How to Install Nagios Server on CentOS/RHEL 8/7/6

    RahulBy 3 Mins ReadUpdated:

    Nagios is the most popular, open source, powerful monitoring system. It enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes. Nagios has the capability of monitoring application, services, entire IT infrastructure.

    Install Nagios Core

    This is Part-1 of complete article How to Setup Nagios Monitoring Server with NagiosQL on CentOS/RHEL 7/6, In this part, you will find the steps to setup Nagios Monitoring Server on CentOS, Redhat, and Fedora systems.

    Step 1 – Install Required Packages

    We assume that you have fresh installed CentOS, Red Hat or Fedora systems, So our first requirement is to install Apache and PHP first. Use the following commands to complete it. You can find detailed LAMP setup instruction here.

    Install Packages:

    yum install httpd php php-cli gcc unzip wget glibc glibc-common gd gd-devel net-snmp
yum groupinstall "development tools"

    Start Apache:

    service httpd start

    Step 2 – Setup User Accounts

    Now create a new nagios user account and setup a password to this account

    useradd nagios
passwd nagios

    Now create a groud for nagios setup “nagcmd” and add nagios user to this group. Also add nagios user in apache group.

    groupadd nagcmd
usermod -a -G nagcmd nagios
usermod -a -G nagcmd apache

    Step 3 – Install Nagios Core Service

    After installing the required dependencies and adding user accounts. Let’s start with the Nagios core installation. Download the latest Nagios core service from the official site.

    cd /opt/
wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.4.5.tar.gz
tar xzf nagios-4.4.5.tar.gz
cd nagios-4.4.5
./configure --with-command-group=nagcmd
make all
make install
make install-init
make install-daemoninit
make install-config
make install-commandmode
 make install-exfoliation

    Now use below command to setup Apache configuration for Nagios installation.

    make install-webconf

    Step 4 – Configure Apache Authentication

    We need to setup apache authentication for user nagiosadmin. Do not change this username. else you would required more changes in configuration.

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

    Now restart Apache service to make the new settings take effect.

    service httpd restart

    Step 5 – Install Nagios Plugins

    After installing and configuring Nagios core service, Download latest nagios-plugins source and install using the following commands.

    cd /opt
wget http://nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz
tar xzf nagios-plugins-2.2.1.tar.gz
cd nagios-plugins-2.2.1

    Now compile and install nagios plugins

    ./configure --with-nagios-user=nagios --with-nagios-group=nagios
make
make install

    Step 6 – Verify and Start Nagios

    First, verify the Nagios configuration file using the following command.

    /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

    If there is no error, let’s start the Nagios serivce

    service nagios start

    Step 7 – Access Nagios in Web Browser

    Nagios creates its own apache configuration file /etc/httpd/conf.d/nagios.conf. There are no need to make any changes to it. Simply open below url in browser.
    [change domain name with your domain or ip]

     http://tecadmin.example.net/nagios/

    Prompting for Apache Authentication Password –

    Nagios After login screen –

    Finally, you have successfully installed and configured Nagios core service in your system. Now go to article install NagiosQL3 web interface for managing Nagios.

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    53 Comments

    2. Stephony on

      Great information shared. Adding a few lines about Nagios, ” Nagios provides complete monitoring of Linux operating systems and distributions – including operating system metrics, service state, process state, file system usage, and more.”

      Reply
    4. Noman on

      Your first step successfully done[How to Install Nagios 4 (Monitoring Server) on CentOS/RHEL 7/6] & its very helpful to understand. Would u plz tell me process, how to add host? & what another services are need to installed ? Plz Note I am using centos7 .

      Reagards

      Reply
      • David on

        This is just a simple guide, but check some examples.

        –Open this file
        nano /usr/local/nagios/etc/nagios.cfg

        —search and uncoment
        #cfg_file=/usr/local/nagios/etc/objects/switch.cfg

        —to

        cfg_file=/usr/local/nagios/etc/objects/switch.cfg

        —close file

        —Open and add these command below (host and 2 services to monitoring)
        nano /usr/local/nagios/etc/objects/switch.cfg

        define host{
        use generic-switch
        host_name switchcore01
        alias swtich main num 1
        address 10.10.10.3
        hostgroups switches
        }

        define service{
        use generic-service
        host_name switchcore01
        service_description PING
        check_command check_ping!200.0,20%!600.0,60%
        normal_check_interval 5
        retry_check_interval 1
        }

        define service {
        use generic-service
        host_name switchcore01
        service_description Uptime
        check_command check_snmp!-C MYCOMMUNITYHERE -o sysUpTime.0
        }

        —-close the file

        —–checck the config
        sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

        — now reload the service

        sudo service nagios reload

        —-You can see on the web browser.

        Regards

        Reply
    7. Nirbhay on

      Hi I followed all lines.
      While i was writing command make make all
      got error “make: *** No rule to make target `all’. Stop.”
      make utility allready installed.
      Please help in this.

      Reply
    8. serge on

      hi i am serge
      i have install nagios properly when i run nagios.service i have this message “job for nagios.service failed because the control process exited with error code” thanks for your help

      Reply
    10. srinivas on

      Hi Team,

      I installed Nagios on Linux, with all the steps as mentioned above. but while logging I am not able to login. getting error like
      ” Authorization Required

      This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn’t understand how to supply the credentials required.

      Apache/2.2.15 (Red Hat) Server at 172.29.218.194 Port 80″

      Can some one help on this please.

      Reply
    11. bilal malik on

      i have gone through all the commands its open login page where i put the user nagioadmin and password i gave at the time of creation on user, but the user is not authenticated, please tell me whats error. i have changed the password of this user as well but go not log in.

      please tell

      Reply
      • Raja on

        Hey Bilal,
        Not sure if you have the correct user name. It is nagiosadmin and not nagioadmin . I was able to get it working without any issues

        Reply
    12. Srikanth Reddy on

      Very good notes

      and i have one question

      if you create a two user u1 and u2
      and first log in to u1 and without logout
      try to log in to u2 it is asking some password
      by defualt what password it is tacking can you please solve this query….

      Reply
    13. warren on

      Complete steps! – installed on CentOS 6 x64 after much trying and reading…

      Nagios Centos Install

      # rpm -Uvh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
      # rpm -Uvh http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
      yum –enablerepo=remi install httpd
      service httpd start
      chkconfig httpd on
      sudo rpm -Uvh http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm
      yum install mysql mysql-server
      service mysqld start
      yum install php php-mysql
      yum install php-common php-cli php-mysql php-devel
      service httpd restart
      service mysqld restart
      yum install httpd php php-cli gcc glibc glibc-common gd gd-devel net-snmp
      service httpd start
      useradd nagios
      passwd nagios

      ​ Step 2: Setup User Accounts
      Now create a new nagios user account and setup a password to this account
      # useradd nagios
      # passwd nagios
      Now create a groud for nagios setup “nagcmd” and add nagios user to this group. Also add nagios user in apache group.
      # groupadd nagcmd
      # usermod -a -G nagcmd nagios
      # usermod -a -G nagcmd apache
      ​ Step 3: Install Nagios Core Service
      After installing required dependencies and adding user accounts. Lets start with Nagios core installation. Download latest nagios core service from official site.
      # cd /opt/
      # wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-4.0.8.tar.gz
      # tar xzf nagios-4.0.8.tar.gz
      # cd nagios-4.0.8
      # ./configure –with-command-group=nagcmd
      # make all
      # make install
      # make install-init
      # make install-config
      # make install-commandmode
      Now use below command to setup apache configuration for Nagios installation.
      # make install-webconf
      ​ Step 4: Configure Apache Authentication
      We need to setup apache authentication for user nagiosadmin. Do not change this username. else you would required more changes in configuration.
      # htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
      Now restart Apache service to make the new settings take effect.
      # service httpd restart
      ​ Step 5: Install Nagios Plugins
      After installing and configuring Nagios core service, Download latest nagios-plugins source and install using following commands.
      # cd /opt
      # wget http://nagios-plugins.org/download/nagios-plugins-2.0.3.tar.gz
      # tar xzf nagios-plugins-2.0.3.tar.gz
      # cd nagios-plugins-2.0.3
      Now compile and install nagios plugins
      # ./configure –with-nagios-user=nagios –with-nagios-group=nagios
      # make
      # make install
      ​ Step 6: Verify and Start Nagios
      Use the following commands to verify nagios install and start nagios core service.
      # /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
      # service nagios start
      Also configure nagios service to start on system start
      # chkconfig –add nagios
      # chkconfig nagios on
      firewall-cmd –add-port=80/tcp –permanent

      # vim /etc/sysconfig/selinux
      SELINUX=disabled

      REBOOT SERVER.

      Service mysqld start
      service https start
      service nagios start

      Logon on to nagios from web brower!

      Reply
    14. Hosney Osman on

      it’s not comment
      thank you so much for your effort writing this article
      i want to say unzip is a mandatory package for installation

      Reply
    15. Constantin on

      Hello Rahul,
      i have a question,
      why we have to install apache and not nginx? (I am not asking the differences between them) but it has to do with the nagios program? e.g isn’t compatible or something like that?

      Reply
      • Mandar on

        With Nagios, you can monitor your entire infrastructure (critical servers and network components) with ease, on a web interface. In case anything goes wrong, you receive a notification and the issue gets addressed in timely manner.

        And best thing is that, Nagios Core is Free and Open Source, so you can customize it as per your needs.

        Thanks.

        Reply
    18. Seokwon on

      Hi
      I finish all progress . but I can’t see local host status
      Current, My nagios web page show the message ‘unable to get process status’
      Do you know this problem?

      Reply
    19. Sanjay on

      I am getting this error when i am trying to open via browser

      Forbidden

      You don’t have permission to access /nagios on this server.

      Reply
    20. Steve on

      Hi,

      We are trying to install this, and all went well – but on the homepage we get an error saying “Unable to get process status” and no other page will load – internal server error.

      Steve

      Reply
      • Jonathan on

        I had this problem as well. Try the selinux suggestion above. When things don’t work and you did everything right with no errors, for me 9 times out of 10 the problem is selinux. I try to remember to try this first now.

        Reply
    21. Ajit on

      Hello,
      I have followed these steps and it is successfully installed on my VM (CentOS) and everything was fine but next day when I again poweered on my VM and tried to take web access it gives me an error I have checked nagios service and process as well but no use I’m not able to get my web access
      any one can help…

      Reply
    22. muhammad farooq on

      “” FACING PROBLEM WITH FOLLOWING ERROR”
      make[1]: Leaving directory `/opt/nagios-plugins-2.0.3/po’
      make[1]: Entering directory `/opt/nagios-plugins-2.0.3′
      make[2]: Entering directory `/opt/nagios-plugins-2.0.3′
      make[2]: Nothing to be done for `install-exec-am’.
      make[2]: Nothing to be done for `install-data-am’.
      make[2]: Leaving directory `/opt/nagios-plugins-2.0.3′
      make[1]: Leaving directory `/opt/nagios-plugins-2.0.3′
      [[email protected] nagios-plugins-2.0.3]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
      bash: /usr/local/nagios/bin/nagios: No such file or directory
      <

      Reply
    25. Ronald on

      It works GREAT and thanks however, when i reboot the server nagios does not start back up.

      I have doen theis on CentOS 6.5 then 7 same results.

      Please help.

      Reply
    26. Naresh Bhanushali on

      Hi Rahul,

      Recently, I just deleted my /etc/passwd and /etc/group file in my nagios server. Luckily, I restored it from the backup I had. But after that, I am not able to import data to remote nagios server over SSH/SFTP using nagiosql.
      I can login directly without password from local system to remote system, but getting error for permission check. I have also tried to change ownership to apache user and nagios user vice-versa. But no use. Do you have exact idea where should I be wrong going as unluckily, I had restarted the corrupted slave simnagios and due to that getting stale results.

      Reply
        • Hubalda on

          Thanks for reply, but terminal was wrote: directory or file does not exist. In directory html/webadmin is created directory config.

          Reply
          • Rahul on

            Hi Hubalda,
            If you are talking about warning “setting file doesn’t exists”, Then no worry, Just continue to next if other issues are fixed. setting.php will automatically created by installer using input given.

            Reply
    29. Jon on

      I’ve gone through all your steps several times and it still doesn’t work. I can navigate to the site “Settings file not found or not readable (config/settings.php). Upgrade not available!” When i click the Start installation it says “SSH2: Not Available”, “MySQL: Not Available”, “date.timezon: Not Available (cannot be empty and needs to be set)”, “Write test on settings directory (config/): failed”

      Now i’ve installed all of these programs and started/added to services. I’ve edited the php.ini file to have America/Denver as my timezone. I’ve disable the iptables to make sure somethings not being blocked.

      Do you have any input on how i can solve this. Any assistance would be much appreciated.

      Reply
      • Rahul on

        Hi Jon,

        1. make sure you have assigned privileges to apache user on config directory
        2. To install SSH2 use below commands.
        # yum install libssh2-devel libssh2

        # pecl install ssh2
        or
        # pecl install channel://pecl.php.net/ssh2-0.12

        3. For MysQL
        # yum install php-mysql

        I hope above steps will fix your issues.

        Reply
        • Jon on

          Thank you for your reply. I’m still having issues getting pecl install ssh2 and pecl install channel://pecl.php.net/ssh2-0.12 installed. it gives me an error. ERROR: ‘phpize’ failed. If you have input it would be much appreciated.

          Thanks,

          Jon

          Reply
            • Jon on

              So I’ve actually resolved the ssh2 issue now. But I’m now unable to get mysql to work. It says “MySQL: Not Available”.
              Now I’m quite sure i’ve installed everything properly. This only thing i’m questionable on is php-mysql. I’ve tried the yum install php-mysql with no success. It returns:

              Loaded plugins: fastestmirror, security
              Loading mirror speeds from cached hostfile
              * base: mirrors.usinternet.com
              * epel: linux.mirrors.es.net
              * extras: mirrors.xmission.com
              * updates: mirrors.easynews.com
              Setting up Install Process
              Resolving Dependencies
              –> Running transaction check
              —> Package php-mysql.x86_64 0:5.3.27-1.el6 will be installed
              –> Processing Dependency: php-pdo(x86-64) = 5.3.27-1.el6 for package: php-mysql-5.3.27-1.el6.x86_64
              –> Running transaction check
              —> Package php-pdo.x86_64 0:5.3.27-1.el6 will be installed
              –> Processing Dependency: php-common(x86-64) = 5.3.27-1.el6 for package: php-pdo-5.3.27-1.el6.x86_64
              –> Finished Dependency Resolution
              Error: Package: php-pdo-5.3.27-1.el6.x86_64 (CentALT)
              Requires: php-common(x86-64) = 5.3.27-1.el6
              Installed: php-common-5.4.19-1.el6.remi.x86_64 (@remi)
              php-common(x86-64) = 5.4.19-1.el6.remi
              Available: php-common-5.3.3-22.el6.x86_64 (base)
              php-common(x86-64) = 5.3.3-22.el6
              Available: php-common-5.3.3-23.el6_4.x86_64 (updates)
              php-common(x86-64) = 5.3.3-23.el6_4
              Available: php-common-5.3.27-1.el6.x86_64 (CentALT)
              php-common(x86-64) = 5.3.27-1.el6
              You could try using –skip-broken to work around the problem
              You could try running: rpm -Va –nofiles –nodigest

              So I’m not sure if its a installation problem or if i need to configure a file or something.

              Thanks,

              Jon Nelson

              Reply
        • Jon on

          So I see that when I install MySQL it installs mariadb instead. Do you think this would be causing a linking error? Do you know why mariadb is installing instead of MySQL? I’m confused as to why this is being so much trouble.

          Thanks again!

          Jon

          Reply

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