nixpkgs/nixos/modules/virtualisation/libvirtd.nix
Lizard a937dbedea nixos/libvirtd: utilize onShutdown option (#49480)
`services.virtualisation.libvirtd.onShutdown` was previously unused.
While suspending a domain on host shutdown is the default, this commit
makes it so domains can be shut down, also.
2018-10-31 00:01:00 +01:00

228 lines
7.0 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.virtualisation.libvirtd;
vswitch = config.virtualisation.vswitch;
configFile = pkgs.writeText "libvirtd.conf" ''
unix_sock_group = "libvirtd"
unix_sock_rw_perms = "0770"
auth_unix_ro = "none"
auth_unix_rw = "none"
${cfg.extraConfig}
'';
qemuConfigFile = pkgs.writeText "qemu.conf" ''
${optionalString cfg.qemuOvmf ''
nvram = ["/run/libvirt/nix-ovmf/OVMF_CODE.fd:/run/libvirt/nix-ovmf/OVMF_VARS.fd"]
''}
${optionalString (!cfg.qemuRunAsRoot) ''
user = "qemu-libvirtd"
group = "qemu-libvirtd"
''}
${cfg.qemuVerbatimConfig}
'';
in {
###### interface
options = {
virtualisation.libvirtd.enable = mkOption {
type = types.bool;
default = false;
description = ''
This option enables libvirtd, a daemon that manages
virtual machines. Users in the "libvirtd" group can interact with
the daemon (e.g. to start or stop VMs) using the
<command>virsh</command> command line tool, among others.
'';
};
virtualisation.libvirtd.qemuPackage = mkOption {
type = types.package;
default = pkgs.qemu;
description = ''
Qemu package to use with libvirt.
`pkgs.qemu` can emulate alien architectures (e.g. aarch64 on x86)
`pkgs.qemu_kvm` saves disk space allowing to emulate only host architectures.
'';
};
virtualisation.libvirtd.extraConfig = mkOption {
type = types.lines;
default = "";
description = ''
Extra contents appended to the libvirtd configuration file,
libvirtd.conf.
'';
};
virtualisation.libvirtd.qemuRunAsRoot = mkOption {
type = types.bool;
default = true;
description = ''
If true, libvirtd runs qemu as root.
If false, libvirtd runs qemu as unprivileged user qemu-libvirtd.
Changing this option to false may cause file permission issues
for existing guests. To fix these, manually change ownership
of affected files in /var/lib/libvirt/qemu to qemu-libvirtd.
'';
};
virtualisation.libvirtd.qemuVerbatimConfig = mkOption {
type = types.lines;
default = ''
namespaces = []
'';
description = ''
Contents written to the qemu configuration file, qemu.conf.
Make sure to include a proper namespace configuration when
supplying custom configuration.
'';
};
virtualisation.libvirtd.qemuOvmf = mkOption {
type = types.bool;
default = true;
description = ''
Allows libvirtd to take advantage of OVMF when creating new
QEMU VMs with UEFI boot.
'';
};
virtualisation.libvirtd.extraOptions = mkOption {
type = types.listOf types.str;
default = [ ];
example = [ "--verbose" ];
description = ''
Extra command line arguments passed to libvirtd on startup.
'';
};
virtualisation.libvirtd.onShutdown = mkOption {
type = types.enum ["shutdown" "suspend" ];
default = "suspend";
description = ''
When shutting down / restarting the host what method should
be used to gracefully halt the guests. Setting to "shutdown"
will cause an ACPI shutdown of each guest. "suspend" will
attempt to save the state of the guests ready to restore on boot.
'';
};
};
###### implementation
config = mkIf cfg.enable {
environment.systemPackages = with pkgs; [ libvirt libressl.nc cfg.qemuPackage ];
boot.kernelModules = [ "tun" ];
users.groups.libvirtd.gid = config.ids.gids.libvirtd;
# libvirtd runs qemu as this user and group by default
users.extraGroups.qemu-libvirtd.gid = config.ids.gids.qemu-libvirtd;
users.extraUsers.qemu-libvirtd = {
uid = config.ids.uids.qemu-libvirtd;
isNormalUser = false;
group = "qemu-libvirtd";
};
systemd.packages = [ pkgs.libvirt ];
systemd.services.libvirtd = {
description = "Libvirt Virtual Machine Management Daemon";
wantedBy = [ "multi-user.target" ];
after = [ "systemd-udev-settle.service" ]
++ optional vswitch.enable "vswitchd.service";
environment.LIBVIRTD_ARGS = ''--config "${configFile}" ${concatStringsSep " " cfg.extraOptions}'';
path = [ cfg.qemuPackage ] # libvirtd requires qemu-img to manage disk images
++ optional vswitch.enable vswitch.package;
preStart = ''
mkdir -p /var/log/libvirt/qemu -m 755
rm -f /var/run/libvirtd.pid
mkdir -p /var/lib/libvirt
mkdir -p /var/lib/libvirt/dnsmasq
chmod 755 /var/lib/libvirt
chmod 755 /var/lib/libvirt/dnsmasq
# Copy default libvirt network config .xml files to /var/lib
# Files modified by the user will not be overwritten
for i in $(cd ${pkgs.libvirt}/var/lib && echo \
libvirt/qemu/networks/*.xml libvirt/qemu/networks/autostart/*.xml \
libvirt/nwfilter/*.xml );
do
mkdir -p /var/lib/$(dirname $i) -m 755
cp -npd ${pkgs.libvirt}/var/lib/$i /var/lib/$i
done
# Copy generated qemu config to libvirt directory
cp -f ${qemuConfigFile} /var/lib/libvirt/qemu.conf
# stable (not GC'able as in /nix/store) paths for using in <emulator> section of xml configs
mkdir -p /run/libvirt/nix-emulators
for emulator in ${pkgs.libvirt}/libexec/libvirt_lxc ${cfg.qemuPackage}/bin/qemu-kvm ${cfg.qemuPackage}/bin/qemu-system-*; do
ln -s --force "$emulator" /run/libvirt/nix-emulators/
done
${optionalString cfg.qemuOvmf ''
mkdir -p /run/libvirt/nix-ovmf
ln -s --force ${pkgs.OVMF.fd}/FV/OVMF_CODE.fd /run/libvirt/nix-ovmf/
ln -s --force ${pkgs.OVMF.fd}/FV/OVMF_VARS.fd /run/libvirt/nix-ovmf/
''}
'';
serviceConfig = {
Type = "notify";
KillMode = "process"; # when stopping, leave the VMs alone
Restart = "no";
};
restartIfChanged = false;
};
systemd.services.libvirt-guests = {
wantedBy = [ "multi-user.target" ];
path = with pkgs; [ coreutils libvirt gawk ];
restartIfChanged = false;
environment.ON_SHUTDOWN = "${cfg.onShutdown}";
};
systemd.sockets.virtlogd = {
description = "Virtual machine log manager socket";
wantedBy = [ "sockets.target" ];
listenStreams = [ "/run/libvirt/virtlogd-sock" ];
};
systemd.services.virtlogd = {
description = "Virtual machine log manager";
serviceConfig.ExecStart = "@${pkgs.libvirt}/sbin/virtlogd virtlogd";
restartIfChanged = false;
};
systemd.sockets.virtlockd = {
description = "Virtual machine lock manager socket";
wantedBy = [ "sockets.target" ];
listenStreams = [ "/run/libvirt/virtlockd-sock" ];
};
systemd.services.virtlockd = {
description = "Virtual machine lock manager";
serviceConfig.ExecStart = "@${pkgs.libvirt}/sbin/virtlockd virtlockd";
restartIfChanged = false;
};
};
}