Tony Finch – blog

I have made a new release of nsnotifyd a tiny DNS server that just listens for NOTIFY messages and runs a script when one of your zones changes.

This nsnotifyd-2.0 release adds support for TCP. The original nsnotifyd only supported UDP, which works fine with BIND, but Knot DNS sends NOTIFY messages over TCP.

As well as its new TCP support, the nsnotify client program that sends NOTIFY messages can now send bulk notifications for lots of zones, as well as being able to send notifications to lots of recipient servers.

Many thanks to Niels Haarbo and DK Hostmaster for requesting TCP support and for sponsoring my work to implement it.

I like nsnotifyd because I wrote it in 2015, and I haven’t touched it since then (until this month). I usually hear nothing about nsnotifyd, but occasionally someone mentions they are using it. For example the Guardian tech blog said of nsnotifyd, “like all good *nix tools it does one thing well”, and JP Mens called it “a gem of a utility”.

Happy users, no bug reports, software bliss.