#!/usr/bin/python
#
# xen-stat.py - Displays stats about Xen domains (HVM and PVM)
#
# 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
# 2 of the License, or (at your option) any later version.
#
# Diego Woitasen, <diegows@xxxxxxxxxxxx>
#
# Tested with Xen 3.1.x
# 
# The output displays:
#
# -CPU time
# -Memory assigned
# -Network: Bytes transmitted and received.
# -Disks: Sectors read and written
#
# Limitations:
#
# -Needs this patch to get HVM networking stats:
# http://xenbits.xensource.com/xen-unstable.hg?raw-diff/3ab6635f783d/tools/python/xen/xend/image.py
# -For 'file:' virtual block devices, it shows information about the
# the real device where the file resides. Works for me :)
#

import sys
import os
sys.path.append('/usr/lib/python')
from xen.xm.XenAPI import *

def net_stats(dom_name):
	dev_file = open('/proc/net/dev')
	lines = dev_file.readlines()

	if domains_type[dom_name] == 'hvm':
		dev_prefix = 'tap%d.' % (domains_id[dom_name])
	else:
		dev_prefix = 'vif%d.' % (domains_id[dom_name])

	net_tx = 0
	net_rx = 0
	for line in lines:
		if line.startswith(dev_prefix):
			line = line[line.find(':') + 1:]
			fields = line.split()
			net_rx += int(fields[0])
			net_tx += int(fields[8])

	return net_tx, net_rx

def disk_stats(dom_name):
	info = domains_info[dom_name]

	disks = []
	for i in info:
		if i[0] == 'device' and i[1][0] == 'vbd':
			disk = i[1][1][1]
			disk = disk.split(':')
			disks.append(disk)

	vbd_wr = 0
	vbd_rr = 0
	for disk in disks:
		if disk[0] == 'file':
			minor = os.minor(os.stat(disk[1]).st_dev)
		elif disk[0] == 'phy':
			devname = os.readlink(disk[1])
			minor = os.minor(os.stat(devname).st_rdev)
		else:
			continue

		statsfile = '/sys/block/dm-%s/stat' % (str(minor))
		stats = open(statsfile).readline().split()
		vbd_rr += int(stats[2])
		vbd_wr += int(stats[6])

	return vbd_wr, vbd_rr

def info_get(dom_name, param):
	for i in domains_info[dom_name]:
		if i[0] == param:
			return i[1]

def cpu_stat(dom_name):
	return info_get(dom_name, 'cpu_time')

def mem_stat(dom_name):
	return info_get(dom_name, 'memory')

#xend connection
xmlsession = Session('http://localhost:8006')
xend = xmlsession.xend

domains = xend.domains_with_state(True, 'all', True)

#domain type indexed by domain name
domains_type = {}
domains_info = {}
domains_id = {}
for dom in domains:
	type = 'pvm'
	for info in dom:
		if info[0] == 'image':
			for i in info[1]:
				if i == 'hvm':
					type = 'hvm'
		if info[0] == 'domid':
			id = info[1]
		if info[0] == 'name':
			name = info[1]

	if id == 0:
		continue
	domains_type[name] = type;
	domains_info[name] = dom
	domains_id[name] = id

#print domains_type
#print domains_info
#print domains_id

for dom_name, dom_info in domains_info.items():
	cpu = cpu_stat(dom_name)
	mem = mem_stat(dom_name)
	net_tx, net_rx = net_stats(dom_name)
	vbd_wr, vbd_rr = disk_stats(dom_name)

	print 'NAME=', dom_name
	print 'CPU=', cpu
	print 'MEM=', mem
	print 'NET_TX=', net_tx
	print 'NET_RX=', net_rx
	print 'VBD_WR=', vbd_wr
	print 'VBD_RR=', vbd_rr
	print