FirejailedFox

ff.nix

{ config, pkgs, lib, ... }:
{
  nixpkgs.overlays = [
    (self: super: {
      firejailedFirefox = super.stdenv.mkDerivation rec {
        name = "firejailed-firefox-desktop-item";
        dontBuild = true;
        unpackPhase = "true";

        desktopItem = super.makeDesktopItem {
          name = "firefox";
          exec = "/run/current-system/sw/bin/firefox";
          genericName = "Web Browser";
          categories = "Application;Network;WebBrowser;";
          desktopName = "firefox";
          mimeType = lib.concatStringsSep ";" [
            "text/html"
            "text/xml"
            "application/xhtml+xml"
            "application/vnd.mozilla.xul+xml"
            "x-scheme-handler/http"
            "x-scheme-handler/https"
            "x-scheme-handler/ftp"
          ];
        };

        installPhase = ''
          mkdir -p $out/share
          cp -r ${desktopItem}/share/applications $out/share
        '';
      };
    })
  ];

  programs.firejail = {
    enable = true;
    wrappedBinaries.firefox = "${pkgs.lib.getBin pkgs.firefox}/bin/firefox";
  };
  
  # or users packages
  environment.systemPackages = [ firejailedFirefox ];
}