Pré-requis
Serveur Apache + PHP avec Nagios installé
>>> I. Configuration principale
Nous l’avions vu dans la premeire partie, le configuration de Nagios est rassemblée dans un dossier unique situé sous etc/
Le fichier de configuration principal est etc/nagios.cfg étroitement lié aux CGIs, ces deux fichiers constituent le coeur de la configuration Nagios et liste egalement les autres fichiers de configuration qui seront utilisés:
Voici la liste des principaux fichiers de configuration:
cgi.cfg
commands.cfg
contactgroups.cfg
contacts.cfg
hostgroups.cfg
hosts.cfg
htpasswd.users
nagios.cfg
resource.cfg
servicegroups.cfg
services.cfg
timeperiods.cfg
Le fichier main.cfg reprend les elements pricnipaux
# NAGIOS USER
# This determines the effective user that Nagios should run as.
# You can either supply a username or a UID.
nagios_user=nagios
# NAGIOS GROUP
# This determines the effective group that Nagios should run as.
# You can either supply a group name or a GID.
nagios_group=nagios
ou par exemple:
# EXTERNAL COMMAND FILE
# This is the file that Nagios checks for external command requests.
# It is also where the command CGI will write commands that are submitted
# by users, so it must be writeable by the user that the web server
# is running as (usually ‘nobody’). Permissions should be set at the
# directory level instead of on the file, as the file is deleted every
# time its contents are processed.
command_file=/usr/local/nagios/var/rw/nagios.cmd
De meme le fichier cgi.cfg regroupe les informations essentielles àà l’interface web ainsi que celles liées à la sécurité de l’interface.
# PHYSICAL HTML PATH
# This is the path where the HTML files for Nagios reside. This
# value is used to locate the logo images needed by the statusmap
# and statuswrl CGIs.
physical_html_path=/usr/local/nagios/share
# URL HTML PATH
# This is the path portion of the URL that corresponds to the
# physical location of the Nagios HTML files (as defined above).
# This value is used by the CGIs to locate the online documentation
# and graphics. If you access the Nagios pages with an URL like
# http://www.myhost.com/nagios, this value should be ‘/nagios’
# (without the quotes).
url_html_path=/nagios
# SYSTEM/PROCESS COMMAND ACCESS
# This option is a comma-delimited list of all usernames that
# can issue shutdown and restart commands to Nagios via the
# command CGI (cmd.cgi). Users in this list can also change
# the program mode to active or standby. By default, *no one*
# has access to this unless you choose to not use authorization.
# You may use an asterisk (*) to authorize any user who has
# authenticated to the web server.
authorized_for_system_commands=nagiosadmin
# GLOBAL HOST/SERVICE VIEW ACCESS
# These two options are comma-delimited lists of all usernames that
# can view information for all hosts and services that are being
# monitored. By default, users can only view information
# for hosts or services that they are contacts for (unless you
# you choose to not use authorization). You may use an asterisk (*)
# to authorize any user who has authenticated to the web server.
authorized_for_all_services=nagiosadmin,guest,nagios,guest
authorized_for_all_hosts=nagiosadmin,guest,nagios,guest
# user who has authenticated to the web server.
authorized_for_all_service_commands=nagiosadmin
authorized_for_all_host_commands=nagiosadmin
>>> II. Configuration des serveurs
L’execution du ./configure avant compilation crée les fichiers samples. Ces derniers sont disponibles apres la compilation en executant la commande suivante: make install-config
Je ne vais pas decrire le contenu des fichiers ici, parmi les fichiers samples générés, prenons celui du localhost (ci dessous) Il en resulte une multitude de définition d’objets: periode de temps, nom de serveur, service, groupe de serveur, contact. Chacun des paragraphes ci dessous va definir une entité, qui elle meme appartiendra ou sera liée à une autre entité. Un serveur appartiendra à un groupe de serveur. Un serveur sera lié à un contact ou un groupe de contact qui lui meme contiendra des contacts. La syntaxe est relativement simple, ladocumentation nagios et l’example ci dessous suffiront pour débuter
###############################################################################
# LOCALHOST.CFG – SAMPLE OBJECT CONFIG FILE FOR MONITORING THIS MACHINE
#
# Last Modified: 11-27-2006
#
# NOTE: This config file is intended to servce as an *extremely* simple
# example of how you can create your object configuration file(s).
#
###############################################################################
###############################################################################
###############################################################################
#
# TIME PERIODS
#
###############################################################################
###############################################################################
# This defines a timeperiod where all times are valid for checks,
# notifications, etc. The classic “24×7″ support nightmare. 
define timeperiod{
timeperiod_name 24×7
alias 24 Hours A Day, 7 Days A Week
sunday 00:00-24:00
monday 00:00-24:00
tuesday 00:00-24:00
wednesday 00:00-24:00
thursday 00:00-24:00
friday 00:00-24:00
saturday 00:00-24:00
}
# ‘workhours’ timeperiod definition
define timeperiod{
timeperiod_name workhours
alias “Normal” Working Hours
monday 09:00-17:00
tuesday 09:00-17:00
wednesday 09:00-17:00
thursday 09:00-17:00
friday 09:00-17:00
}
# ‘nonworkhours’ timeperiod definition
define timeperiod{
timeperiod_name nonworkhours
alias Non-Work Hours
sunday 00:00-24:00
monday 00:00-09:00,17:00-24:00
tuesday 00:00-09:00,17:00-24:00
wednesday 00:00-09:00,17:00-24:00
thursday 00:00-09:00,17:00-24:00
friday 00:00-09:00,17:00-24:00
saturday 00:00-24:00
}
# ‘none’ timeperiod definition
define timeperiod{
timeperiod_name none
alias No Time Is A Good Time
}
###############################################################################
###############################################################################
#
# COMMANDS
#
###############################################################################
###############################################################################
# NOTE: Sample command definitions can now be found in the sample commands.cfg
# file
###############################################################################
###############################################################################
#
# CONTACTS
#
###############################################################################
###############################################################################
# In this simple config file, a single contact will receive all alerts.
# This assumes that you have an account (or email alias) called
# “nagios-admin” on the local host.
define contact{
contact_name nagios-admin
alias Nagios Admin
service_notification_period 24×7
host_notification_period 24×7
service_notification_options w,u,c,r
host_notification_options d,r
service_notification_commands notify-by-email
host_notification_commands host-notify-by-email
email nagios-admin@localhost
}
###############################################################################
###############################################################################
#
# CONTACT GROUPS
#
###############################################################################
###############################################################################
# We only have one contact in this simple configuration file, so there is
# no need to create more than one contact group.
define contactgroup{
contactgroup_name admins
alias Nagios Administrators
members nagios-admin
}
###############################################################################
###############################################################################
#
# HOSTS
#
###############################################################################
###############################################################################
# Generic host definition template – This is NOT a real host, just a template!
define host{
name generic-host ; The name of this host template
notifications_enabled 1 ; Host notifications are enabled
event_handler_enabled 1 ; Host event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
failure_prediction_enabled 1 ; Failure prediction is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
notification_period 24×7 ; Send host notifications at any time
register 0 ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL HOST, JUST A TEMPLATE!
}
# Linux host definition template – This is NOT a real host, just a template!
define host{
name linux-server ; The name of this host template
use generic-host ; This template inherits other values from the generic-host template
check_period 24×7 ; By default, Linux hosts are checked round the clock
max_check_attempts 10 ; Check each Linux host 10 times (max)
check_command check-host-alive ; Default command to check Linux hosts
notification_period workhours ; Linux admins hate to be woken up, so we only notify during the day
; Note that the notification_period variable is being overridden from
; the value that is inherited from the generic-host template!
notification_interval 120 ; Resend notification every 2 hours
notification_options d,u,r ; Only send notifications for specific host states
contact_groups admins ; Notifications get sent to the admins by default
register 0 ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL HOST, JUST A TEMPLATE!
}
# Since this is a simple configuration file, we only monitor one host – the
# local host (this machine).
define host{
use linux-server ; Name of host template to use
; This host definition will inherit all variables that are defined
; in (or inherited by) the linux-server host template definition.
host_name localhost
alias localhost
address 127.0.0.1
}
###############################################################################
###############################################################################
#
# HOST GROUPS
#
###############################################################################
###############################################################################
# We only have one host in our simple config file, so there is no need to
# create more than one hostgroup.
define hostgroup{
hostgroup_name test
alias Test Servers
members localhost
}
###############################################################################
###############################################################################
#
# SERVICES
#
###############################################################################
###############################################################################
# Generic service definition template – This is NOT a real service, just a template!
define service{
name generic-service ; The ‘name’ of this service template
active_checks_enabled 1 ; Active service checks are enabled
passive_checks_enabled 1 ; Passive service checks are enabled/accepted
parallelize_check 1 ; Active service checks should be parallelized (disabling this can lead to major performance problems)
obsess_over_service 1 ; We should obsess over this service (if necessary)
check_freshness 0 ; Default is to NOT check service ‘freshness’
notifications_enabled 1 ; Service notifications are enabled
event_handler_enabled 1 ; Service event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
failure_prediction_enabled 1 ; Failure prediction is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
is_volatile 0 ; The service is not volatile
register 0 ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}
# Local service definition template – This is NOT a real service, just a template!
define service{
name local-service ; The name of this service template
use generic-service ; Inherit default values from the generic-service definition
check_period 24×7 ; The service can be checked at any time of the day
max_check_attempts 4 ; Re-check the service up to 4 times in order to determine its final (hard) state
normal_check_interval 5 ; Check the service every 5 minutes under normal conditions
retry_check_interval 1 ; Re-check the service every minute until a hard state can be determined
contact_groups admins ; Notifications get sent out to everyone in the ‘admins’ group
notification_options w,u,c,r ; Send notifications about warning, unknown, critical, and recovery events
notification_interval 60 ; Re-notify about service problems every hour
notification_period 24×7 ; Notifications can be sent out at any time
register 0 ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}
# Define a service to “ping” the local machine
define service{
use local-service ; Name of service template to use
host_name localhost
service_description PING
check_command check_ping!100.0,20%!500.0,60%
}
# Define a service to check the disk space of the root partition
# on the local machine. Warning if < 20% free, critical if
# < 10% free space on partition.
define service{
use local-service ; Name of service template to use
host_name localhost
service_description Root Partition
check_command check_local_disk!20%!10%!/
}
# Define a service to check the number of currently logged in
# users on the local machine. Warning if > 20 users, critical
# if > 50 users.
define service{
use local-service ; Name of service template to use
host_name localhost
service_description Current Users
check_command check_local_users!20!50
}
# Define a service to check the number of currently running procs
# on the local machine. Warning if > 250 processes, critical if
# > 400 users.
define service{
use local-service ; Name of service template to use
host_name localhost
service_description Total Processes
check_command check_local_procs!250!400!RSZDT
}
# Define a service to check the load on the local machine.
define service{
use local-service ; Name of service template to use
host_name localhost
service_description Current Load
check_command check_local_load!5.0,4.0,3.0!10.0,6.0,4.0
}