To monitor Apache2 on an Ubuntu server where Icinga agent is installed, while Icinga server is installed on another Ubuntu server, you can follow these step-by-step instructions. This guide assumes that Icinga 2 and Icinga Web 2 are properly installed and configured on your Icinga server, and the Icinga agent is installed and connected to your Icinga server.

Step 1: Install Necessary Plugins

On the Icinga Agent Server: Ensure you have the nagios-plugins package installed, as it includes the check for Apache. Install it using:

$ sudo apt-get update
$ sudo apt-get install nagios-plugins

Step 2: Configure Icinga Agent

Check the Apache Status Module: Make sure that the Apache status module is enabled on the Apache server. You can enable it with:


$ sudo a2enmod status
$ sudo systemctl restart apache2

Ensure the /etc/apache2/mods-enabled/status.conf is configured to allow access from the Icinga server IP. It might look something like this:


<Location /server-status>
    SetHandler server-status
    Require local
    Require ip 192.168.x.x  # IP of your Icinga server
</Location>

Configure the Agent: On the Icinga agent, ensure it can execute the Apache check. You might need to create a command in Icinga if it doesn’t exist:

object CheckCommand "check_apache_status" {
    import "plugin-check-command"
    command = [ PluginDir + "/check_http" ]
    arguments = {
        "-H" = "$address$"
        "-u" = "/server-status?auto"
    }
}

Step 3: Configure Icinga Server

Define the Host Object: If you haven't already defined the host object for the Apache server in your Icinga configuration, add it:

object Host "apache-server" {
    import "generic-host"
    address = "apache-agent-ip"
    check_command = "hostalive"
}

Define Service for Apache Monitoring: Create a service definition to check Apache status:

apply Service "apache-status" {
    import "generic-service"
    check_command = "apache_status"
    vars.address = "$host.address$"
    assign where host.name == "apache-server"
}

OR

apply Service "apache-status" {
    import "generic-service"
    check_command = "http"
    vars.address = "$host.address$"
    assign where host.name == "apache-server"
}

Reload Icinga 2: After making changes to the configuration files, reload the Icinga 2 service to apply the changes:

sudo systemctl reload icinga2

Step 4: Verify the Configuration

Icinga Web 2: Log into Icinga Web 2 and navigate to the 'Services' section. You should see your new service for monitoring Apache. Verify that it is checking the status as expected.

Troubleshooting: If there are issues, check the Icinga 2 logs for any errors related to the Apache checks. The logs are usually located in /var/log/icinga2/icinga2.log.

Rajesh Kumar

I’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I am working at Cotocus. I blog tech insights at DevOps School, travel stories at Holiday Landmark, stock market tips at Stocks Mantra, health and fitness guidance at My Medic Plus, product reviews at I reviewed , and SEO strategies at Wizbrand. 

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