diff options
Diffstat (limited to 'nixpkgs/nixos/modules/testing/test-instrumentation.nix')
-rw-r--r-- | nixpkgs/nixos/modules/testing/test-instrumentation.nix | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/testing/test-instrumentation.nix b/nixpkgs/nixos/modules/testing/test-instrumentation.nix new file mode 100644 index 000000000000..ed4cfa7805e2 --- /dev/null +++ b/nixpkgs/nixos/modules/testing/test-instrumentation.nix @@ -0,0 +1,137 @@ +# This module allows the test driver to connect to the virtual machine +# via a root shell attached to port 514. + +{ config, lib, pkgs, ... }: + +with lib; +with import ../../lib/qemu-flags.nix { inherit pkgs; }; + +{ + + # This option is a dummy that if used in conjunction with + # modules/virtualisation/qemu-vm.nix gets merged with the same option defined + # there and only is declared here because some modules use + # test-instrumentation.nix but not qemu-vm.nix. + # + # One particular example are the boot tests where we want instrumentation + # within the images but not other stuff like setting up 9p filesystems. + options.virtualisation.qemu.program = mkOption { type = types.path; }; + + config = { + + systemd.services.backdoor = + { wantedBy = [ "multi-user.target" ]; + requires = [ "dev-hvc0.device" "dev-${qemuSerialDevice}.device" ]; + after = [ "dev-hvc0.device" "dev-${qemuSerialDevice}.device" ]; + script = + '' + export USER=root + export HOME=/root + export DISPLAY=:0.0 + + source /etc/profile + + # Don't use a pager when executing backdoor + # actions. Because we use a tty, commands like systemctl + # or nix-store get confused into thinking they're running + # interactively. + export PAGER= + + cd /tmp + exec < /dev/hvc0 > /dev/hvc0 + while ! exec 2> /dev/${qemuSerialDevice}; do sleep 0.1; done + echo "connecting to host..." >&2 + stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion + echo + PS1= exec /bin/sh + ''; + serviceConfig.KillSignal = "SIGHUP"; + }; + + # Prevent agetty from being instantiated on the serial device, since it + # interferes with the backdoor (writes to it will randomly fail + # with EIO). Likewise for hvc0. + systemd.services."serial-getty@${qemuSerialDevice}".enable = false; + systemd.services."serial-getty@hvc0".enable = false; + + # Only use a serial console, no TTY. + virtualisation.qemu.consoles = [ qemuSerialDevice ]; + + boot.initrd.preDeviceCommands = + '' + echo 600 > /proc/sys/kernel/hung_task_timeout_secs + ''; + + boot.initrd.postDeviceCommands = + '' + # Using acpi_pm as a clock source causes the guest clock to + # slow down under high host load. This is usually a bad + # thing, but for VM tests it should provide a bit more + # determinism (e.g. if the VM runs at lower speed, then + # timeouts in the VM should also be delayed). + echo acpi_pm > /sys/devices/system/clocksource/clocksource0/current_clocksource + ''; + + boot.postBootCommands = + '' + # Panic on out-of-memory conditions rather than letting the + # OOM killer randomly get rid of processes, since this leads + # to failures that are hard to diagnose. + echo 2 > /proc/sys/vm/panic_on_oom + + # Coverage data is written into /tmp/coverage-data. + mkdir -p /tmp/xchg/coverage-data + ''; + + # If the kernel has been built with coverage instrumentation, make + # it available under /proc/gcov. + boot.kernelModules = [ "gcov-proc" ]; + + # Panic if an error occurs in stage 1 (rather than waiting for + # user intervention). + boot.kernelParams = + [ "console=${qemuSerialDevice}" "panic=1" "boot.panic_on_fail" ]; + + # `xwininfo' is used by the test driver to query open windows. + environment.systemPackages = [ pkgs.xorg.xwininfo ]; + + # Log everything to the serial console. + services.journald.extraConfig = + '' + ForwardToConsole=yes + MaxLevelConsole=debug + ''; + + systemd.extraConfig = '' + # Don't clobber the console with duplicate systemd messages. + ShowStatus=no + # Allow very slow start + DefaultTimeoutStartSec=300 + ''; + + boot.consoleLogLevel = 7; + + # Prevent tests from accessing the Internet. + networking.defaultGateway = mkOverride 150 ""; + networking.nameservers = mkOverride 150 [ ]; + + systemd.globalEnvironment.GCOV_PREFIX = "/tmp/xchg/coverage-data"; + + system.requiredKernelConfig = with config.lib.kernelConfig; [ + (isYes "SERIAL_8250_CONSOLE") + (isYes "SERIAL_8250") + (isEnabled "VIRTIO_CONSOLE") + ]; + + networking.usePredictableInterfaceNames = false; + + # Make it easy to log in as root when running the test interactively. + users.users.root.initialHashedPassword = mkOverride 150 ""; + + services.xserver.displayManager.job.logToJournal = true; + + # set default stateVersion to avoid warnings during eval + system.stateVersion = mkDefault "18.03"; + }; + +} |