError("Could not find free port for the uBridge hypervisor: {}".format(e))
super().__init__(host, port)
self._project = project
self._path = path
self._working_dir = working_dir
self._command = []
self._process = None
self._stdout_file = ""
self._started = False
@property
def process(self):
"""
Returns the subprocess of the Hypervisor
:returns: subprocess
"""
return self._process
@property
def started(self):
"""
Returns either this hypervisor has been started or not.
:returns: boolean
"""
return self._started
@property
def path(self):
"""
Returns the path to the uBridge executable.
:returns: path to uBridge
"""
return self._path
@path.setter
def path(self, path):
"""
Sets the path to the uBridge executable.
:param path: path to uBridge
"""
self._path = path
@asyncio.coroutine
def _check_ubridge_version(self):
"""
Checks if the ubridge executable version is >= 0.9.1
"""
try:
output = yield from subprocess_check_output(self._path, "-v", cwd=self._working_dir)
match = re.search("ubridge version ([0-9a-z\.]+)", output)
if match:
version = match.group(1)
if parse_version(version) < parse_version("0.9.1"):
raise UbridgeError("uBridge executable version must be >= 0.9.1")
else:
raise UbridgeError("Could not determine uBridge version for {}".format(self._path))
except (OSError, subprocess.SubprocessError) as e:
raise UbridgeError("Error while looking for uBridge version: {}".format(e))
@asyncio.coroutine
def start(self):
"""
Starts the uBridge hypervisor process.
"""
yield from self._check_ubridge_version()
try:
command = self._build_command()
log.info("starting ubridge: {}".format(command))
self._stdout_file = os.path.join(self._working_dir, "ubridge.log")
log.info("logging to {}".format(self._stdout_file))
with open(self._stdout_file, "w", encoding="utf-8") as fd:
self._process = yield from asyncio.create_subprocess_exec(*command,
stdout=fd,
stderr=subprocess.STDOUT,
cwd=self._working_dir)
log.info("ubridge started PID={}".format(self._process.pid))
except (OSError, subprocess.SubprocessError) as e:
ubridge_stdout = self.read_stdout()
log.error("Could not start ubridge: {}\n{}".format(e, ubridge_stdout))
raise UBridgeHypervisor("Could not start ubridge: {}\n{}".format(e, ubridge_stdout))
def _termination_callback(self, returncode):
"""
Called when the process has stopped.
:param returncode: Process returncode
"""
log.info("uBridge process has stopped, return code: %d", returncode)
if returncode != 0:
self._project.emit("log.error", {"message": "uBridge process has stopped, return code: {}\n{}".format(returncode, self.read_stdout())})
@asyncio.coroutine
def stop(self):
"""
Stops the uBridge hypervisor process.
"""
if self.is_running():
log.info("Stopping uBridge process PID={}".format(self._process.pid))
yield from UBridgeHypervisor.stop(self)
try:
yield from wait_for_process_termination(self._process, timeout=3)
except asyncio.TimeoutError:
if self._process.returncode is None:
log.warn("uBridge process {} is still running... killing it".format(self._process.pid))
self._process.kill()
if self._stdout_file and os.access(self._stdout_file, os.W_OK):
try:
os.remove(self._stdout_file)
except OSError as e:
log.warning("could not delete temporary uBridge log file: {}".format(e))
self._started = False
def read_stdout(self):
"""
Reads the standard output of the uBridge process.
Only use when the process has been stopped or has crashed.
"""
output = ""
if self._stdout_file and os.access(self._stdout_file, os.R_OK):
try:
with open(self._stdout_file, "rb") as file:
output = file.read().decode("utf-8", errors="replace")
except OSError as e:
log.warn("could not read {}: {}".format(self._stdout_file, e))
return output
def is_running(self):
"""
Checks if the process is running
:returns: True or False
"""
if self._process and self._process.returncode is None:
return True
return False
def _build_command(self):
"""
Command to start the uBridge hypervisor process.
(to be passed to subprocess.Popen())
"""
command = [self._path]
command.extend(["-H", "{}:{}".format(self._host, self._port)])
if log.getEffectiveLevel() == logging.DEBUG:
command.extend(["-d", "2"])
return command