Monit installation

Installation

Sur Debian

apt-get install monit

Dans /etc/monit/monitrc, décommenter :

set daemon  120 # NOTE POUR DEBIAN : c'est le paramètre de /etc/default/monit CHECK_INTERVAL qui est prioritaire
                # (lancement du démon avec "-d" dans l'init.d), c'est lui qu'il faut donc modifier !
set logfile syslog facility log_daemon
set mailserver   localhost             # primary mailserver

Modifier le format du mail :

set mail-format {
    From: monit-<nom du serveur>@systea.net
    Subject: $EVENT $SERVICE
    Message: $DATE
    $SERVICE : $EVENT
    $DESCRIPTION
    Monit $ACTION : $SERVICE
}

Donner le destinataire :

set alert <administrateur>@systea.net                       # receive all alerts

Eventuellement, ouvrir le "embedded webserver" au localhost pour au moins pouvoir lancer un "monit status" ou "monit summary" (voir plus bas pour redirection php si APACHE installé):

set httpd port 2812 and
    use address localhost  # only accept connection from localhost
    allow localhost        # allow localhost to connect to the server and

Note S'il ny a pas d'Apache, ouvrir le port 2812 et configurer monit en SSL autonome :

set httpd port 2812 and
   SSL Enable 
   PEMFILE /etc/apache2/ssl/apache.pem
   allow admin:<mot de passe admin>      # require user 'admin' with password

Note2 L'ouverture du port 2812 peut être un trou de sécurité. Ne l'ouvrir qu'en connaissance de cause.

Vérifier que :

include /etc/monit/monit.d/*

est décommenté (ajouter le "monit" au milieu, il n'y est pas par défaut).
Créer le répertoire au besoin.

Comme indiqué dans le commentaire de l'option "set daemon", il faut aussi modifier /etc/default/monit, mais uniquement si on veut un interval différent de 180 secondes (valeur par défaut). On en profitera pour mettre "startup" à 1, sinon Monit ne démarre pas en tâche de fond :

# Defaults for monit initscript
# sourced by /etc/init.d/monit
# installed at /etc/default/monit by maintainer scripts
# Fredrik Steen <stone@debian.org>

# You must set this variable to for monit to start
startup=1

# To change the intervals which monit should run uncomment
# and change this variable.
CHECK_INTERVALS=120

Sur CentOS / RedHat

Récupérer la dernière version de paquet sur dag.wieers.com (CentOS4 = RHEL4)

# wget http://dag.wieers.com/rpm/packages/monit/monit-4.9-2.el4.rf.i386.rpm

Installer :

# rpm -i monit-4.9-2.el4.rf.i386.rpm

Attention, le fichier de conf est /etc/monit.conf. Le répertoire /etc/monit.d est déjà créé. Il n'y a pas de fichier /etc/default/monit.

Modifier monit.conf comme indiqué pour la Debian.

Configuration des services

Exemple de fichier de config /etc/monit/monit.d/serveur.systea.net, type DEBIAN/ISPConfig, surveillance locale :

###############################################################################
## serveur.systea.net local
###############################################################################
#
check system serveur.systea.net
    if loadavg (1min) > 6 then alert
    if loadavg (5min) > 4 then exec "/root/bin/top.sh LoadAvg5mn"
    if memory usage > 85% then exec "/root/bin/top.sh Memory"
    if cpu usage (user) > 70% for 3 cycles then exec "/root/bin/top.sh CPUuser"
    if cpu usage (system) > 50% for 3 cycles then exec "/root/bin/top.sh CPUsys"
    if cpu usage (wait) > 60% for 3 cycles then exec "/root/bin/top.sh CPUwait"
check process apache2 with pidfile /var/run/apache2.pid
    start program = "/etc/init.d/apache2 start"
    stop program  = "/etc/init.d/apache2 stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 80 then restart
check process proftpd1 with pidfile /var/run/proftpd.pid
    start program = "/etc/init.d/proftpd start"
    stop program  = "/etc/init.d/proftpd stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 21 then restart
check process postfix2 with pidfile /var/spool/postfix/pid/master.pid
    start program = "/etc/init.d/postfix start"
    stop program  = "/etc/init.d//postfix stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 25 then restart
check process mysql5 with pidfile /var/run/mysqld/mysqld.pid
    start program = "/etc/init.d/mysql start"
    stop program  = "/etc/init.d/mysql stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 3306 then restart
check process postgresql7 with pidfile /var/lib/postgresql/7.4/main/postmaster.pid
    start program = "/etc/init.d/postgresql-7.4 start"
    stop program  = "/etc/init.d/postgresql-7.4 stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 5432 then restart
check device root with path /dev/sda1
    if space usage > 75% for 5 times within 15 cycles then alert
    if space usage > 90% then alert

Exemple de fichier de config /etc/monit/monit.d/serveur.ephoto.fr, type CENTOS/BlueQuartz, surveillance locale :

###############################################################################
## serveur.ephoto.fr local
###############################################################################
#
check system serveur.ephoto.fr
    if loadavg (1min) > 6 then alert
    if loadavg (5min) > 4 then exec "/opt/systools/top.sh LoadAvg5mn"
    if memory usage > 85% then exec "/opt/systools/top.sh Memory"
    if cpu usage (user) > 70% for 3 cycles then exec "/opt/systools/top.sh CPUuser"
    if cpu usage (system) > 50% for 3 cycles then exec "/opt/systools/top.sh CPUsys"
    if cpu usage (wait) > 60% for 3 cycles then exec "/opt/systools/top.sh CPUwait"
check process httpd with pidfile /var/run/httpd.pid
    start program = "/etc/init.d/httpd start"
    stop program  = "/etc/init.d/httpd stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 80 then restart
check process sendmail with pidfile /var/run/sendmail.pid
    start program = "/etc/init.d/sendmail start"
    stop program  = "/etc/init.d/sendmail stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 25 then restart
check process mysql5 with pidfile /var/run/mysqld/mysqld.pid
    start program = "/etc/init.d/mysqld start"
    stop program  = "/etc/init.d/mysqld stop"
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if failed port 3306 then restart
check device root with path /dev/mapper/VolGroup00-LogVol00
    if space usage > 75% for 5 times within 15 cycles then alert
    if space usage > 90% then alert
check device home with path /dev/mapper/VolGroup00-LogVol04
    if space usage > 75% for 5 times within 15 cycles then alert
    if space usage > 90% then alert

Fichier top.sh (version de base avec "top"):

#!/bin/bash
EVENT=$1
LOG=/root/top.log
top -d 5 -b -n 5 > $LOG
cat $LOG | mail -s "top.log serveur" <mail_admin>@systea.net

On peut aussi utiliser "ps" et "iostat" pour limiter l'affichage au minimum utile, et ajouter l'évènement passé en paramètre dans le fichier de monit.d :

#!/bin/bash
LOG=/opt/systools/top.log
if [ -f /opt/systools/top.log ]
then
   mv /opt/systools/top.log /opt/systools/top.log.0
fi
date > $LOG
iostat -c >> $LOG
for i in 1 2 3 4 5
do
   ps -eo pcpu,args | sort -r -k1 | head -5 >> $LOG
   sleep 1
done
cat $LOG | mail -s "top.log $EVENT serveur" <mail_admin>@systea.net

Exemple de /etc/monit/monit.d/serveur.systea.net sur serveur2 qui surveille serveur en remote :

###############################################################################
## serveur.systea.net remote
###############################################################################
#
check host serveur.systea.net with address 1.2.3.4
       if failed icmp type echo count 3 with timeout 10 seconds then alert

Accès au webserver de l'extérieur sans ouvrir de port supplémentaire

Apache doit être opérationnel sur la machine

Créer /var/www/monit/monit.php :

<?php
//  Copyright (C), 2004 David Fletcher, <david@megapico.co.uk>
// 
//  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.
// 
//  This program is distributed in the hope that it will be useful, but
//  WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  General Public License for more details.
// 
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software Foundation,
//  Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
//  Requires PHP, and a working webserver!
//  @author Author David Fletcher, <david@megapico.co.uk>
//  @version \$Id: monit.php,v 1.2 2004/11/20 23:53:42 hauk Exp $

//Configuration - set this to match the information in /etc/monitrc
//Set information about the monit server address, port and login details.
$addr = 'localhost';
$port = 2812;
$path = '/';
$user = 'admin';
$pass = 'monit';
$timeout = 30;
//End of configuration

$urlHandle = fsockopen($addr, $port, $errno, $errstr, $timeout);
socket_set_timeout($urlHandle, $timeout);
$urlString = "GET $path HTTP/1.0\r\nHost: $addr\r\nConnection: Keep-Alive\r\nUser-Agent: MonitPHP\r\n";
$urlString .= "Authorization: Basic ".base64_encode("$user:$pass")."\r\n";
$urlString .= "\r\n";
fputs($urlHandle, $urlString);
$response = fgets($urlHandle);
$endHeader = false;                           // Strip initial header information

while ( !$endHeader){
  if (fgets($urlHandle) == "\r\n")
    $endHeader = true;
}
 $info = ;                                  // Generate a string to send to the screen

while (!feof($urlHandle)) {
  $info.=fgets($urlHandle);
}
 fclose ($urlHandle);
echo $info;
?>

Créer /etc/apache2/conf.d/monit.conf :

<IfModule mod_alias.c>
  Alias /monit "/var/www/monit"
</IfModule>

<DirectoryMatch /var/www/monit/>
  Options -FollowSymLinks
  AllowOverride All
  order deny,allow
#  deny from all
#  allow from 127.0.0.0/255.0.0.0
</DirectoryMatch>

Créer /var/www/.htaccess :

AuthUserFile /var/www/monit/.htpasswd
 AuthName "Restricted Access"
 Require valid-user
 AuthType Basic

<Files .*>
deny from all
</Files>

Et créer le fichier de mots de passe avec user admin/<mot de passe admin> :

# htpasswd -c /var/www/monit/.htpasswd admin