The “Meta for Developers” blog has an
introduction to the drgn kernel debugger.
drgn (pronounced “dragon”) is a debugger that exposes the types and
variables in a program for easy, expressive scripting in
Python. The Linux kernel team at Meta originally built drgn to make
it easier to investigate the kinds of difficult Linux kernel bugs
that the team encounters at Meta. The team has since added further
use cases for it, like monitoring and userspace memory profiling.
LWN reported on drgn in 2019.