Modify KVM VM (stopped) network setting using libguestfs

edit-vm-network-setting.py

#!/bin/env python
import sys
import libvirt
import guestfs
from lxml import etree
 
if (len(sys.argv) != 4):
    sys.exit('Usage: # sudo python %s domain eth0 eth1' % sys.argv[0])
 
domain = sys.argv[1]
ip0 = sys.argv[2]
ip1 = sys.argv[3]
 
uri = 'qemu:///system'  #kvm
conn = libvirt.open(uri)
 
# check vm is exist
try:
    vm = conn.lookupByName(domain)
except libvirt.libvirtError:
    sys.exit('Domain not found: ' + domain)
 
# check vm is stoped
if (vm.isActive() != 0):
    sys.exit('Domain is active: ' + domain)
 
# get variables from xml
devices = etree.fromstring(vm.XMLDesc(0)).findall('devices')[0]
 
disk = devices.find('disk').find('source').attrib["file"]  # disk image
 
mac0 = ''  # eth0 mac address
mac1 = ''  # eth1 mac address
for interface in devices.findall('interface'):
    bridge = interface.find('source').attrib["bridge"]
    mac = interface.find('mac').attrib["address"]
    if (bridge == 'br0'):
        mac0 = mac
    elif (bridge == 'virbr0'):
        mac1 = mac
 
# new configuration
ifcfg='''DEVICE=%s
BOOTPROTO=static
HWADDR=%s
IPADDR=%s
NETMASK=255.255.255.0
ONBOOT=yes'''
ifcfg0 = ifcfg % ('eth0', mac0, ip0)
ifcfg1 = ifcfg % ('eth1', mac1, ip1)
print 'New network configuration'
print '---------------------------'
print ifcfg0
print '---------------------------'
print ifcfg1
print '---------------------------'
 
# write variables to vm directly with libguestfs
guest = guestfs.GuestFS()
guest.add_drive(disk)
guest.launch()
guest.mount('/dev/mapper/VolGroup00-LogVol00', '/')
guest.write_file('/etc/sysconfig/network-scripts/ifcfg-eth0', ifcfg0, 0)
guest.write_file('/etc/sysconfig/network-scripts/ifcfg-eth1', ifcfg1, 0)
guest.sync()
guest.umount_all()
 
print 'Finish'