openstack 调用API 实现云主机的IO 控制，CGroup 策略

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (c) 2011 X.commerce, a business unit of eBay Inc.
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.
#    Single virtual machine io limit , reader 70/MB , writer 50/MB
"""
    curl -d '{"auth": {"tenantName": "admin", "passwordCredentials": {"username": "admin", "password": "admin"}}}' -H "Content-type: application/json" http://127.0.0.1:35357/v2.0/tokens | python -m json.tool
    curl -v -d '{"ioctlAction": {"instance_name":"instance-0000000c","limit_reader":"40MB","limit_writer":"60MB"}}' -i http://127.0.0.1:8774/v2/ba5a6a86a8224a70ba0ffde747d8a724/servers/e6b9cae7-8732-405d-9aaf-575643b4bbef/action -X POST -H "X-Auth-Project-Id: ba5a6a86a8224a70ba0ffde747d8a724" -H "Accept: application/json" -H "X-Auth-Token: 6f0c37595f384fd4a18766825cf49013" -H "Content-Type: application/json"
"""
import time,sys,os,libvirt,traceback,re,subprocess,json
from nova import log as logging
from nova import flags
from nova.periodic.blkio  import config
from nova import utils
from nova.periodic.blkio import utils as blkio_utils
FLAGS = flags.FLAGS
LOG = logging.getLogger(__name__)
class ActionIoctl(object):
    def __init__(self,instance_name,limit_reader,limit_writer):
        self.conn = libvirt.open(None)
        self.limitReader = int(limit_reader[0:-2])
        self.limitWriter = int(limit_writer[0:-2])
        self.name = instance_name
        self.path = FLAGS.instances_path
    def diskDeviceNum(self,disk):
        """ Func info:  Returns the number of hard disk,other is 8:0 """
        if disk == '/dev/sda1' or disk == '/dev/hda1' or disk[:-1] == '/dev/sda' or disk[:-1] == '/dev/hda':
            return '8:0'
        elif disk == '/dev/sdb1' or disk == '/dev/hdb1' or disk[:-1] == '/dev/sdb' or disk[:-1] == '/dev/hdb':
            return '8:16'
        elif disk == '/dev/sdc1' or disk == '/dev/hdc1' or disk[:-1] == '/dev/sdc' or disk[:-1] == '/dev/hdc':
            return '8:32'
        elif disk == '/dev/sdd1' or disk == '/dev/hdd1' or disk[:-1] == '/dev/sdd' or disk[:-1] == '/dev/hdd':
            return '8:48'
        else:
            return '8:16'
    def vmsPIDall(self):
        """ Getting all vm port, return to """
        pid = list()
        try:
            cmds = """ps -ef |grep uuid|grep -v grep |awk '{print $2}'"""
            pid=os.popen(cmds).readlines()
            return pid
        except Exception,e:
            LOG.error(_('[-william-] Error %s'%e))
            return
    def cgroupPath(self):
        '''
        Func info : Return Cgroup path ,Because the system is not the same,
                    the Cgroup path is different also.
                    By default, have RedHat, Centos, Ubuntu  linux  ...
            osType : The current system version , And return to ...
            Cpath  : Cgroup path
        '''
        osType = open('/etc/issue').readlines()
        for i in osType:
            if re.match('Ubuntu',i):
                Cpath = '/sys/fs/cgroup/'
                return Cpath
            elif re.match('CentOS',i):
                Cpath = '/cgroup/'
                return Cpath
            elif re.match('Red Hat',i):
                Cpath = '/cgroup/'
                return Cpath
            else:
                return '/sys/fs/cgroup/'
    def exeCmd(self,cmds):
        ''' Perform system command '''
        LOG.info(_('exeCmd  %s'%cmds))
        try:
            exec_process = subprocess.Popen(cmds,
                            stdin = subprocess.PIPE,
                            stdout = subprocess.PIPE,
                            stderr = subprocess.PIPE,
                            shell = True)
            exec_process.wait()
            rest = exec_process.stdout.read()
            err = exec_process.stderr.read()
            if err == '':
                return rest
            else:
                LOG.error(_('[-william-] return values is null'))
        except Exception,e:
            LOG.error(_('[-william-] Error %s') %e)
            return
    ''' Geting vmName name  and pid '''
    def get_vm_pid(self,name):
        pid = self.conn.listDomainsID()
        try:
            pid = os.popen("""ps -ef |grep %s |grep -v grep |awk '{print $2}'""" %name).readlines()
            return int(pid[0])
        except:
            LOG.error(_('[-william-] Error %s' \
                                        %traceback.format_exc()))
            return
    def _vm_pids(self):
        try:
            return os.popen('pidof kvm').read().split()
        except:
            return
    def work(self):
        """
        Func info :  working func ................
        Cpath : is _Cpath function return values ...
        path :  The current virtual machine IMG file path
        vm_count: All of the current node number of virtual machines
        size :  Limit size
        mountInfo : mounting point
        """
        Cpath = self.cgroupPath()
        vm_pid = self.get_vm_pid(self.name)
        LOG.info(_('[- william -] %s , %s' %(self.name,vm_pid)))
        r_size = self.limitReader * 1000 * 1000
        w_size = self.limitWriter * 1000 * 1000
        device = blkio_utils.instance_path(self.path)
        diskDeviceNum = self.diskDeviceNum(device)
        vmTaskPath = "%s/blkio/%s"%(Cpath,self.name)
        utils.execute("mkdir","-p",vmTaskPath,run_as_root=True)
        utils.execute("tee" , "%s/blkio.throttle.read_bps_device"%vmTaskPath,\
                      process_input = "%s %s"%(diskDeviceNum,r_size),\
                      run_as_root=True)
        utils.execute("tee" , "%s/blkio.throttle.write_bps_device"%vmTaskPath, \
                      process_input = "%s %s"%(diskDeviceNum,w_size) ,\
                      run_as_root=True)
        LOG.info(_(""" [-william-] echo  '%s, %s, %s , %s , %s ' write oK """
                    %(self.path , device, diskDeviceNum, w_size, r_size)))
        utils.execute('tee', '%s/tasks'%vmTaskPath,\
                      process_input= str(vm_pid) ,\
                      run_as_root=True)
        LOG.info(_('[- william-] append pid %s in task' %vm_pid))
if __name__ == "__main__":
    sc = ActionIoctl('instance-0000000c','40MB','30MB')
    sc.work()