How to Compile NRPE With an SSL Option

Nagios is a sophisticated program designed to make it easy for Linux administrators to monitor dozens or even hundreds of systems from one computer. NRPE is an add on designed to allow you to monitor even local resources, like CPU load and memory usage, on those machines.

Instructions

1. Download both the Nagios Core and the Nagios Plugins from the project home page, as well as the NRPE add on (see Resources). The core contains the program itself, while the plugins contain common extra features including support for SSL.

2. Open a terminal and navigate to the directory where downloaded the Nagios Core using the following command:

   cd ~/Downloads/nagios-3.2.3

   Replace the path with the path where you made the download.

3. Type the following three commands to configure, compile and install the Nagios Core:

   ./configure

   make

   make install

4. Navigate to the directory where downloaded the plugins package using the following command:

   cd ../nagios-plugins-1.4.15

5. Type the following:

   ./configure > config_log; cat config_log | egrep "ssl|SSL"

   This command is a little more sophisticated than the last one: it runs the "configure" script and sends the output to the file "config_log." As soon as it finished, it searches the config_log using the "cat" and "grep" commands for the word "SSL" and prints only those lines. If the lines all read "yes," everything is configured to use SSL. If any of them read "no," then you need to download and install the latest version of OpenSSL.

   If the Nagios Plugins are not configured to use SSL, NRPE will not work with SSL either.

6. Type the following command to build and install the Nagios plugins:

   make

   make install

7. Type the following to navigate to the NRPE folder:

   cd ../nrpe-2.12

8. Type the same command that you used in step 5:

   ./configure > config_log; cat config_log | egrep "ssl|SSL"

   If it fails, but you have OpenSSL installed, you may need to specify the directory manually by typing:

   ./configure --with-ssl-lib=/usr/lib > config_log; cat config_log | egrep "ssl|SSL"

Tips & Warnings

• In steps 5 and 8, the "|" is the pipe symbol (Shift-\), not a lowercase l or uppercase i.

References

• Utah Sys Admin: Build with SSL Support