nixos/vaultwarden: create backupDir using tmpfiles.d

#!/usr/bin/env bash

# Based on: https://github.com/dani-garcia/vaultwarden/wiki/Backing-up-your-vault

if ! mkdir -p "$BACKUP_FOLDER"; then

  echo "Could not create backup folder '$BACKUP_FOLDER'" >&2

if [ ! -d "$BACKUP_FOLDER" ]; then

  echo "Backup folder '$BACKUP_FOLDER' does not exist" >&2

  exit 1

fi

      };

      wantedBy = [ "multi-user.target" ];

    };

    systemd.tmpfiles.settings = mkIf (cfg.backupDir != null) {

      "10-vaultwarden".${cfg.backupDir}.d = {

        inherit user group;

        mode = "0770";

      };

    };

  };

  # uses attributes of the linked package