adduser --gecos nagios --disabled-password --disabled-login nagios

On RedHat/CentOS:

adduser nagios

aptitude install nagios-plugins OR aptitude install nagios-plugins-basic nagios-plugins-standard
aptitude install libnagios-plugin-perl (stretch: apt install libmonitoring-plugin-perl)

On RedHat/CentOS:

yum install nagios-plugins

su - nagios
mkdir -m 700 .ssh

Add nagios ssh key:

vi .ssh/authorized_keys
add key...
chmod 600 .ssh/authorized_keys

Connect from icinga server to client before adding checks!

su - nagios
ssh nagios@<IP address>

add this in /etc/apt/apt.conf.d/02periodic:

// Control parameters for cron jobs by /etc/cron.daily/apt //
// Do "apt-get update" automatically every n-days (0=disable)
APT::Periodic::Update-Package-Lists "1";

apt install sysstat

aptitude install libnagios-plugin-perl

On Debian Stretch:

apt install libmonitoring-plugin-perl

CentOS:

yum install perl-Nagios-Plugin

On Stretch change instances of “Nagios::Plugin” to “Monitoring::Plugin” in check_mem.pl script

apt install snmpd

Uncomment in /etc/snmp/snmpd.conf. On wheezy copy check_snmp_int.pl from some other server to /usr/lib/nagios/plugins/

#  Full access from the local host
rocommunity public  localhost
service snmpd restart

On Jessie and Stretch replace

  my $descr_table = '1.3.6.1.2.1.2.2.1.2';

with

  my $descr_table = '1.3.6.1.2.1.31.1.1.1.1';

https://raw.githubusercontent.com/HariSekhon/nagios-plugins/master/check_yum.py

adduser nagios
yum install yum-security
yum install nagios-plugins
su - nagios
mkdir -m 700 .ssh

apt-get install sudo

If error: Remote command execution failed:

start check_raid.pl script, it will create the file:

/home/nagios/bin/check_raid.pl -S

https://github.com/glensc/nagios-plugin-check_raid#supported-raids

then this is not needed:

Remote command execution failed: sudo: no tty present and no askpass program specified

Put this in /etc/sudoers file (use visudo command):

#idev nagios
User_Alias      APTUSER = nagios
Runas_Alias     SUUSER = root
Cmnd_Alias      APTUSERCMD = /home/nagios/bin/check_raid.pl, /home/nagios/bin/apt_wrapper, /home/nagios/bin/checkForDeletedFiles.sh, /home/nagios/bin/check_unix_open_fds.pl, /usr/lib/nagios/plugins/check_ipmi_sensor, /usr/lib/nagios/plugins/check_raid
APTUSER ALL= NOPASSWD: APTUSERCMD

Download check_mongodb.py from https://github.com/mzupan/nagios-plugin-mongodb. Put the script in /home/nagios/bin and install requirements

apt install python-minimal python-pip
pip install pymongo

• New host setup - windows
• Icinga troubleshooting