Nagios Plugin for SSL Certificate expiry Checks

Download

http://exchange.nagios.org/directory/Plugins/Network-Protocols/HTTP/check_ssl_cert/details

Installation

Copy the check_ssl_cert ( nagios Plugin ) in /usr/local/nagios/libexec/ directory

make it executable and owned by nagios user

chmod 755 /usr/local/nagios/libexec/check_ssl_cert
chown nagios.nagios /usr/local/nagios/libexec/check_ssl_cert

Then check an site / zimbra admin which has ssl certificate with command line , example for Zimbra internal certificate is shown below

/usr/local/nagios/libexec/check_ssl_cert -H webmail.phdcci.in -A -p 7071

you will get a response like

SSL_CERT OK - X.509 certificate for 'webmail.phdcci.in' from 'webmail.phdcci.in' valid until May  3 15:58:02 2014 GMT

This gives the expiry date too. ( -A option is for not to check valid authority , -p is for specifying the port address )

Now , Please create a command for nagios in /usr/local/nagios/etc/objects/command.cfg as shown below

define command {
      command_name                             check_ssl_certificate_expiry
      command_line                             $USER1$/check_ssl_cert -H $HOSTADDRESS$ -A -p $ARG1$
}

Reload the nagios with

service nagios reload

Configuration

Now you are ready to configure services to check the ssl expiry . So add the following line in the host/service configuration files of the concerning hosts

define service {
              use                      generic-service
              host_name                webmail.phdcci.in
              service_description     SSL Certificate Expiry
              notification_options    w,u,c,r
              check_command            check_ssl_certificate_expiry!7071
             }

Reload the Nagios service .

Check the environment on the web GUI of Nagios