nixpkgs/nixos/tests/qemu-vm-external-disk-image.nix
nikstur 62e95d095d nixos/qemu-vm: optionally disable overriding fileSystems
Allow the user to disable overriding the fileSystems option with
virtualisation.fileSystems by setting
`virtualisation.fileSystems = lib.mkForce { };`.

With this change you can use the qemu-vm module to boot from an external
image that was not produced by the qemu-vm module itself. The user can
now re-use the modularly set fileSystems option instead of having to
reproduce it in virtualisation.fileSystems.
2023-10-02 11:13:26 +02:00

73 lines
2.1 KiB
Nix

# Tests that you can boot from an external disk image with the qemu-vm module.
# "External" here means that the image was not produced within the qemu-vm
# module and relies on the fileSystems option also set outside the qemu-vm
# module. Most notably, this tests that you can stop the qemu-vm module from
# overriding fileSystems with virtualisation.fileSystems so you don't have to
# replicate the previously set fileSystems in virtualisation.fileSystems.
{ lib, ... }:
let
rootFslabel = "external";
rootFsDevice = "/dev/disk/by-label/${rootFslabel}";
externalModule = { config, lib, pkgs, ... }: {
boot.loader.systemd-boot.enable = true;
fileSystems = {
"/".device = rootFsDevice;
};
system.build.diskImage = import ../lib/make-disk-image.nix {
inherit config lib pkgs;
label = rootFslabel;
partitionTableType = "efi";
format = "qcow2";
bootSize = "32M";
additionalSpace = "0M";
copyChannel = false;
};
};
in
{
name = "qemu-vm-external-disk-image";
meta.maintainers = with lib.maintainers; [ nikstur ];
nodes.machine = { config, lib, pkgs, ... }: {
virtualisation.directBoot.enable = false;
virtualisation.mountHostNixStore = false;
virtualisation.useEFIBoot = true;
# This stops the qemu-vm module from overriding the fileSystems option
# with virtualisation.fileSystems.
virtualisation.fileSystems = lib.mkForce { };
imports = [ externalModule ];
};
testScript = { nodes, ... }: ''
import os
import subprocess
import tempfile
tmp_disk_image = tempfile.NamedTemporaryFile()
subprocess.run([
"${nodes.machine.virtualisation.qemu.package}/bin/qemu-img",
"create",
"-f",
"qcow2",
"-b",
"${nodes.machine.system.build.diskImage}/nixos.qcow2",
"-F",
"qcow2",
tmp_disk_image.name,
])
# Set NIX_DISK_IMAGE so that the qemu script finds the right disk image.
os.environ['NIX_DISK_IMAGE'] = tmp_disk_image.name
machine.succeed("findmnt --kernel --source ${rootFsDevice} --target /")
'';
}