[nagios - install on centos 7] #nagios

nagios-on-centos7.md

Nagios on CentOS 7

Install Nagios Core

1. Install package

$ yum install wget httpd php glibc glibc-common gd gd-devel 
make net-snmp unzip openssl-devel gcc

2. Add user

$ useradd nagios -p nagios
$ usermod -a -G nagios apache

3. Install

$ wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.2.4.tar.gz
$ tar zxvf nagios-4.2.4.tar.gz
$ cd nagios-4.2.4
$ ./configure
$ make all
$ make install
$ make install-init
$ make install-config
$ make install-commandmode
$ make install-webconf

Install Nagios Plugin

1. Install package

$ yum install epel-release
$ yum install perl-Net-SNMP

$ yum install openssl-devel radiusclient-ng-devel libdbi libdbi-devel 
samba-devel libsmbclient-devel samba-client net-snmp-devel net-snmp-utils 
gnutls-devel openldap-devel postgresql-devel

2. Install

$ wget https://nagios-plugins.org/download/nagios-plugins-2.1.4.tar.gz
$ tar zxvf nagios-plugins-2.1.4.tar.gz
$ cd nagios-plugins-2.1.4.tar.gz
$ ./configure
$ make
$ make install

Start Nagios

1. Start service

   $ systemctl start nagios
   $ systemctl enable nagios

2. Set firewall (TCP 80 port)

   $ firewall-cmd --add-service=http
   $ firewall-cmd --add-service=https
   $ firewall-cmd --reload

3. Set password for Web administrator Default admin: nagiosadmin

   $ htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

4. Start httpd

   $ systemctl start httpd

5. Login to Web http://<ip>/nagios
6. Set system time

   $ yum install chrony

   Add NTP server: server watch.stdtime.gov.tw

   $ vim /etc/chrony.conf
   

   $ timedatectl set-timezone "Asia/Taipei" 
   $ timedatectl set-ntp yes
   

Install NRPE(Nagios Remote Plugin Executor)

Remote Host

1. Install package

   yum install openssl-devel gcc xinetd

2. Update /etc/services

   $vim /etc/services

   add item

   nrpe            5666/tcp                # Nagios addon NRPE
   

3. Intall Nagios Plugin

   $ yum install epel-release
   $ yum install perl-Net-SNMP
   $ yum install openssl-devel radiusclient-ng-devel libdbi 
   libdbi-devel samba-devel libsmbclient-devel net-snmp-devel 
   gnutls-devel openldap-devel postgresql-devel
   
   $ wget https://nagios-plugins.org/download/nagios-plugins-2.1.4.tar.gz
   $ tar zxvf nagios-plugins-2.1.4.tar.gz
   $ cd nagios-plugins-2.1.4/
   $ ./configure
   $ make
   $ make install

4. Install NRPE

   $ wget https://github.com/NagiosEnterprises/nrpe/archive/nrpe-3.0.1.tar.gz
   $ tar zxvf tar zxvf nrpe-3.0.1.tar.gz
   $ cd nrpe-nrpe-3.0.1/
   $ ./configure
   $ make all
   $ make install
   $ make install-config
   $ make install-inetd
   $ make install-init
   $ make install-groups-users

5. Start NRPE and xinetd

   $ systemctl restart xinetd
   $ systemctl enable nrpe
   $ systemctl start nrpe

6. Check service If only tcp6, it's need to disable IPv6 function.

   $ netstat -at | egrep "nrpe|5666"
   tcp        0      0 0.0.0.0:nrpe            0.0.0.0:*               LISTEN
   tcp6       0      0 [::]:nrpe               [::]:*                  LISTEN

7. Check command

   $ /usr/local/nagios/libexec/check_nrpe -H localhost
   NRPE v3.0.1

   $ /usr/local/nagios/libexec/check_nrpe -H localhost -c check_users
   USERS OK - 2 users currently logged in |users=2;5;10;0

8. Update nrpe.cfg

   $ vim /usr/local/nagios/etc/nrpe.cfg

   Add allowed_hosts for nagios server(10.136.160.119)

   allowed_hosts=127.0.0.1
   allowed_hosts=10.136.160.119

Nagios Server

1. Install NRPE

   $ wget https://github.com/NagiosEnterprises/nrpe/archive/nrpe-3.0.1.tar.gz
   $ tar zxvf tar zxvf nrpe-3.0.1.tar.gz
   $ cd nrpe-nrpe-3.0.1/
   $ ./configure
   $ make check_nrpe
   $ make install-plugin

2. Check command for remote host

   $ /usr/local/nagios/libexec/check_nrpe -H 10.136.161.101 -c check_users
   USERS OK - 2 users currently logged in |users=2;5;10;0

Reference

• CentOS 7 安裝NAGIOS 4
• RHEL / CentOS 停用 IPv6