NAGIOS: check_http: Invalid option - SSL is not available

When attempting to monitor an SSL / HTTPS site with the check_http command within NAGIOS I encountered the following error:

check_http: Invalid option - SSL is not available

This is because the openssl development libraries were not available during the initial compilation of the NAGIOS plugins - to resolve this we should install the relevent packages and recompile them:

yum install openssl-devel

wget http://www.nagios-plugins.org/download/nagios-plugins-2.1.1.tar.gz

tar zxvf nagios-plugins-2.1.1.tar.gz

cd nagios-plugins-2*

./configure --with-openssl --with-nagios-user=nagios --with-nagios-group=nagios

make all

make install