nixpkgs/nixos/tests/bittorrent.nix

# This test runs a Bittorrent tracker on one machine, and verifies
# that two client machines can download the torrent using
# `transmission'.  The first client (behind a NAT router) downloads
# from the initial seeder running on the tracker.  Then we kill the
# initial seeder.  The second client downloads from the first client,
# which only works if the first client successfully uses the UPnP-IGD
# protocol to poke a hole in the NAT.

import ./make-test-python.nix (
  { pkgs, ... }:

  let

    # Some random file to serve.
    file = pkgs.hello.src;

    internalRouterAddress = "192.168.3.1";
    internalClient1Address = "192.168.3.2";
    externalRouterAddress = "80.100.100.1";
    externalClient2Address = "80.100.100.2";
    externalTrackerAddress = "80.100.100.3";

    download-dir = "/var/lib/transmission/Downloads";
    transmissionConfig =
      { pkgs, ... }:
      {
        environment.systemPackages = [ pkgs.transmission_3 ];
        services.transmission = {
          enable = true;
          settings = {
            dht-enabled = false;
            message-level = 2;
            inherit download-dir;
          };
        };
      };
  in

  {
    name = "bittorrent";
    meta = with pkgs.lib.maintainers; {
      maintainers = [
        domenkozar
        rob
        bobvanderlinden
      ];
    };

    nodes = {
      tracker =
        { pkgs, ... }:
        {
          imports = [ transmissionConfig ];

          virtualisation.vlans = [ 1 ];
          networking.firewall.enable = false;
          networking.interfaces.eth1.ipv4.addresses = [
            {
              address = externalTrackerAddress;
              prefixLength = 24;
            }
          ];

          # We need Apache on the tracker to serve the torrents.
          services.httpd = {
            enable = true;
            virtualHosts = {
              "torrentserver.org" = {
                adminAddr = "foo@example.org";
                documentRoot = "/tmp";
              };
            };
          };
          services.opentracker.enable = true;
        };

      router =
        { pkgs, nodes, ... }:
        {
          virtualisation.vlans = [
            1
            2
          ];
          networking.nat.enable = true;
          networking.nat.internalInterfaces = [ "eth2" ];
          networking.nat.externalInterface = "eth1";
          networking.firewall.enable = true;
          networking.firewall.trustedInterfaces = [ "eth2" ];
          networking.interfaces.eth0.ipv4.addresses = [ ];
          networking.interfaces.eth1.ipv4.addresses = [
            {
              address = externalRouterAddress;
              prefixLength = 24;
            }
          ];
          networking.interfaces.eth2.ipv4.addresses = [
            {
              address = internalRouterAddress;
              prefixLength = 24;
            }
          ];
          services.miniupnpd = {
            enable = true;
            externalInterface = "eth1";
            internalIPs = [ "eth2" ];
            appendConfig = ''
              ext_ip=${externalRouterAddress}
            '';
          };
        };

      client1 =
        { pkgs, nodes, ... }:
        {
          imports = [ transmissionConfig ];
          environment.systemPackages = [ pkgs.miniupnpc ];

          virtualisation.vlans = [ 2 ];
          networking.interfaces.eth0.ipv4.addresses = [ ];
          networking.interfaces.eth1.ipv4.addresses = [
            {
              address = internalClient1Address;
              prefixLength = 24;
            }
          ];
          networking.defaultGateway = internalRouterAddress;
          networking.firewall.enable = false;
        };

      client2 =
        { pkgs, ... }:
        {
          imports = [ transmissionConfig ];

          virtualisation.vlans = [ 1 ];
          networking.interfaces.eth0.ipv4.addresses = [ ];
          networking.interfaces.eth1.ipv4.addresses = [
            {
              address = externalClient2Address;
              prefixLength = 24;
            }
          ];
          networking.firewall.enable = false;
        };
    };

    testScript =
      { nodes, ... }:
      ''
        start_all()

        # Wait for network and miniupnpd.
        router.systemctl("start network-online.target")
        router.wait_for_unit("network-online.target")
        router.wait_for_unit("miniupnpd")

        # Create the torrent.
        tracker.succeed("mkdir ${download-dir}/data")
        tracker.succeed(
            "cp ${file} ${download-dir}/data/test.tar.bz2"
        )
        tracker.succeed(
            "transmission-create ${download-dir}/data/test.tar.bz2 --private --tracker http://${externalTrackerAddress}:6969/announce --outfile /tmp/test.torrent"
        )
        tracker.succeed("chmod 644 /tmp/test.torrent")

        # Start the tracker.  !!! use a less crappy tracker
        tracker.systemctl("start network-online.target")
        tracker.wait_for_unit("network-online.target")
        tracker.wait_for_unit("opentracker.service")
        tracker.wait_for_open_port(6969)

        # Start the initial seeder.
        tracker.succeed(
            "transmission-remote --add /tmp/test.torrent --no-portmap --no-dht --download-dir ${download-dir}/data"
        )

        # Now we should be able to download from the client behind the NAT.
        tracker.wait_for_unit("httpd")
        client1.systemctl("start network-online.target")
        client1.wait_for_unit("network-online.target")
        client1.succeed("transmission-remote --add http://${externalTrackerAddress}/test.torrent >&2 &")
        client1.wait_for_file("${download-dir}/test.tar.bz2")
        client1.succeed(
            "cmp ${download-dir}/test.tar.bz2 ${file}"
        )

        # Bring down the initial seeder.
        tracker.stop_job("transmission")

        # Now download from the second client.  This can only succeed if
        # the first client created a NAT hole in the router.
        client2.systemctl("start network-online.target")
        client2.wait_for_unit("network-online.target")
        client2.succeed(
            "transmission-remote --add http://${externalTrackerAddress}/test.torrent --no-portmap --no-dht >&2 &"
        )
        client2.wait_for_file("${download-dir}/test.tar.bz2")
        client2.succeed(
            "cmp ${download-dir}/test.tar.bz2 ${file}"
        )
      '';
  }
)