check_public_ip.py

Update Version 0.3:
This is a lot more robust now, it tries multiple sites, if any are overloaded it can return None, so try the next, if any are down, or don't exist it should catch this IOError and try the next site in the tuple.

There is a line in the script:
site_list = ('http://curlmyip.com','http://icanhazip.com')

You can add your own site to this list, preferably put it first in the above tuple, otherwise 35000 people all issuing GET requests every few minutes to the above sites may overload them.

Copy ip.php to a remote webserver, chown the file to www-data, and add your site to the above tuple:
site_list = ('http://mysite.com/ip.php','http://curlmyip.com','http://icanhazip.com')

Also in the main script replace 1.2.3.4 with your own main public IP, and replace 5.6.7.8 with your backup internet public IP.




Nagios instructions:
Copy check_public_ip.py to your nagios/libexec folder.

add this command to commands.cfg:

define command{
command_name check_failover_internet
command_line $USER1$/check_public_ip.py
}



add this service check to your firewall.cfg host, and change myfirewall to whatever you've named yours:

define service{
use generic-service ;
host_name myfirewall ;
service_description Active Internet Connection ;
check_command check_failover_internet
max_check_attempts 2

}