nixos/tests/turbovnc-headless-server.nix

   1 import ./make-test-python.nix ({ pkgs, lib, ... }: {
   2   name = "turbovnc-headless-server";
   3   meta = {
   4     maintainers = with lib.maintainers; [ nh2 ];
   5   };
   6
   7   nodes.machine = { pkgs, ... }: {
   8
   9     environment.systemPackages = with pkgs; [
  10       mesa-demos
  11       procps # for `pkill`, `pidof` in the test
  12       scrot # for screenshotting Xorg
  13       turbovnc
  14     ];
  15
  16     programs.turbovnc.ensureHeadlessSoftwareOpenGL = true;
  17
  18     networking.firewall = {
  19       # Reject instead of drop, for failures instead of hangs.
  20       rejectPackets = true;
  21       allowedTCPPorts = [
  22         5900 # VNC :0, for seeing what's going on in the server
  23       ];
  24     };
  25
  26     # So that we can ssh into the VM, see e.g.
  27     # https://nixos.org/manual/nixos/stable/#sec-nixos-test-port-forwarding
  28     services.openssh.enable = true;
  29     users.mutableUsers = false;
  30     # `test-instrumentation.nix` already sets an empty root password.
  31     # The following have to all be set to allow an empty SSH login password.
  32     services.openssh.settings.PermitRootLogin = "yes";
  33     services.openssh.settings.PermitEmptyPasswords = "yes";
  34     security.pam.services.sshd.allowNullPassword = true; # the default `UsePam yes` makes this necessary
  35   };
  36
  37   testScript = ''
  38     def wait_until_terminated_or_succeeds(
  39         termination_check_shell_command,
  40         success_check_shell_command,
  41         get_detail_message_fn,
  42         retries=60,
  43         retry_sleep=0.5,
  44     ):
  45         def check_success():
  46             command_exit_code, _output = machine.execute(success_check_shell_command)
  47             return command_exit_code == 0
  48
  49         for _ in range(retries):
  50             exit_check_exit_code, _output = machine.execute(termination_check_shell_command)
  51             is_terminated = exit_check_exit_code != 0
  52             if is_terminated:
  53                 if check_success():
  54                     return
  55                 else:
  56                     details = get_detail_message_fn()
  57                     raise Exception(
  58                         f"termination check ({termination_check_shell_command}) triggered without command succeeding ({success_check_shell_command}); details: {details}"
  59                     )
  60             else:
  61                 if check_success():
  62                     return
  63             import time
  64             time.sleep(retry_sleep)
  65
  66         if not check_success():
  67             details = get_detail_message_fn()
  68             raise Exception(
  69                 f"action timed out ({success_check_shell_command}); details: {details}"
  70             )
  71
  72
  73     # Below we use the pattern:
  74     #     (cmd | tee stdout.log) 3>&1 1>&2 2>&3 | tee stderr.log
  75     # to capture both stderr and stdout while also teeing them, see:
  76     # https://unix.stackexchange.com/questions/6430/how-to-redirect-stderr-and-stdout-to-different-files-and-also-display-in-termina/6431#6431
  77
  78
  79     # Starts headless VNC server, backgrounding it.
  80     def start_xvnc():
  81         xvnc_command = " ".join(
  82             [
  83                 "Xvnc",
  84                 ":0",
  85                 "-iglx",
  86                 "-auth /root/.Xauthority",
  87                 "-geometry 1240x900",
  88                 "-depth 24",
  89                 "-rfbwait 5000",
  90                 "-deferupdate 1",
  91                 "-verbose",
  92                 "-securitytypes none",
  93                 # We don't enforce localhost listening such that we
  94                 # can connect from outside the VM using
  95                 #     env QEMU_NET_OPTS=hostfwd=tcp::5900-:5900 $(nix-build nixos/tests/turbovnc-headless-server.nix -A driver)/bin/nixos-test-driver
  96                 # for testing purposes, and so that we can in the future
  97                 # add another test case that connects the TurboVNC client.
  98                 # "-localhost",
  99             ]
 100         )
 101         machine.execute(
 102             # Note trailing & for backgrounding.
 103             f"({xvnc_command} | tee /tmp/Xvnc.stdout) 3>&1 1>&2 2>&3 | tee /tmp/Xvnc.stderr >&2 &",
 104         )
 105
 106
 107     # Waits until the server log message that tells us that GLX is ready
 108     # (requires `-verbose` above), avoiding screenshoting racing below.
 109     def wait_until_xvnc_glx_ready():
 110         machine.wait_until_succeeds("test -f /tmp/Xvnc.stderr")
 111         wait_until_terminated_or_succeeds(
 112             termination_check_shell_command="pidof Xvnc",
 113             success_check_shell_command="grep 'GLX: Initialized DRISWRAST' /tmp/Xvnc.stderr",
 114             get_detail_message_fn=lambda: "Contents of /tmp/Xvnc.stderr:\n"
 115             + machine.succeed("cat /tmp/Xvnc.stderr"),
 116         )
 117
 118
 119     # Checks that we detect glxgears failing when
 120     # `LIBGL_DRIVERS_PATH=/nonexistent` is set
 121     # (in which case software rendering should not work).
 122     def test_glxgears_failing_with_bad_driver_path():
 123         machine.execute(
 124             # Note trailing & for backgrounding.
 125             "(env DISPLAY=:0 LIBGL_DRIVERS_PATH=/nonexistent glxgears -info | tee /tmp/glxgears-should-fail.stdout) 3>&1 1>&2 2>&3 | tee /tmp/glxgears-should-fail.stderr >&2 &"
 126         )
 127         machine.wait_until_succeeds("test -f /tmp/glxgears-should-fail.stderr")
 128         wait_until_terminated_or_succeeds(
 129             termination_check_shell_command="pidof glxgears",
 130             success_check_shell_command="grep 'MESA-LOADER: failed to open swrast' /tmp/glxgears-should-fail.stderr",
 131             get_detail_message_fn=lambda: "Contents of /tmp/glxgears-should-fail.stderr:\n"
 132             + machine.succeed("cat /tmp/glxgears-should-fail.stderr"),
 133         )
 134         machine.wait_until_fails("pidof glxgears")
 135
 136
 137     # Starts glxgears, backgrounding it. Waits until it prints the `GL_RENDERER`.
 138     # Does not quit glxgears.
 139     def test_glxgears_prints_renderer():
 140         machine.execute(
 141             # Note trailing & for backgrounding.
 142             "(env DISPLAY=:0 glxgears -info | tee /tmp/glxgears.stdout) 3>&1 1>&2 2>&3 | tee /tmp/glxgears.stderr >&2 &"
 143         )
 144         machine.wait_until_succeeds("test -f /tmp/glxgears.stderr")
 145         wait_until_terminated_or_succeeds(
 146             termination_check_shell_command="pidof glxgears",
 147             success_check_shell_command="grep 'GL_RENDERER' /tmp/glxgears.stdout",
 148             get_detail_message_fn=lambda: "Contents of /tmp/glxgears.stderr:\n"
 149             + machine.succeed("cat /tmp/glxgears.stderr"),
 150         )
 151
 152
 153     with subtest("Start Xvnc"):
 154         start_xvnc()
 155         wait_until_xvnc_glx_ready()
 156
 157     with subtest("Ensure bad driver path makes glxgears fail"):
 158         test_glxgears_failing_with_bad_driver_path()
 159
 160     with subtest("Run 3D application (glxgears)"):
 161         test_glxgears_prints_renderer()
 162
 163         # Take screenshot; should display the glxgears.
 164         machine.succeed("scrot --display :0 /tmp/glxgears.png")
 165
 166     # Copy files down.
 167     machine.copy_from_vm("/tmp/glxgears.png")
 168     machine.copy_from_vm("/tmp/glxgears.stdout")
 169     machine.copy_from_vm("/tmp/glxgears-should-fail.stdout")
 170     machine.copy_from_vm("/tmp/glxgears-should-fail.stderr")
 171     machine.copy_from_vm("/tmp/Xvnc.stdout")
 172     machine.copy_from_vm("/tmp/Xvnc.stderr")
 173   '';
 174
 175 })