Extensions installed into chromium using the os config carry over to ungoogled-chromium.
This makes it possible to install extensions for ungoogled chromium without having to download them manually.
First add extensions to chromium like this:
environment.systemPackages = with pkgs; [ chromium ];
programs.chromium = {
enable = true;
extensions = [ "cjpalhdlnbpafiamejdnhcphjbkeiagm" # ublock origin ];
};
Run nixos-rebuild switch.
Change the chromium package to ungoogled chromium and rebuild again:
environment.systemPackages = with pkgs; [ ungoogled-chromium ];
This could probably be improved upon…