Utility to dynamically reconfigure /etc/resolv.conf based on performance or availability.

In August of 2014 Charter Communications suffered a DNS outage, at least from my perspective. I used google's public DNS services to ride out the outage and when my dhclient refreshed my IP addresses the changes were replaced as expected with those retrieved from the ISP. I could of course use prepend statements in the /etc/dhclient.conf, but I wanted something that would check what my ISP had given me against what others were publicly available and update my /etc/resolv.conf as needed based on lookup times and availability. Thus this script was born. Setup and periodically run in a cron job.

There is probably a better way to do this, but hey writing python is fun right?

• dnspython http://www.dnspython.org/
• yaml http://pyyaml.org/

Drop purgo.py and purgo.cfg on a box and run. Use --help for options.

Resolv.conf can have up to three nameserver entries for which it tries one by one waiting for a timeout. This utility tries to ensure that those three entries will be the best that they can be.

Not heavily tested and it needs to run as root to modify /etc/resolv.conf. Use at your own risk!