This tutorial will show you how to install Nagios3 on a Debian Lenny Server a.k.a Nagios on Debian Lenny Walkthrough
Prerequisites:
* a physical or virtual server
* The first Debian Installation cd – http://www.debian.org/CD/http-ftp/#stable
* Basic Linux & Nagios Knowledge
* One to two hours of time
* Copy & Paste Skills 🙂
====== Debian Lenny Installation ======
* Get the first cd Image from [[http://www.debian.org]]
* Boot the cd
* Choose “Install”
* Choose your Language (english)
* Choose Country
* Choose Keymap
* Choose Hostname
* Choose Domain Name
* Choose “use entire Disk” (if you are not familiar with linux partitioning) (you need ~ 8 GB of space)
* The last Nagios Server that i have installed look like this
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 327M 129M 182M 42% /
tmpfs 494M 0 494M 0% /lib/init/rw
udev 10M 96K 10M 1% /dev
tmpfs 494M 0 494M 0% /dev/shm
/dev/sda6 2.1G 1.5G 539M 74% /home
/dev/sda8 373M 13M 341M 4% /tmp
/dev/sda5 4.2G 645M 3.4G 16% /usr
/dev/sda9 4.2G 510M 3.5G 13% /var
* Choose Root Password
* Choose Full Name and Username for new user
* Scan another cd / no
* Use a network mirror / no
* Software selection: choose “Webserver and Standard System”
* Install Grup to the master boot record “yes”
* After the installation is finished reboot and login with root credentials
===== Proxy Authentication =====
If you are behind a firewall with Active Directory Proxy Authentication you have to make sure that the Nagios Server knows the credentials for the proxy server.
Create the following file ///etc/apt/apt.conf//
Acquire::http::Proxy “http://windowsdomainname\username:password@proxy-servername:proxyport/”;
===== Debian repositories – Sources.list =====
replace your existing /etc/apt/sources.list with this one
You can replace //ftp.de// with your home country (like //ftp.hu// for hungary , //ftp.pl// for poland etc.
# deb cdrom:[Debian GNU/Linux 5.0.1 _Lenny_ – Official i386 CD Binary-1 20090413-00:10]/ lenny main
deb http://ftp.de.debian.org/debian/ lenny main
deb-src http://ftp.de.debian.org/debian/ lenny main
deb http://ftp.de.debian.org/debian/ lenny main contrib non-free
deb http://security.debian.org/ lenny/updates main
deb-src http://security.debian.org/ lenny/updates main
Afterwards Update System with
apt-get update
apt-get upgrade
It is possible that you get a error message after the first apt-get update stating that you have duplicate entries. Simply type in a//pt-get update// and it will work.
===== Optional – VMWare Tools =====
In case you are using your linux server on a virtual machine running on VMWare ESX you can / should install the vmware tools.
Make sure you are Logged on to the console (don’t use a ssh session – as it will not work)
apt-get install open-vm-tools
see: http://wiki.debian.org/VMware for details
===== SSH Access, Additional tools & additional packages =====
apt-get install openssh-server
apt-get install build-essential mc vim ntpdate smbfs
apt-get install nagios3
apt-get install libsnmp-perl libsnmp-session-perl
Hey you finally installed Nagios 😉
===== Nagios @ Debian Bugfixes =====
chmod -R g+s /etc/nagios3
dpkg-statoverride –update –add nagios www-data 2710 /var/lib/nagios3/rw
dpkg-statoverride –update –add nagios nagios 751 /var/lib/nagios3
===== Nagios Configuration =====
the the following in ///etc/nagios3/nagios.cfg//
# change 0 to 1
check_external_commands=1
Reload nagios afterwards with
/etc/init.d/nagios3 restart
===== Configure NTP =====
vim /etc/cron.hourly/settime.sh
#!/bin/sh
ntpdate -t 60 NTPServer; hwclock -u –systohc
set permissions with
chmod +x /etc/cron.hourly/settime.sh
===== Install Postfix =====
apt-get install postfix
===== Install Nagiosgrapher =====
apt-get install nagiosgrapher
To tell nagios to write service perfdata change line 1 and add line 2 in /etc/nagios3/nagios.cfg
# change from 0 to 1
process_performance_data=1
# add this line
service_perfdata_command=ngraph-process-service-perfdata-pipe
===== Nagios SNMP Plugins =====
Get additional plugins to monitor:
disks, memory, swap, everthing in hrStorage table, interface state and usage, check memory and cpu usage of processes, the number (can be 1) of processes matching a perl regexp, cpu or average load etc.
from here http://nagios.manubulon.com/snmp_storage.html
Copy the plugins to the Nagios Plugin Directory and change the path within the scripts as shown below
# Nagios specific
use lib “/usr/lib/nagios/plugins”;
===== Configure Access to the Nagios Webpage =====
htpasswd -c /etc/nagios3/htpasswd.users nagiosadmin
Try to connect to Nagios with the following url: http://your-nagios-server/nagios3
===== SNMP configuration for Windows Servers =====
We will use SNMP to monitor most of the services so make sure that SNMP is configured on the servers that you would like to monitor.
A documentation about how to Install and Enable SNMP Service in Windows XP, Vista and 2003 can be found here
====== Adding Hosts & Hostgroups and Services ======
===== Commands.cfg Definition =====
Add the following to your /etc/nagios3/commands.cfg file
define command {
command_name check_snmp_storage
command_line $USER1$/check_snmp_storage.pl -H $HOSTADDRESS$ -C $ARG1$ -m $ARG2$ -w 95 -c 97 -f
# comment Community, storage, warn, crit, arguments
}
define command {
command_name check_snmp_memory
command_line $USER1$/check_snmp_storage.pl -H $HOSTADDRESS$ -C $ARG1$ -m Memory -w $ARG2$ -c $ARG3$ -f
# comment Community, storage, warn, crit, arguments
}
define command {
command_name check_snmp_load
command_line $USER1$/check_snmp_load.pl -H $HOSTADDRESS$ -C $ARG1$ -w $ARG2$ -c $ARG3$
# comment Comunity, process
}
define command {
command_name check_snmp_process
command_line $USER1$/check_snmp_process.pl -H $HOSTADDRESS$ -C $ARG1$ -n $ARG2$
# comment Comunity, process
}
# Microsoft SQL Server
# check_mssql command definition
define command{
command_name check_mssql
command_line /usr/lib/nagios/plugins/check_mssql.sh $HOSTNAME$ $ARG1$ $ARG2$ $ARG3$
}
Create a new Service Template <sitename>.cfg in the /etc/nagios3/conf.d directory
Hint: Rename hostgroups_nagios2.cfg to <sitename>.cfg this will make is easier to have everything in one file.
# Service Templates
define service {
name template1 ; 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
register 0 ; DONT REGISTER THIS DEFINITION – ITS NOT A REAL SERVICE, JUST A TEMPLATE!
#service_description Check Disk Space
is_volatile 0
check_period 24×7
max_check_attempts 2
normal_check_interval 5
retry_check_interval 1
contact_groups admins
notification_options w,c,u
notification_interval 960
notification_period 24×7
}
===== Define Hosts =====
# hosts
define host{
use generic-host
host_name clusternode1
alias Cluster Node 1
address 15.111.41.14
check_command check-host-alive
}
define host{
use generic-host
host_name clusternode2
alias Cluster Node 2
address 15.111.41.15
check_command check-host-alive
}
===== Create Hostgroups =====
Based on this Hostgroups we choose which services are being monitored
# nagios doesn’t like monitoring hosts without services, so this is a group for devices that have no other “services” monitorable(like routers w/out snmp for example)
define hostgroup {
hostgroup_name ping-servers
alias Pingable servers
members gateway,router, clusternode1, clusternode2
}
define hostgroup {
hostgroup_name windows-servers
alias Windows Servers
members clusternode1, clusternode2
}
===== Service Definitions =====
==== Check Disk Space ====
# Check Disk Space Drive C
define service{
use template1
hostgroup_name windows-servers
check_command check_snmp_storage!snmp-community-name!”^C:”
service_description Check Disk Space C:
}
# Check Disk Space Drive F
define service{
use template1
host_name SRV0002554
check_command check_snmp_storage!snmp-community-name!”^F:”
service_description Check Disk Space F:
}
==== Memory usage ====
define service{
use template1
hostgroup_name windows-servers
check_command check_snmp_memory!snmp-community-name!95!97
service_description Memory usage
}
==== CPU usage ====
define service{
use template1
hostgroup_name windows-servers
check_command check_snmp_load!snmp-community-name!90%!95%
service_description CPU usage
}
==== RDP Port ====
define service{
name rdp_connect
service_description Remote Desktop Connection
use template1
hostgroup_name windows-servers
check_command check_tcp!3389
}
==== Citrix ICA ====
define service{
name citrix_ica_listener
service_description Citrix ICA
use template1
hostgroup_name Terminalserver
check_command check_tcp!1494
}
==== MS-SQL Servers ====
Nagios should try to logon to the SQL Servers. We need some libaries from the freetds project to make this work.
=== Freetds Installation to monitor MS-SQL ===
Download the freetds Client from the project homepage at http://www.freetds.org/
tar -xzf freetds-stable.tgz
cd freetds-0.82
#if not already installed
apt-get install build-essential
export SYBASE=/usr/local/bin
./configure
make
make install
Create the following file
vim /etc/freetds.conf
and list your SQL Servers here
Use the Hostname from the hosts defintion within the brackets.
Make sure that you use the correct TCP/IP Port (see this Microsoft Article for details
; Microsoft SQL Protokoll Version. SQL7 = 7.0, SQL2000 = 8.0
;tds version = 8.0
[sqlserver1]
host = 11.111.41.27
port = 1433
tds version = 8.0
[sqlserver2]
host = 11.111.41.28
port = 1469
tds version = 8.0
define service{
name check_mssql
service_description Check logon to SQL Servers
use template1
hostgroup_name database-servers
check_command check_mssql!SQLServerUsername!Password!2000
}
===== VMWare Virtual Center =====
Important Services on a VMWare Virtual Center
define service {
use template1
name check_process_vpxd.exe
service_description VMWare VirtualCenter Service
host_name ESX01
check_command check_snmp_process!SNMP-COMMUNITY-NAME!vpxd.exe
}
define service {
use template1
name check_process_tomcat5.exe
service_description VMWare Infrastructure Web Access
host_name ESX01
check_command check_snmp_process!SNMP-COMMUNITY-NAME!tomcat5.exe
}
define service {
use template1
name check_process_lmgrd.exe
service_description VMWare Licence Server
host_name ESX01
check_command check_snmp_process!SNMP-COMMUNITY-NAME!lmgrd.exe
}
define service {
use template1
name check_process_sqlservr.exe
service_description MS SQL Service
host_name ESX01
check_command check_snmp_process!SNMP-COMMUNITY-NAME!sqlservr.exe
}
====== Nagios configuration check ======
As i am lazy i always create two files in /usr/local/bin
Filename: nagcheck.sh
#!/bin/sh
# Check nagios config
/usr/sbin/nagios3 -v /etc/nagios3/nagios.cfg
Filename: nagrestart.sh
#!/bin/sh
# Check nagios config
/etc/init.d/nagios3 restart
Don’t forget to make the files executable with
chmod +x /usr/local/bin/nagcheck.sh
chmod +x /usr/local/bin/nagrestart.sh
====== Backups ======
Finally – if everything works as expected you should configure a daily backup.
Perform a backup each day at 5:00
vim /etc/cron.d/backup
5 0 * * * root /usr/local/bin/backup.sh
vim /usr/local/bin/backup.sh
#!/bin/sh
# Backup Script – Create Tar Files on BACKUPSERVERNAME (Backup Server)
# don’t forget to create the mountmount /mnt/BACKUPSERVERNAME/
mount -t smbfs -o username=BACKUPSERVERNAME\\WINDOWSUSERNAME,password=WINDOWSPASSWORD,lfs //FULLQUALIFIED-DNSNAME/SHARENAME /mnt/BACKUPSERVERNAME
rm /mnt/BACKUPSERVERNAME/NAGIOSSERVERNAME/NAGIOSSERVERNAME-etc.tar.gz
rm /mnt/BACKUPSERVERNAME/NAGIOSSERVERNAME/NAGIOSSERVERNAME-plugins.tar.gz
rm /mnt/BACKUPSERVERNAME/NAGIOSSERVERNAME/nagios-full.tar.gz
tar -czf /mnt/BACKUPSERVERNAME/NAGIOSSERVERNAME/NAGIOSSERVERNAME-etc.tar.gz /etc/*
tar -czf /mnt/BACKUPSERVERNAME/NAGIOSSERVERNAME/NAGIOSSERVERNAME-plugins.tar.gz /usr/lib/nagios/plugins/*
tar -czf /mnt/BACKUPSERVERNAME/NAGIOSSERVERNAME/nagios-full.tar.gz /* –exclude=/proc –exclude=/sys –exclude=/dev –exclude=/media –exclude=/mnt/BACKUPSERVERNAME
umount /mnt/BACKUPSERVERNAME
Make the script executable
vim /usr/local/bin/backup.sh
That’s it.
Happy Monitoring !
2oznet 