Installer Monit sur Debian

Ce guide est testé sur:

• Debian 6.0 Squeeze

Prérequis

Ce guide nécessite :

• un serveur HTTP Apache 2 avec le script a2tools disponible dans le guide Installer Apache 2 sur Debian.

Paramètres

Renseignez l'adresse e-mail notifiée en cas de problème:

ALERT_EMAIL="root@localhost"

Renseignez le nom de domaine où sera disponible l'application:

DOMAIN="monit.domain.com"

Renseignez le nom du certificat SSL à utiliser (créé via la procédure Créer un certificat SSL / TLS sur Debian) (optionnel, recommandé):

SSL_KEY_NAME="${DOMAIN}"

Installation

Préparation de l'environnement

Installez les logiciels:

command apt-get install monit apg

Configuration

Configurez le délai entre deux vérifications (ici, 2 minutes):

echo "# Delay in seconds between 2 polls:
set daemon 120" \
  > '/etc/monit/conf.d/000-base-configuration'

Configurez l'adresse email notifiée en cas de problème:

command echo "# Email notified when a service has errors.
set mailserver localhost
set alert ${ALERT_EMAIL}" \
  > '/etc/monit/conf.d/000-alert-email'

Activez la journalisation des messages de monit par syslog:

command echo "# Log monit message to /var/log/syslog
set logfile syslog facility log_daemon" \
  > '/etc/monit/conf.d/000-logging'

Déterminez un mot de passe aléatoire pour l'accès à l'interface Web du logiciel:

ADMIN_PASSWORD="$(command apg -m 16 -x 32 -n 1 -a 1 -M NCLS -E "\'\!$" )"

Configurez l'accès à l'interface Web affichant les statuts du logiciel:

command echo "# Enable HTTP status page.
set httpd port 2812 and
    use address localhost  # only accept connection from localhost
    allow localhost        # allow localhost to connect to the server and
    allow admin:${ADMIN_PASSWORD}" \
  > '/etc/monit/conf.d/000-http-status-page'

Activez le démon:

command sed -i \
    -e 's/^startup=.*/startup=1/' \
  '/etc/default/monit'

Démarrez le démon:

/etc/init.d/monit start

Configurez Apache pour afficher les données du logiciel sur le domaine choisi:

if [ -n "${SSL_KEY_NAME}" -a -e "/etc/ssl/private/${SSL_KEY_NAME}.key" ]; then
  command a2tools --template=reverse-proxy --ssl="${SSL_KEY_NAME}" "${DOMAIN}" "http://localhost:2812/"
  command a2tools --template=redirect "${DOMAIN}" "https://${DOMAIN}/"
else
  command a2tools --template=reverse-proxy "${DOMAIN}" "http://localhost:2812/"
fi

Utilisez ces informations pour vous connecter à l'interface Web de l'outil:

echo "URL: http://${DOMAIN}/
Login: admin
Password: ${ADMIN_PASSWORD}"

Surveillance des services

Système

Configurez la surveillance des ressources du système:

echo "# Check general system resources such as load average, cpu and memory
# usage. Each test specifies a resource, conditions and the action to be
# performed should a test fail.
check system $(command hostname --fqdn)
   group base
   if loadavg (1min) > 4 then alert
   if loadavg (5min) > 2 then alert
   if memory usage > 75% then alert
   if cpu usage (user) > 70% then alert
   if cpu usage (system) > 30% then alert
   if cpu usage (wait) > 20% then alert" \
  > '/etc/monit/conf.d/system'

Redémarrez le démon:

/etc/init.d/monit restart

Espace disque

Créez le fichier de configuration de la surveillance de l'espace disque:

echo '# Free disk space monitoring.

# root (/) file system.
check filesystem rootfs
  with path /
  group system
  if space usage > 85% then alert' \
> '/etc/monit/conf.d/disks'

Ajoutez les partitions montées à la surveillance:

command mount \
  | command grep '^/dev' \
  | command grep -v ' / ' \
  | command grep -v 'swap' \
  | command cut --delimiter=' ' --field=3 \
  | while read FILE; do
    command echo "
# ${FILE} filesystem.
check filesystem $(echo "${FILE}" | command sed -e 's|^/||')
  with path ${FILE}
  group system
  if space usage > 95% then alert" \
      >> '/etc/monit/conf.d/disks'
done

Redémarrez le démon:

/etc/init.d/monit restart

SSH

Configuration la surveillance du serveur SSH:

if [ -e '/etc/init.d/ssh' ]; then
  SSH_PORT=$(command grep '^Port' '/etc/ssh/sshd_config' \
      | command sed -e 's/^Port[\t ]*//g') 
  command echo "# SSH server monitoring
check process sshd with pidfile /var/run/sshd.pid
  group base
  start program \"/etc/init.d/ssh start\"
  stop program \"/etc/init.d/ssh stop\"
  if failed host 127.0.0.1 port ${SSH_PORT} protocol ssh then restart
  if 5 restarts within 5 cycles then timeout" \
    > '/etc/monit/conf.d/ssh'
fi

Redémarrez le démon:

/etc/init.d/monit restart

Apache 2

Configurez la surveillance d'Apache 2:

if [ -e '/etc/init.d/apache2' ]; then
  command echo '# Apache 2 server monitoring
check process apache2 with pidfile /var/run/apache2.pid
  group httpd
  start program = "/etc/init.d/apache2 start" with timeout 60 seconds
  stop program = "/etc/init.d/apache2 stop"
  if 3 restarts within 5 cycles then timeout
  if cpu is greater than 60% for 2 cycles then alert
  if cpu > 80% for 5 cycles then restart
  if children > 250 then restart
  if loadavg(5min) greater than 10 for 8 cycles then stop
  if failed host 127.0.0.1 port 80
      protocol http
    then restart' \
    > '/etc/monit/conf.d/apache2'
fi

Redémarrez le démon:

/etc/init.d/monit restart

MySQL

Configurez la surveillance de MySQL:

if [ -e '/etc/init.d/mysql' ]; then
  command echo '# MySQL server monitoring
check process mysqld with pidfile /var/run/mysqld/mysqld.pid
  group database
  start program = "/etc/init.d/mysql start"
  stop program = "/etc/init.d/mysql stop"
  if failed host 127.0.0.1 port 3306 then restart
  if 5 restarts within 5 cycles then timeout' \
    > '/etc/monit/conf.d/mysql'
fi

Redémarrez le démon:

/etc/init.d/monit restart

Exim 4

Configurez la surveillance d'Exim 4:

if [ -e '/etc/init.d/exim4' ]; then
 command echo '# Exim 4 server monitoring
check process exim4 with pidfile /var/run/exim4/exim.pid
 group mail
 start program = "/etc/init.d/exim4 start"
 stop  program = "/etc/init.d/exim4 stop"
 if failed port 25 protocol smtp then restart
 if 5 restarts within 5 cycles then timeout'
   > '/etc/monit/conf.d/exim4'
fi

Redémarrez le démon:

/etc/init.d/monit restart

vsFTPd

Configurez la surveillance de vsFTPd:

if [ -e '/etc/init.d/vsftpd' ]; then
  command echo '# vsFTPd server monitoring
check process vsftpd with pidfile /var/run/vsftpd/vsftpd.pid
  group ftp
  start program = "/etc/init.d/vsftpd start"
  stop program  = "/etc/init.d/vsftpd stop"
  if failed port 21 protocol ftp then restart
  if 5 restarts within 5 cycles then timeout' \
    > '/etc/monit/conf.d/vsftpd'
fi

Redémarrez le démon:

/etc/init.d/monit restart

rTorrent

Configurez la surveillance de rTorrent (fonctionnelle uniquement avec le port SCGI actif):

if [ -e '/etc/init.d/rtorrent' ]; then
  SCGI_PORT="$(command grep '^scgi_port' '/etc/rtorrent.rc' \
    | command cut --delimiter=: --fields=2)"
  if [ -n "${SCGI_PORT}" ]; then
    command echo "# rTorrent daemon monitoring
check process rtorrent with pidfile /var/run/rtorrent.pid
  group various
  start program = \"/etc/init.d/rtorrent start\" with timeout 60 seconds
  stop program  = \"/etc/init.d/rtorrent stop\"
  if failed port ${SCGI_PORT} then restart
  if 5 restarts within 5 cycles then timeout" \
      > '/etc/monit/conf.d/rtorrent'
  fi
fi

Redémarrez le démon:

/etc/init.d/monit restart

Remerciements

• Merci aux développeurs de Monit.
• Merci à dew de Alsacreation pour Monitoring serveur.