#!/usr/bin/python
#######
# Fencing agent for qemu, written by Matthew Ife. Matthew.Ife@ukfast.co.uk 2009
# Licensed as GPL Version 2
######

import os, sys, re
import getopt
import libvirt

def virt_act(ip, vm, action):
	# attempt to connect to the hypervisor first
	try:
		conn = libvirt.open('qemu+tcp://'+ip+'/system')
	except libvirt.libvirtError, err:
		print "TherevirDomainLookupByName was a problem connecting to the hypervisor:",
		print str(err)
		sys.exit(2)

	# check the vm exists and get its infomation
	try:
		id = conn.lookupByName(vm)
	except libvirt.libvirtError, err:
		print "There was a problem finding the domain specified:",
		print str(err)
		sys.exit(2)

	# perform some form of action. Thanks to libvirt this is pretty simple
	try:
		state = id.info()[0]
	except libvirt.libvirtError, err:
		print "There was a problem getting the domain status:",
		print str(err)
		sys.exit(2)

	if action == "status":
		if state in (1, 2, 4, 6): # offline states
			# since a number of states are bad (paused and crashes) they are just considered online
			# for a worst case scenario
			print "on"

		elif state in (0, 3, 5): # online states
			# Note 0 is actually "no state" we might not want this here
			print "off"

	elif action == "on":
		try:
			id.create()
		except libvirt.libvirtError, err:
			print "A problem occured bringing the node online:"+str(err)
			sys.exit(2)


	elif action == "off":
		try:
			id.destroy()
		except libvirt.libvirtError, err:
			pass

	
	elif action == "reboot":
		try:
			id.destroy()
		except libvirt.libvirtError, err:
			# we dont care if the node is down already
			pass

		try:
			id.create()
		except libvirt.libvirtError, err:
			print "A problem occured bringing the node online:"+str(err)
			sys.exit(2)

	return






def print_help():
	print """
Usage:
   fence_qemu [options]
   -o   --action      The action you want to take currently supports;
			 off, on, status, reboot
   -n   --name	 The name of the virtual machine you wish to act upon
   -a   --ip	   The IP or Host of the hypervisor to connect to
"""
	sys.exit(0)






def main():
	f = open('/tmp/log','a')
	if len(sys.argv) > 1:
		try:
			opts, args = getopt.getopt(sys.argv[1:], 'o:n:a:h', [ "action", "name", "ipaddr", "help" ])
		except getopt.GetoptError, err:
			print "You did not specify the right args"
			print str(err)

		for options, args in opts:
			if options in ('-o', '--action'):
				action = args
	
			elif options in ('-n', '--name'):
				vm = args
	
			elif options in ('-a', '--ipaddr'):
				ip = args
			elif options in ('-h', '--help'):
				print_help()

	else:
		for opt in sys.stdin.readlines():
			if re.match("#",opt) or re.match("^$",opt):
				continue
			(options,args) = opt.split("=")

			if options == "action":
				action = args.rstrip()

			elif options in ("port","name"):
				vm = args.rstrip()

			elif options == "ipaddr":
				ip = args.rstrip()


	try:
		virt_act(ip, vm, action)
	except NameError, err:
		print "You did not supply the required number of parameters."
		print str(err)
		sys.exit(1)


if __name__ == "__main__":
	main()