Various nagios plugins I've written over the years
check_logstash.sh - Checks and alerts if Logstash is not logging to Elasticsearch
check_puppet.sh - Alerts if the Puppet agent not running, or is disabled.
check_pvgrub.sh - Check if any physical drive is NOT present in /boot/grub/device.map
check_hvm.sh - Check if kernel version is 3.1X and alerts if HVM is not set
check_sockets.sh - Check the number of sockets an application (Docker by default) is using and warn / alert if over a threshold
check_mdadm.sh - Check Linux RAID (mdadm) status.
check_redmine_queue.sh - Check a Redmine queue for urgent tickets.