nixos-config/nixos/system/all/borg-scripts.nix

{ pkgs, lib, ... }: {

  environment.systemPackages =
    let
      createScript = command: host: repository:
        pkgs.writers.writeBashBin
          "borg-${command}-on-${host}-for-${repository}" ''
          ${pkgs.borgbackup}/bin/borg \
            ${command} \
            --rsh='ssh -i ~/.ssh/card_rsa.pub' borg@${host}.private:${repository}/. \
            "$@"
        '';
      hosts = [ "pepe" "robi" ];
      repositories = [ "pepe" "sterni" "robi" ];
      commands = [ "list" ];
    in
    lib.flatten (map
      (command:
        map
          (host: map (repository: createScript command host repository) repositories)
          hosts)
      commands);

}