So CentOS 7 is out and there are quite some differences from it’s predecessor CentOS 6. This is why i decided to write a new how to installing Nagios Core 4.0.8 on the latest fully updated CentOS 7 minimal installation – Install Nagios on CentOS 7. The Firewalld and SELinux are both enabled and running in this how to so you should not have any problems with it. If you are not familiar with using Systemd and Firewalld there are couple of commands to get you in the right direction and maybe slowly get used to it – i sure need/want to too.
Let’s Install Nagios on CentOS 7!
1. Install “deltarpm” package
The first step to install nagios on CentOS7 is to install “deltarpm”. This package creates deltas between RPMs. It is required in future RPM installations.
[root@geekpeek ~]# yum install deltarpm -y
2. Install Required Dependencies
These are the packages we need to install to satisfy Nagios dependency resolution, when compiling it.
[root@geekpeek ~]# yum install wget httpd php gcc glibc glibc-common gd gd-devel make net-snmp -y
3. Download the Latest Version of Nagios Core
The latest version of Nagios Core is available for free download at THIS link.
[root@geekpeek ~]# wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-4.0.8.tar.gz
4. Create “nagios” User and add “apache” User to Nagios Group
Before compiling Nagios Core we need to create “nagios” user and group. When “nagios” user and group is created, add “apache” user to this group – this needs to be done due to some file permissions which enable us to do actions via Nagios web interface.
[root@geekpeek ~]# useradd nagios [root@geekpeek ~]# usermod -G nagios apache
5. Extract Nagios Tarball
[root@geekpeek ~]# tar -xvzf nagios-4.0.8.tar.gz
6. Run Configure and Make Nagios
To install Nagios on CentOS 7 we need to configure and make Nagios.
[root@geekpeek ~]# cd nagios-4.0.8
[root@geekpeek nagios-4.0.8]# ./configure
...
...
Creating sample config files in sample-config/ ...
*** Configuration summary for nagios 4.0.8 08-12-2014 ***:
General Options:
-------------------------
Nagios executable: nagios
Nagios user/group: nagios,nagios
Command user/group: nagios,nagios
Event Broker: yes
Install ${prefix}: /usr/local/nagios
Install ${includedir}: /usr/local/nagios/include/nagios
Lock file: ${prefix}/var/nagios.lock
Check result directory: ${prefix}/var/spool/checkresults
Init directory: /etc/rc.d/init.d
Apache conf.d directory: /etc/httpd/conf.d
Mail program: /bin/mail
Host OS: linux-gnu
IOBroker Method: epoll
Web Interface Options:
------------------------
HTML URL: http://localhost/nagios/
CGI URL: http://localhost/nagios/cgi-bin/
Traceroute (used by WAP):
Review the options above for accuracy. If they look okay,
type 'make all' to compile the main program and CGIs.
[root@geekpeek nagios-4.0.8]# make all
[root@geekpeek nagios-4.0.8]# make install
[root@geekpeek nagios-4.0.8]# make install-init
[root@geekpeek nagios-4.0.8]# make install-commandmode
[root@geekpeek nagios-4.0.8]# make install-config
[root@geekpeek nagios-4.0.8]# make install-webconf
[root@geekpeek nagios-4.0.8]# make install-exfoliation7. Run Nagios Configuration Check
You can do this anytime after changing the Nagios configuration to make sure service restart will be OK.
[root@geekpeek nagios-4.0.8]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
Nagios Core 4.0.8 Copyright (c) 2009-present Nagios Core Development Team and Community Contributors Copyright (c) 1999-2009 Ethan Galstad Last Modified: 08-12-2014 License: GPL Website: http://www.nagios.org Reading configuration data... Read main config file okay... Read object config files okay... Running pre-flight check on configuration data... Checking objects... Checked 8 services. Checked 1 hosts. Checked 1 host groups. Checked 0 service groups. Checked 1 contacts. Checked 1 contact groups. Checked 24 commands. Checked 5 time periods. Checked 0 host escalations. Checked 0 service escalations. Checking for circular paths... Checked 1 hosts Checked 0 service dependencies Checked 0 host dependencies Checked 5 timeperiods Checking global event handlers... Checking obsessive compulsive processor commands... Checking misc settings... Total Warnings: 0 Total Errors: 0 Things look okay - No serious problems were detected during the pre-flight check
8. Create Nagios Web Interface User
Beware, we are creating htpasswd.users file with this name on exact location since this location is default in Nagios configuration file – if you change the file name or location you must edit Nagios configiuration also!
[root@geekpeek nagios-4.0.8]# htpasswd -c -B /usr/local/nagios/etc/htpasswd.users nagiosadmin New password: Re-type new password: Adding password for user admin
9. Install EPEL Repository and “nagios-plugins-all”
We need to install EPEL Repository for CentOS 7 to be able to download “nagios-plugins-all” package. These are all Nagios plugins you might ever need to monitor your Nagios clients. After installing “nagios-plugins-all” we must play around with some links, so Nagios can find the and use plugins – just follow the guide.
[root@geekpeek nagios-4.0.8]# rpm -ivh https://ftp.fau.de/epel/beta/7/x86_64/epel-release-7-0.2.noarch.rpm [root@geekpeek nagios-4.0.8]# yum install nagios-plugins-all -y [root@geekpeek nagios-4.0.8]# rm -rf /usr/local/nagios/libexec [root@geekpeek nagios-4.0.8]# ln -s /usr/lib64/nagios/plugins/ /usr/local/nagios/libexec [root@geekpeek nagios-4.0.8]# chown -R nagios:nagios /usr/local/nagios/libexec/
10. Start Apache and Nagios Service
Note that Apache (httpd) service is native and is manipulated by “Systemd” (systemctl) but Nagios is not native and therefore still manipulated by “SysV” (chkconfig). We must start both services and make sure they start at boot.
[root@geekpeek nagios-4.0.8]# systemctl enable httpd [root@geekpeek nagios-4.0.8]# systemctl start httpd [root@geekpeek nagios-4.0.8]# chkconfig nagios on [root@geekpeek nagios-4.0.8]# /etc/init.d/nagios start
11. Disable Blocking of Port 80
We need to add port 80 (TCP) to “firewalld” permanent exceptions so we can access Nagios web interface.
[root@geekpeek nagios-4.0.8]# firewall-cmd --add-port=80/tcp [root@geekpeek nagios-4.0.8]# firewall-cmd --permanent --add-port=80/tcp
12. Access Nagios Web Interface
This is the last step in install Nagios on CentOS 7 how to. We must confirm that Nagios Web Interface is reachable by accessing http://ip_addr_or_hostname/nagios. Nagios Web Interface should open up.
This is the end of my Install Nagios on CentOS 7 guide. I decided to write a new Nagios Configuration how to so stay tuned!