Merge pull request #256226 from ElvishJerricco/systemd-stage-1-testing-backdoor

Changed files
+213 -140
nixos
+2
nixos/doc/manual/release-notes/rl-2311.section.md
···
- `teleport` has been upgraded from major version 12 to major version 14. Please see upstream [upgrade instructions](https://goteleport.com/docs/management/operations/upgrading/) and release notes for versions [13](https://goteleport.com/docs/changelog/#1300-050823) and [14](https://goteleport.com/docs/changelog/#1400-092023). Note that Teleport does not officially support upgrades across more than one major version at a time. If you're running Teleport server components, it is recommended to first upgrade to an intermediate 13.x version by setting `services.teleport.package = pkgs.teleport_13`. Afterwards, this option can be removed to upgrade to the default version (14).
- The Linux kernel module `msr` (see [`msr(4)`](https://man7.org/linux/man-pages/man4/msr.4.html)), which provides an interface to read and write the model-specific registers (MSRs) of an x86 CPU, can now be configured via `hardware.cpu.x86.msr`.
+
+
- There is a new NixOS option when writing NixOS tests `testing.initrdBackdoor`, that enables `backdoor.service` in initrd. Requires `boot.initrd.systemd.enable` to be enabled. Boot will pause in stage 1 at `initrd.target`, and will listen for commands from the `Machine` python interface, just like stage 2 normally does. This enables commands to be sent to test and debug stage 1. Use `machine.switch_root()` to leave stage 1 and proceed to stage 2.
+16
nixos/lib/test-driver/test_driver/machine.py
···
def run_callbacks(self) -> None:
for callback in self.callbacks:
callback()
+
+
def switch_root(self) -> None:
+
"""
+
Transition from stage 1 to stage 2. This requires the
+
machine to be configured with `testing.initrdBackdoor = true`
+
and `boot.initrd.systemd.enable = true`.
+
"""
+
self.wait_for_unit("initrd.target")
+
self.execute(
+
"systemctl isolate --no-block initrd-switch-root.target 2>/dev/null >/dev/null",
+
check_return=False,
+
check_output=False,
+
)
+
self.wait_for_console_text(r"systemd\[1\]:.*Switching root\.")
+
self.connected = False
+
self.connect()
+93 -41
nixos/modules/testing/test-instrumentation.nix
···
with lib;
let
+
cfg = config.testing;
+
qemu-common = import ../../lib/qemu-common.nix { inherit lib pkgs; };
+
+
backdoorService = {
+
wantedBy = [ "sysinit.target" ];
+
unitConfig.DefaultDependencies = false;
+
conflicts = [ "shutdown.target" "initrd-switch-root.target" ];
+
before = [ "shutdown.target" "initrd-switch-root.target" ];
+
requires = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
+
after = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
+
script =
+
''
+
export USER=root
+
export HOME=/root
+
export DISPLAY=:0.0
+
+
if [[ -e /etc/profile ]]; then
+
source /etc/profile
+
fi
+
+
# 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/${qemu-common.qemuSerialDevice}; do sleep 0.1; done
+
echo "connecting to host..." >&2
+
stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
+
# The following line is essential since it signals to
+
# the test driver that the shell is ready.
+
# See: the connect method in the Machine class.
+
echo "Spawning backdoor root shell..."
+
# Passing the terminal device makes bash run non-interactively.
+
# Otherwise we get errors on the terminal because bash tries to
+
# setup things like job control.
+
# Note: calling bash explicitly here instead of sh makes sure that
+
# we can also run non-NixOS guests during tests.
+
PS1= exec /usr/bin/env bash --norc /dev/hvc0
+
'';
+
serviceConfig.KillSignal = "SIGHUP";
+
};
+
in
{
+
options.testing = {
+
+
initrdBackdoor = lib.mkEnableOption (lib.mdDoc ''
+
enable backdoor.service in initrd. Requires
+
boot.initrd.systemd.enable to be enabled. Boot will pause in
+
stage 1 at initrd.target, and will listen for commands from the
+
Machine python interface, just like stage 2 normally does. This
+
enables commands to be sent to test and debug stage 1. Use
+
machine.switch_root() to leave stage 1 and proceed to stage 2.
+
'');
+
+
};
+
config = {
-
systemd.services.backdoor =
-
{ wantedBy = [ "multi-user.target" ];
-
requires = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
-
after = [ "dev-hvc0.device" "dev-${qemu-common.qemuSerialDevice}.device" ];
-
script =
-
''
-
export USER=root
-
export HOME=/root
-
export DISPLAY=:0.0
+
assertions = [
+
{
+
assertion = cfg.initrdBackdoor -> config.boot.initrd.systemd.enable;
+
message = ''
+
testing.initrdBackdoor requires boot.initrd.systemd.enable to be enabled.
+
'';
+
}
+
];
-
source /etc/profile
+
systemd.services.backdoor = backdoorService;
+
+
boot.initrd.systemd = lib.mkMerge [
+
{
+
contents."/etc/systemd/journald.conf".text = ''
+
[Journal]
+
ForwardToConsole=yes
+
MaxLevelConsole=debug
+
'';
+
+
extraConfig = config.systemd.extraConfig;
+
}
+
+
(lib.mkIf cfg.initrdBackdoor {
+
# Implemented in machine.switch_root(). Suppress the unit by
+
# making it a noop without removing it, which would break
+
# initrd-parse-etc.service
+
services.initrd-cleanup.serviceConfig.ExecStart = [
+
# Reset
+
""
+
# noop
+
"/bin/true"
+
];
-
# Don't use a pager when executing backdoor
-
# actions. Because we use a tty, commands like systemctl
-
# or nix-store get confused into thinking they're running
-
# interactively.
-
export PAGER=
+
services.backdoor = backdoorService;
-
cd /tmp
-
exec < /dev/hvc0 > /dev/hvc0
-
while ! exec 2> /dev/${qemu-common.qemuSerialDevice}; do sleep 0.1; done
-
echo "connecting to host..." >&2
-
stty -F /dev/hvc0 raw -echo # prevent nl -> cr/nl conversion
-
# The following line is essential since it signals to
-
# the test driver that the shell is ready.
-
# See: the connect method in the Machine class.
-
echo "Spawning backdoor root shell..."
-
# Passing the terminal device makes bash run non-interactively.
-
# Otherwise we get errors on the terminal because bash tries to
-
# setup things like job control.
-
# Note: calling bash explicitly here instead of sh makes sure that
-
# we can also run non-NixOS guests during tests.
-
PS1= exec /usr/bin/env bash --norc /dev/hvc0
-
'';
-
serviceConfig.KillSignal = "SIGHUP";
-
};
+
contents."/usr/bin/env".source = "${pkgs.coreutils}/bin/env";
+
})
+
];
# Prevent agetty from being instantiated on the serial device, since it
# interferes with the backdoor (writes to it will randomly fail
···
MaxLevelConsole=debug
'';
-
boot.initrd.systemd.contents."/etc/systemd/journald.conf".text = ''
-
[Journal]
-
ForwardToConsole=yes
-
MaxLevelConsole=debug
-
'';
-
systemd.extraConfig = ''
# Don't clobber the console with duplicate systemd messages.
ShowStatus=no
···
DefaultTimeoutStartSec=300
DefaultDeviceTimeoutSec=300
'';
-
-
boot.initrd.systemd.extraConfig = config.systemd.extraConfig;
boot.consoleLogLevel = 7;
+7
nixos/tests/systemd-initrd-modprobe.nix
···
name = "systemd-initrd-modprobe";
nodes.machine = { pkgs, ... }: {
+
testing.initrdBackdoor = true;
boot.initrd.systemd.enable = true;
boot.initrd.kernelModules = [ "loop" ]; # Load module in initrd.
boot.extraModprobeConfig = ''
···
};
testScript = ''
+
machine.wait_for_unit("initrd.target")
+
max_loop = machine.succeed("cat /sys/module/loop/parameters/max_loop")
+
assert int(max_loop) == 42, "Parameter should be respected for initrd kernel modules"
+
+
# Make sure it sticks in stage 2
+
machine.switch_root()
machine.wait_for_unit("multi-user.target")
max_loop = machine.succeed("cat /sys/module/loop/parameters/max_loop")
assert int(max_loop) == 42, "Parameter should be respected for initrd kernel modules"
+13 -39
nixos/tests/systemd-initrd-networkd-ssh.nix
···
nodes = {
server = { config, pkgs, ... }: {
-
environment.systemPackages = [ pkgs.cryptsetup ];
-
boot.loader.systemd-boot.enable = true;
-
boot.loader.timeout = 0;
-
virtualisation = {
-
emptyDiskImages = [ 4096 ];
-
useBootLoader = true;
-
# Booting off the encrypted disk requires an available init script from
-
# the Nix store
-
mountHostNixStore = true;
-
useEFIBoot = true;
-
};
-
-
specialisation.encrypted-root.configuration = {
-
virtualisation.rootDevice = "/dev/mapper/root";
-
virtualisation.fileSystems."/".autoFormat = true;
-
boot.initrd.luks.devices = lib.mkVMOverride {
-
root.device = "/dev/vdb";
-
};
-
boot.initrd.systemd.enable = true;
-
boot.initrd.network = {
+
testing.initrdBackdoor = true;
+
boot.initrd.systemd.enable = true;
+
boot.initrd.systemd.contents."/etc/msg".text = "foo";
+
boot.initrd.network = {
+
enable = true;
+
ssh = {
enable = true;
-
ssh = {
-
enable = true;
-
authorizedKeys = [ (lib.readFile ./initrd-network-ssh/id_ed25519.pub) ];
-
port = 22;
-
# Terrible hack so it works with useBootLoader
-
hostKeys = [ { outPath = "${./initrd-network-ssh/ssh_host_ed25519_key}"; } ];
-
};
+
authorizedKeys = [ (lib.readFile ./initrd-network-ssh/id_ed25519.pub) ];
+
port = 22;
+
hostKeys = [ ./initrd-network-ssh/ssh_host_ed25519_key ];
};
};
};
···
status, _ = client.execute("nc -z server 22")
return status == 0
-
server.wait_for_unit("multi-user.target")
-
server.succeed(
-
"echo somepass | cryptsetup luksFormat --type=luks2 /dev/vdb",
-
"bootctl set-default nixos-generation-1-specialisation-encrypted-root.conf",
-
"sync",
-
)
-
server.shutdown()
-
server.start()
-
client.wait_for_unit("network.target")
with client.nested("waiting for SSH server to come up"):
retry(ssh_is_up)
-
client.succeed(
-
"echo somepass | ssh -i /etc/sshKey -o UserKnownHostsFile=/etc/knownHosts server 'systemd-tty-ask-password-agent' & exit"
+
msg = client.succeed(
+
"ssh -i /etc/sshKey -o UserKnownHostsFile=/etc/knownHosts server 'cat /etc/msg'"
)
+
assert "foo" in msg
+
server.switch_root()
server.wait_for_unit("multi-user.target")
-
server.succeed("mount | grep '/dev/mapper/root on /'")
'';
})
+74 -56
nixos/tests/systemd-initrd-networkd.nix
···
-
import ./make-test-python.nix ({ pkgs, lib, ... }: {
-
name = "systemd-initrd-network";
-
meta.maintainers = [ lib.maintainers.elvishjerricco ];
+
{ system ? builtins.currentSystem
+
, config ? {}
+
, pkgs ? import ../.. { inherit system config; }
+
, lib ? pkgs.lib
+
}:
+
+
with import ../lib/testing-python.nix { inherit system pkgs; };
+
+
let
+
inherit (lib.maintainers) elvishjerricco;
+
+
common = {
+
boot.initrd.systemd = {
+
enable = true;
+
network.wait-online.timeout = 10;
+
network.wait-online.anyInterface = true;
+
targets.network-online.requiredBy = [ "initrd.target" ];
+
services.systemd-networkd-wait-online.requiredBy =
+
[ "network-online.target" ];
+
initrdBin = [ pkgs.iproute2 pkgs.iputils pkgs.gnugrep ];
+
};
+
testing.initrdBackdoor = true;
+
boot.initrd.network.enable = true;
+
};
+
+
mkFlushTest = flush: script: makeTest {
+
name = "systemd-initrd-network-${lib.optionalString (!flush) "no-"}flush";
+
meta.maintainers = [ elvishjerricco ];
+
+
nodes.machine = {
+
imports = [ common ];
-
nodes = let
-
mkFlushTest = flush: script: { ... }: {
-
boot.initrd.systemd.enable = true;
-
boot.initrd.network = {
-
enable = true;
-
flushBeforeStage2 = flush;
-
};
+
boot.initrd.network.flushBeforeStage2 = flush;
systemd.services.check-flush = {
requiredBy = ["multi-user.target"];
before = ["network-pre.target" "multi-user.target"];
···
inherit script;
};
};
-
in {
-
basic = { ... }: {
-
boot.initrd.network.enable = true;
-
boot.initrd.systemd = {
-
enable = true;
-
# Enable network-online to fail the test in case of timeout
-
network.wait-online.timeout = 10;
-
network.wait-online.anyInterface = true;
-
targets.network-online.requiredBy = [ "initrd.target" ];
-
services.systemd-networkd-wait-online.requiredBy =
-
[ "network-online.target" ];
-
-
initrdBin = [ pkgs.iproute2 pkgs.iputils pkgs.gnugrep ];
-
services.check = {
-
requiredBy = [ "initrd.target" ];
-
before = [ "initrd.target" ];
-
after = [ "network-online.target" ];
-
serviceConfig.Type = "oneshot";
-
path = [ pkgs.iproute2 pkgs.iputils pkgs.gnugrep ];
-
script = ''
-
ip addr | grep 10.0.2.15 || exit 1
-
ping -c1 10.0.2.2 || exit 1
-
'';
-
};
-
};
-
};
+
testScript = ''
+
machine.wait_for_unit("network-online.target")
+
machine.succeed(
+
"ip addr | grep 10.0.2.15",
+
"ping -c1 10.0.2.2",
+
)
+
machine.switch_root()
-
doFlush = mkFlushTest true ''
-
if ip addr | grep 10.0.2.15; then
-
echo "Network configuration survived switch-root; flushBeforeStage2 failed"
-
exit 1
-
fi
+
machine.wait_for_unit("multi-user.target")
'';
+
};
-
dontFlush = mkFlushTest false ''
-
if ! (ip addr | grep 10.0.2.15); then
-
echo "Network configuration didn't survive switch-root"
-
exit 1
-
fi
+
in {
+
basic = makeTest {
+
name = "systemd-initrd-network";
+
meta.maintainers = [ elvishjerricco ];
+
+
nodes.machine = common;
+
+
testScript = ''
+
machine.wait_for_unit("network-online.target")
+
machine.succeed(
+
"ip addr | grep 10.0.2.15",
+
"ping -c1 10.0.2.2",
+
)
+
machine.switch_root()
+
+
# Make sure the systemd-network user was set correctly in initrd
+
machine.wait_for_unit("multi-user.target")
+
machine.succeed("[ $(stat -c '%U,%G' /run/systemd/netif/links) = systemd-network,systemd-network ]")
+
machine.succeed("ip addr show >&2")
+
machine.succeed("ip route show >&2")
'';
};
-
testScript = ''
-
start_all()
-
basic.wait_for_unit("multi-user.target")
-
doFlush.wait_for_unit("multi-user.target")
-
dontFlush.wait_for_unit("multi-user.target")
-
# Make sure the systemd-network user was set correctly in initrd
-
basic.succeed("[ $(stat -c '%U,%G' /run/systemd/netif/links) = systemd-network,systemd-network ]")
-
basic.succeed("ip addr show >&2")
-
basic.succeed("ip route show >&2")
+
doFlush = mkFlushTest true ''
+
if ip addr | grep 10.0.2.15; then
+
echo "Network configuration survived switch-root; flushBeforeStage2 failed"
+
exit 1
+
fi
'';
-
})
+
+
dontFlush = mkFlushTest false ''
+
if ! (ip addr | grep 10.0.2.15); then
+
echo "Network configuration didn't survive switch-root"
+
exit 1
+
fi
+
'';
+
}
+8 -4
nixos/tests/systemd-initrd-simple.nix
···
name = "systemd-initrd-simple";
nodes.machine = { pkgs, ... }: {
-
boot.initrd.systemd = {
-
enable = true;
-
emergencyAccess = true;
-
};
+
testing.initrdBackdoor = true;
+
boot.initrd.systemd.enable = true;
virtualisation.fileSystems."/".autoResize = true;
};
testScript = ''
import subprocess
+
+
with subtest("testing initrd backdoor"):
+
machine.wait_for_unit("initrd.target")
+
machine.succeed("systemctl status initrd-fs.target")
+
machine.switch_root()
with subtest("handover to stage-2 systemd works"):
machine.wait_for_unit("multi-user.target")
···
subprocess.check_call(["qemu-img", "resize", "vm-state-machine/machine.qcow2", "+1G"])
machine.start()
+
machine.switch_root()
newAvail = machine.succeed("df --output=avail / | sed 1d")
assert int(oldAvail) < int(newAvail), "File system did not grow"