Installing NRPE

1. Refresh the repository:

   sudo apt-get update

2. Install the dependencies:

   sudo apt-get install libssl-dev -y

3. Change the directory to your home directory:

   cd ~

4. Download the nrpe 4 source codes:

   wget https://github.com/NagiosEnterprises/nrpe/releases/download/nrpe-4.0.3/nrpe-4.0.3.tar.gz

5. Extract the downloaded source codes:

   tar xvf nrpe-4.0.3.tar.gz

6. Change to the directory of the newly extracted source codes:

   cd nrpe-4.0.3

7. Run the configure script:

   ./configure

8. Compile the check_nrpe plugin only:

   sudo make check_nrpe

9. Install the newly compiled plugin:

   sudo make install-plugin

10. Update the file /usr/local/nagios/etc/objects/commands.cfg to add the following entry:

    define command {
    	command_name    check_nrpe
    	command_line    /usr/local/nagios/libexec/check_nrpe -H $HOSTADDRESS$ -t 30 -c $ARG1$ $ARG2$
    }

Testing The Plugin

Using the command check_nrpe we can check the load on the host 10.0.0.202 (i.e. NRPE daemon must be configured and listening on port 5666) using the following command:

/usr/local/nagios/libexec/check_nrpe -H 10.0.0.202 -c check_load

Expect to see the output of the check_load plugin executed on the host 10.0.0.202