Create a wifi accesspoint (sharing wifi) with traffic routed over VPN

Question

I know we can create a wifi hotspot, sharing ethernet over wifi but is there a way I can create a new wifi hotspot while staying connected to a wifi. So something like sharing wifi.

My use case is I am using a VPN, which creates a new interface ppp0. I want to create a new wifi access point whose traffic will be sent over the VPN(on the ppp0 interface).

Trying to setup something like:

(Internet) --- (home router wifi) --- (raspberry pi connected over wifi) --- (wifi accesspoint on raspberry pi, routing traffic over VPN) --- (my other gadgets)

Answer 1

It is possible to create a WiFi router/repeater with a WiFi uplink to your internet router. How to do it you can look at Access point as WiFi router/repeater, optional with bridge.

If you have this running then based on this you should be able to create an additional VPN tunnel, either with using a Simple openVPN with static keys, or using Wireguard, or install PiVPN. I do not know if it is possible to integrate PiVPN into the WiFi repeater setup. Maybe there are preconditions set by PiVPN which do not fit.

I would prefer Wireguard because it is simple to use and very well integrated into systemd-networkd, that is in general used for the WiFi repeater setup.