Check Overall System Health

Checks the following:
- 15 minute load (warning or critical)
- Swap useage (warning or critical)
- All locally mounted partitions useage % (warning or critical)
- RAM useage % (warn only)
- CPU useage % (just a "nice to know", no warnings)

Tested on Ubuntu 11.10, 10.04 and Debian 6 running Python 2.7.2+

Note: if you're getting an error about unable to change to float, your hostname may be wrong.

Example command definition:

# system_check command, see /usr/lib/nagios/plugins/system_check
# for more information.
define command {
command_name system_check
command_line /usr/lib/nagios/plugins/system_check -H $HOSTADDRESS$ -U $ARG1$ -l $ARG2$ -L $ARG3$ -d $ARG4$ -D $ARG5$ -r $ARG6$ -s $ARG7$ -S $ARG8$
}

Example service definition:

define service {
use generic-nograph-service
hostgroup_name mongo-servers
service_description System Check
check_command system_check!mongoadmin!8.00!10.00!80!95!95!102400!204800
}