Nagios check for ssl certificate validation
This is a check for any Nagios compliant monitorization tool to check SSL certificates. It must be run in the local server using NRPE or similar check plugins.
This nagios check requires Perl and some modules. This is the debian and derivates installation guide, other distributions should be similar:
sudo apt install libdatetime-format-dateparse-perl libdatetime libdate-calc-perl libipc-run3-perl
Copy the file to a nagios plugins directory like /usr/lib/nagios/plugins
sudo cp check_certificate_ssl /usr/lib/nagios/plugins