UNBLOCK (for denyhost)
Tool to unblock an IP address if it has been blocked by the denyhost daemon
git clone https://github.com/rsprabery/unblock.git cd unblock sudo python unblock.py IP_ADDRESS
IP_ADDRESS is the IP address that is currently blocked by denyhost.
Usage is currently limited to the local machine only (which will be the use case for singly owned servers). So if you've locked yourself out of your VPS you'll have to get access via a web-shell or similar and then run this program.
In denyhosts folder (limited to /var/lib/denyhost at the moment)
Other system files modified
http://www.cyberciti.biz/faq/linux-unix-delete-remove-ip-address-that-denyhosts-blocked/ for providing information on how to remove an IP from being blocked; this utility is based on that blog post.