https://github.com/freifunk-gluon/gluon

https://github.com/freifunk-gluon/gluon/wiki
Gluon is a modular framework to build wired and wireless mesh networks, based 
on the popular OpenWrt distribution. It is widely used among the german 
Freifunk community and thus battle-tested.

https://gluon.readthedocs.io/en/latest/
https://gluon.readthedocs.io/en/latest/user/getting_started.html
If you're new to Gluon and ready to get your feet wet, have a look at the 
Getting Started Guide.