infra/nix/os/containers/syncthing.nix

{
  specialArgs,
  hostBridge,
  hostAddress,
  localAddress,
  syncthingPort ? 22000,
  syncthingLocalAnnouncePort ? 21027,
  autoStart ? false,
}:
{
  inherit specialArgs;
  config =
    { ... }:
    {
      system.stateVersion = "20.05"; # Did you read the comment?

      imports = [ ../profiles/containers/configuration.nix ];

      networking.firewall.allowedTCPPorts = [
        # syncthing gui
        8384
      ];

      services.syncthing = {
        enable = true;
        openDefaultPorts = true;
        guiAddress = "0.0.0.0:8384";
      };
    };

  inherit autoStart;

  bindMounts = {
    "/var/lib/syncthing/" = {
      hostPath = "/var/lib/container-volumes/syncthing/var-lib-syncthing";
      isReadOnly = false;
    };
  };

  privateNetwork = true;
  forwardPorts = [
    {
      containerPort = 22000;
      hostPort = syncthingPort;
      protocol = "tcp";
    }
    {
      containerPort = 22000;
      hostPort = syncthingPort;
      protocol = "udp";
    }
    {
      containerPort = 21027;
      hostPort = syncthingLocalAnnouncePort;
      protocol = "udp";
    }
  ];

  inherit hostBridge hostAddress localAddress;
}