{{tag>[centos nagios monitoring]}}
=====Nagios 4 - CentOS 6.4=====
Nagios 4 is not available via repo (yet) so we install from source.

====Install requisites====
  yum install -y wget httpd php gcc glibc glibc-common gd gd-devel make net-snmp openssl-devel net-snmp-utils
====Compile Nagios from source====
Download source from [[http://www.nagios.org|Nagios]]

Extract source code:
  tar zxvf nagios-4.0.1.tar.gz

Create user and group:
  useradd nagios
  groupadd nagcmd
  usermod -a -G nagcmd nagios

Extract source code:
  tar zxvf nagios-4.0.1.tar.gz
  tar zxvf nagios-plugins-1.5.tar.gz
  
Configure:
  cd nagios-4.0.1
  ./configure --with-command-group=nagcmd

Compile and install:
  make all
  make install
  make install-init
  make install-config
  make install-commandmode
  make install-webconf
  make install-exfoliation

====Post configuration====
  cp -R contrib/eventhandlers/ /usr/local/nagios/libexec/
  chown -R nagios:nagios /usr/local/nagios/libexec/eventhandlers
  /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

  chown nagios.nagiocmd /usr/local/nagios/var/rw
  chown nagios.nagcmd /usr/local/nagios/var/rw
  chmod u+rwx /usr/local/nagios/var/rw
  chmod g+rwx /usr/local/nagios/var/rw
  chmod g+s /usr/local/nagios/var/rw


  /etc/init.d/nagios start
  /etc/init.d/httpd start
====Create web user====
  htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
  
====Install plugins====
  cd nagios-plugins-1.5
  ./configure --with-nagios-user=nagios --with-nagios-group=nagios
  make
  make install


====Start Nagios at boot====
  chkconfig --add nagios
  chkconfig --level 35 nagios on
  chkconfig --add httpd
  chkconfig --level 35 httpd on

====Open firewall====
Edit /etc/sysconfig/iptables
<code>-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT</code>

Restart iptables:
  service iptables restart
  
====SELinux====
  chcon -R -t httpd_sys_content_t /usr/local/nagios/sbin/
  chcon -R -t httpd_sys_content_t /usr/local/nagios/share/
  chcon -R -t httpd_sys_script_rw_t /usr/local/nagios/var/rw

====HTTP index page====
Give the Nagios localhost http check something
  touch /var/www/html/index.html
====Test====
Nagios should be running on your webserver /nagios