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#!/usr/bin/env python
import sys
import grp
import pwd
import os
import libvirt
import ConfigParser
import subprocess
import shutil
import distutils.spawn
import platform
# this does a very basic test to see if the required packages
# are installed, extend list as required
def checkPackages():
sys_ok = True
check_apps = [ "virsh", "qemu-system-x86_64", "libvirtd" ]
for app in check_apps:
if distutils.spawn.find_executable(app) == None:
print( "Missing: " + app)
sys_ok = False
if not sys_ok:
print("The required libvirt/qemu packages are missing...")
distro = platform.dist()[0]
if distro == "debian" or distro == "Ubuntu":
print( "This appears to be a Debian/Ubuntu distribution\nPlease install " +
"packages like libvirt-bin, qemu-system-x86,..." )
elif distro == "redhat" or distro == "fedora":
print( "This appears to be a Redhat/Fedora distribution\nPlease install " +
"packages like libvirt-client, libvirt-daemon, qemu-system-x86, ..." )
exit(1)
return
def networkInterfaces():
ifaces = []
for line in open('/proc/net/dev', 'r'):
if_info = line.split(":", 1)
if len(if_info) > 1:
ifaces.append( if_info[0].strip() )
return ifaces
def destroyNetwork(conn, network_name):
networks = conn.listNetworks() + conn.listDefinedNetworks()
if network_name in networks:
try:
nw = conn.networkLookupByName(network_name)
if nw.isActive():
nw.destroy()
nw.undefine()
except:
print( "Failed to destroy network: %s" % network_name )
exit( 1 )
def restartDomain(conn, domain_name):
try:
domain = conn.lookupByName(domain_name)
except:
print( "restartDomain: Warning domain " + domain_name + " doesn't exist." )
return
if domain.isActive():
domain.reboot()
def destroyDomain(conn, auto_destroy, domain_name):
try:
domain = conn.lookupByName(domain_name)
except:
return
if domain.isActive():
if auto_destroy:
print( "Auto destroy enabled, destroying old instance of domain %s" % domain_name )
domain.destroy()
else:
print( "Domain %s is active, abort..." % domain_name )
print( "To stop: virsh -c %s destroy %s " % ( uri , domain_name ) )
exit(0)
domain.undefine()
def startDomain(conn, auto_destroy, domain_name, xml_desc):
print( "Starting %s...\n%s" % ( domain_name, xml_desc ) )
destroyDomain(conn, auto_destroy, domain_name)
try:
conn.defineXML(xml_desc)
domain = conn.lookupByName(domain_name)
domain.create()
print( "Starting domain %s..." % domain_name )
print( "To connect to the console: virsh -c %s console %s" % ( uri, domain_name ) )
print( "To stop: virsh -c %s destroy %s" % ( uri, domain_name ) )
except Exception as e:
print( e )
exit(1)
def make_nw_spec(network_name, bridge_nw_interface, network, auto_assign_ip):
spec = '<network>'
spec += '<name>' + network_name + '</name>'
spec += '<bridge name="' + bridge_nw_interface + '"/>'
spec += '<forward/>'
spec += '<ip address="' + network + '" netmask="255.255.255.0">'
if auto_assign_ip:
nw_parts = network.split('.')
nw_parts[-1] = "2"
start_dhcp = '.'.join(nw_parts)
nw_parts[-1] = "254"
end_dhcp = '.'.join(nw_parts)
spec += '<dhcp>'
spec += '<range start="' + start_dhcp + '" end="' + end_dhcp + '"/>'
spec += '</dhcp>'
spec += '</ip>'
spec += '</network>'
return spec
def make_spec(name, network, kernel, disk, bridge_nw_interface, emulator, auto_assign_ip, ip):
if not os.path.exists(kernel):
print( "Kernel image %s does not exist!" % kernel )
exit(1)
if not os.path.exists(disk):
print( "Disk %s does not exist!" % disk )
exit(1)
if auto_assign_ip:
ip_spec = 'dhcp'
else:
ip_spec = ip + '::' + network + ':255.255.255.0:' + name + ':eth0:off'
spec = '<domain type=\'kvm\'>'
spec += ' <name>' + name + '</name>'
spec += ' <memory>4096000</memory>'
spec += ' <currentMemory>4096000</currentMemory>'
spec += ' <vcpu cpuset=\'1\'>1</vcpu>'
spec += ' <cpu>'
spec += ' <model>kvm64</model>'
spec += ' </cpu>'
spec += ' <os>'
spec += ' <type arch=\'x86_64\' machine=\'pc\'>hvm</type>'
spec += ' <kernel>' + kernel + '</kernel>'
spec += ' <boot dev=\'hd\'/>'
spec += ' <cmdline>root=/dev/vda rw console=ttyS0 ip=' + ip_spec + '</cmdline>'
spec += ' </os>'
spec += ' <features>'
spec += ' <acpi/>'
spec += ' <apic/>'
spec += ' <pae/>'
spec += ' </features>'
spec += ' <clock offset=\'utc\'/>'
spec += ' <on_poweroff>destroy</on_poweroff>'
# spec += ' <on_reboot>destroy</on_reboot>'
spec += ' <on_crash>destroy</on_crash>'
spec += ' <devices>'
spec += ' <emulator>' + emulator + '</emulator>'
spec += ' <disk type=\'file\' device=\'disk\'>'
spec += ' <source file=\'' + disk + '\'/>'
spec += ' <target dev=\'vda\' bus=\'virtio\'/>'
spec += ' </disk>'
spec += ' <interface type=\'bridge\'>'
spec += ' <source bridge=\'' + bridge_nw_interface + '\'/>'
spec += ' <model type=\'virtio\' />'
spec += ' </interface>'
spec += ' <serial type=\'pty\'>'
spec += ' <target port=\'0\'/>'
spec += ' <alias name=\'serial0\'/>'
spec += ' </serial>'
spec += ' <console type=\'pty\'>'
spec += ' <target type=\'serial\' port=\'0\'/>'
spec += ' <alias name=\'serial0\'/>'
spec += ' </console>'
spec += ' </devices>'
spec += '</domain>'
return spec
def getConfig(config, section, key):
try:
return os.path.expandvars(config.get(section, key))
except:
print( "Configuration file error! Missing item (section: %s, key: %s)" % ( section, key ) )
exit(1)
# does the user have access to libvirt?
eligible_groups = [ "libvirt", "libvirtd" ]
eligible_user = False
euid = os.geteuid()
if euid == 0:
eligible_user = True
else:
username = pwd.getpwuid(euid)[0]
groups = [g.gr_name for g in grp.getgrall() if username in g.gr_mem]
for v in eligible_groups:
if v in groups:
eligible_user = True
checkPackages()
if not eligible_user:
sys.stderr.write("You need to be the 'root' user or in group [" + '|'.join(eligible_groups) + "] to run this script.\n")
exit(1)
if len(sys.argv) != 3:
sys.stderr.write("Usage: "+sys.argv[0]+" [config file] [start|stop|restart]\n")
sys.exit(1)
if not os.path.exists(sys.argv[1]):
sys.stderr.write("Error: config file \"" + sys.argv[1] + "\" was not found!\n")
sys.exit(1)
command = sys.argv[2]
command_options = ["start", "stop", "restart"]
if not command in command_options:
sys.stderr.write("Usage: "+sys.argv[0]+" [config file] [start|stop|restart]\n")
sys.exit(1)
Config = ConfigParser.ConfigParser()
Config.read(sys.argv[1])
network_addr = getConfig(Config, "main", "network")
getConfig(Config, "main", "auto_destroy")
auto_destroy = Config.getboolean("main", "auto_destroy")
getConfig(Config, "main", "auto_assign_ip")
auto_assign_ip = Config.getboolean("main", "auto_assign_ip")
network_name = 'ops_default'
uri = 'qemu:///system'
# Connect to libvirt
conn = libvirt.open(uri)
if conn is None:
print( "Failed to open connection to the hypervisor" )
exit(1)
if command == "start":
destroyNetwork(conn, network_name)
# Change the default bridge device from virbr0 to virbr%d.
# This will make libvirt try virbr0, virbr1, etc. until it finds a free one.
cnt = 0
ifaces = networkInterfaces()
found_virbr = False
while found_virbr == False:
if cnt > 254:
print( "Giving up on looking for a free virbr network interface!" )
exit(1)
bridge_nw_interface = 'virbr' + str(cnt)
if bridge_nw_interface not in ifaces:
print( "bridge_nw_interface: %s" % bridge_nw_interface )
network_spec = make_nw_spec(network_name, bridge_nw_interface, network_addr, auto_assign_ip)
try:
conn.networkDefineXML(network_spec)
nw = conn.networkLookupByName(network_name)
nw.create()
found_virbr = True
except:
print( "Network Name: %s" % network_name )
destroyNetwork( conn, network_name )
print( "Error creating network interface" )
cnt += 1
else:
# verify network exists
try:
nw = conn.networkLookupByName(network_name)
except:
print( "Error! Virtual network " + network_name + " is not defined!" )
exit(1)
if not nw.isActive():
print( "Error! Virtual network " + network_name + " is not running!" )
exit(1)
emulator = getConfig(Config, "main", "emulator")
if not os.path.exists(emulator):
print( "Emulator %s does not exist!" % emulator )
exit(1)
controller_name = 'controller'
if command == "start":
# Define the controller xml
controller_kernel = getConfig(Config, "controller", "kernel")
controller_disk = getConfig(Config, "controller", "disk")
controller_ip = None
if not auto_assign_ip:
controller_ip = getConfig(Config, "controller", "ip")
controller_spec = make_spec(controller_name, network_addr, controller_kernel,
controller_disk, bridge_nw_interface, emulator,
auto_assign_ip, controller_ip)
# Now that network is setup let's actually run the virtual images
startDomain(conn, auto_destroy, controller_name, controller_spec)
elif command == "stop":
destroyDomain(conn, True, controller_name)
elif command == "restart":
restartDomain(conn, controller_name)
for i in Config.sections():
if i.startswith("compute"):
if command == "start":
# Define the compute xml
kernel = getConfig(Config, i, "kernel")
disk = getConfig(Config, i, "disk")
compute_ip = None
if not auto_assign_ip:
compute_ip = getConfig(Config, i, "ip")
spec = make_spec(i, network_addr, kernel, disk, bridge_nw_interface,
emulator, auto_assign_ip, compute_ip)
startDomain(conn, auto_destroy, i, spec)
elif command == "stop":
destroyDomain(conn, True, i)
elif command == "restart":
restartDomain(conn, i)
conn.close()
|
