# -*- coding: utf-8 -*-
#
# Copyright (C) 2013 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 Dynamips hypervisor and starts/stops the associated Dynamips process.
"""
import os
import time
import subprocess
import tempfile
from .dynamips_hypervisor import DynamipsHypervisor
from .dynamips_error import DynamipsError
import logging
log = logging.getLogger(__name__)
class Hypervisor(DynamipsHypervisor):
"""
Hypervisor.
:param path: path to Dynamips executable
:param working_dir: working directory
:param port: port for this hypervisor
:param host: host/address for this hypervisor
"""
_instance_count = 0
def __init__(self, path, working_dir, host, port):
DynamipsHypervisor.__init__(self, working_dir, host, port)
# create an unique ID
self._id = Hypervisor._instance_count
Hypervisor._instance_count += 1
self._path = path
self._command = []
self._process = None
self._stdout_file = ""
self._started = False
# settings used the load-balance hypervisors
# (for the hypervisor manager)
self._memory_load = 0
self._ios_image_ref = ""
@property
def id(self):
"""
Returns the unique ID for this hypervisor.
:returns: id (integer)
"""
return(self._id)
@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 Dynamips executable.
:returns: path to Dynamips
"""
return(self._path)
@path.setter
def path(self, path):
"""
Sets the path to the Dynamips executable.
:param path: path to Dynamips
"""
self._path = path
@property
def port(self):
"""
Returns the port used to start the Dynamips hypervisor.
:returns: port number (integer)
"""
return(self._port)
@port.setter
def port(self, port):
"""
Sets the port used to start the Dynamips hypervisor.
:param port: port number (integer)
"""
self._port = port
@property
def host(self):
"""
Returns the host (binding) used to start the Dynamips hypervisor.
:returns: host/address (string)
"""
return(self._host)
@host.setter
def host(self, host):
"""
Sets the host (binding) used to start the Dynamips hypervisor.
:param host: host/address (string)
"""
self._host = host
@property
def image_ref(self):
"""
Returns the reference IOS image name
(used by the hypervisor manager for load-balancing purposes).
:returns: image reference name
"""
return self._ios_image_ref
@image_ref.setter
def image_ref(self, ios_image_name):
"""
Sets the reference IOS image name
(used by the hypervisor manager for load-balancing purposes).
:param ios_image_name: image reference name
"""
self._ios_image_ref = ios_image_name
def increase_memory_load(self, memory):
"""
Increases the memory load of this hypervisor.
(used by the hypervisor manager for load-balancing purposes).
:param memory: amount of RAM (integer)
"""
self._memory_load += memory
def decrease_memory_load(self, memory):
"""
Decreases the memory load of this hypervisor.
(used by the hypervisor manager for load-balancing purposes).
:param memory: amount of RAM (integer)
"""
self._memory_load -= memory
@property
def memory_load(self):
"""
Returns the memory load of this hypervisor.
(used by the hypervisor manager for load-balancing purposes).
:returns: amount of RAM (integer)
"""
return self._memory_load
def start(self):
"""
Starts the Dynamips hypervisor process.
"""
self._command = self._build_command()
try:
log.info("starting Dynamips: {}".format(self._command))
with tempfile.NamedTemporaryFile(delete=False) as fd:
self._stdout_file = fd.name
log.info("Dynamips process logging to {}".format(fd.name))
self._process = subprocess.Popen(self._command,
stdout=fd,
stderr=subprocess.STDOUT,
cwd=self._working_dir)
log.info("Dynamips started PID={}".format(self._process.pid))
self._started = True
except OSError as e:
log.error("could not start Dynamips: {}".format(e))
raise DynamipsError("could not start Dynamips: {}".format(e))
def stop(self):
"""
Stops the Dynamips hypervisor process.
"""
if self.is_running():
DynamipsHypervisor.stop(self)
log.info("stopping Dynamips PID={}".format(self._process.pid))
try:
# give some time for the hypervisor to properly stop.
# time to delete UNIX NIOs for instance.
time.sleep(0.01)
self._process.terminate()
self._process.wait(1)
except subprocess.TimeoutExpired:
self._process.kill()
if self._process.poll() == None:
log.warn("Dynamips process {} is still running".format(self._process.pid))
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 Dynamips log file: {}".format(e))
self._started = False
def read_stdout(self):
"""
Reads the standard output of the Dynamips 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) as file:
output = file.read()
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.poll() == None:
return True
return False
def _build_command(self):
"""
Command to start the Dynamips hypervisor process.
(to be passed to subprocess.Popen())
"""
command = [self._path]
command.extend(["-N1"]) # use instance IDs for filenames
command.extend(["-l", "dynamips_log_{}.txt".format(self._port)]) # log file
if self._host != "0.0.0.0" and self._host != "::":
command.extend(["-H", "{}:{}".format(self._host, self._port)])
else:
command.extend(["-H", str(self._port)])
return command