Mesh Networking
Nebula as a mesh network choice potentially.
Just a quick note, nebula doesn't inherently require being run as root, as long as you allow it to do network-things. This is easily done with setcap with the CAP_NET_ADMIN capability, i.e. you can do:
sudo setcap cap_net_admin+ep /usr/local/bin/nebula
...and then you can run it as any user you like. Just make sure the nebula configuration and creds are readable by that user.