Munin contributed plugins

#!/usr/bin/env python3

# -*- coding: utf-8 -*-

# vim: set fileencoding=utf-8

#

# Munin plugin to show amount of memory used by vm

#

# Copyright Maxence Dunnewind, Rodolphe Quiédeville, Adrien Pujol

#

# License : GPLv3

#

# parsed environment variables:

# vmsuffix: part of vm name to be removed

#

#%# capabilities=autoconf

#%# family=contrib

import re, os, sys

from subprocess import Popen, PIPE

def config(vm_names):

    ''' Print the plugin's config

    @param vm_names : a list of "cleaned" vms' name

    '''

    base_config = """graph_title KVM Virtual Machine Memory usage

graph_vlabel Bytes

graph_category virtualization

graph_info This graph shows the current amount of memory used by virtual machines

graph_args --base 1024 -l 0"""

    print(base_config)

    for vm in vm_names:

        print("%s_mem.label %s" % (vm, vm))

        print("%s_mem.type GAUGE" % vm)

        print("%s_mem.draw %s" % (vm, "AREASTACK"))

        print("%s_mem.info memory used by virtual machine %s" % (vm, vm))

def clean_vm_name(vm_name):

    ''' Replace all special chars

    @param vm_name : a vm's name

    @return cleaned vm's name

    '''

    # suffix part defined in conf

    suffix = os.getenv('vmsuffix')

    if suffix:

        vm_name = re.sub(suffix,'',vm_name)

    # proxmox uses kvm with -name parameter

    parts = vm_name.split('\x00')

    if (parts[0].endswith('kvm')):

        try:

            return parts[parts.index('-name')+1]

        except ValueError:

            pass

    return re.sub(r"[^a-zA-Z0-9_]", "_", vm_name)

def fetch(vms):

    ''' Fetch values for a list of pids

    @param dictionary {kvm_pid: cleaned vm name}

    '''

    res = {}

    for pid in vms:

        try:

            cmdline = open("/proc/%s/cmdline" % pid, "r")

            amount = re.sub(r"^.*-m\x00(.*)\x00-smp.*$",r"\1", cmdline.readline())

            amount = int(amount) * 1024 * 1024

            print("%s_mem.value %s" % (vms[pid], amount))

        except:

            cmdline = open("/proc/%s/cmdline" % pid, "r")

            amount = re.sub(r"^.*-m\x00(\d+).*$",r"\1", cmdline.readline())

            amount = int(amount) * 1024 * 1024

            print("%s_mem.value %s" % (vms[pid], amount))

def detect_kvm():

    ''' Check if kvm is installed

    '''

    kvm = Popen("which kvm", shell=True, stdout=PIPE)

    kvm.communicate()

    return not bool(kvm.returncode)

def find_vm_names(pids):

    '''Find and clean vm names from pids

    @return a dictionary of {pids : cleaned vm name}

    '''

    result = {}

    for pid in pids:

        cmdline = open("/proc/%s/cmdline" % pid, "r")

        result[pid] = clean_vm_name(re.sub(r"^.*guest=([a-zA-Z0-9.-_-]*).*$",r"\1", cmdline.readline()))

    return result

def list_pids():

    ''' Find the pid of kvm processes

    @return a list of pids from running kvm

    '''

    pid = Popen("pidof qemu-kvm qemu-system-x86_64 kvm", shell=True, stdout=PIPE, text=True)

    return pid.communicate()[0].split()

if __name__ == "__main__":

    if len(sys.argv) > 1:

        if sys.argv[1] in ['autoconf', 'detect']:

            if detect_kvm():

                print("yes")

            else:

                print("no")

        elif sys.argv[1] == "config":

            config(find_vm_names(list_pids()).values())

        else:

            fetch(find_vm_names(list_pids()))

    else:

        fetch(find_vm_names(list_pids()))