Munin contributed plugins

#!/usr/bin/python3

# vim: set fileencoding=utf-8

#

# Munin plugin to show the network I/O per vm

#

# Copyright Igor Borodikhin

#

# 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 Network I/O

graph_vlabel Bytes rx(-)/tx(+) per second

graph_category Virtualization

graph_info This graph shows the network I/O of the virtual machines

graph_args --base 1024

    """

    print(base_config)

    for vm in vm_names:

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

        print("%s_in.type COUNTER" % vm)

        print("%s_in.min 0" % vm)

        print("%s_in.draw LINE2" % vm)

        print("%s_out.negative %s_in" % (vm, vm))

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

        print("%s_out.type COUNTER" % vm)

        print("%s_out.min 0" % vm)

        print("%s_out.draw LINE2" % 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)

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

def fetch(vms):

    """ Fetch values for a list of pids

    @param dictionnary {kvm_pid: cleaned vm name}

    """

    res = {}

    for pid in vms:

        tap = get_vm_mac(pid)

        try:

            f = open("/proc/net/dev", "r")

            for line in f.readlines():

                if tap in line:

                    print("%s_in.value %s" % (vms[pid], line.split()[1]))

                    print("%s_out.value %s" % (vms[pid], line.split()[9]))

                    break

        except Exception as inst:

            print(inst)

            continue

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 dictionnary 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"^.*-name\x00([a-zA-Z0-9.-_-]*)\x00\-.*$",r"\1", cmdline.readline()))

    return result

def get_vm_mac(pid):

    """Find and clean vm names from pids

    @return the mac address for a specified pid

    """

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

    line = cmdline.readline()

    mac = re.sub(r"^.*ifname=(tap[^,]+),.*$",r"\1", line)

    return mac

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)

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