depot/nixos/modules/virtualisation/lxd.nix
Luke Granger-Brown 57725ef3ec Squashed 'third_party/nixpkgs/' content from commit 76612b17c0ce
git-subtree-dir: third_party/nixpkgs
git-subtree-split: 76612b17c0ce71689921ca12d9ffdc9c23ce40b2
2024-11-10 23:59:47 +00:00

257 lines
8 KiB
Nix

# Systemd services for lxd.
{ config, lib, pkgs, ... }:
let
cfg = config.virtualisation.lxd;
preseedFormat = pkgs.formats.yaml {};
in {
imports = [
(lib.mkRemovedOptionModule [ "virtualisation" "lxd" "zfsPackage" ] "Override zfs in an overlay instead to override it globally")
];
options = {
virtualisation.lxd = {
enable = lib.mkOption {
type = lib.types.bool;
default = false;
description = ''
This option enables lxd, a daemon that manages
containers. Users in the "lxd" group can interact with
the daemon (e.g. to start or stop containers) using the
{command}`lxc` command line tool, among others.
Most of the time, you'll also want to start lxcfs, so
that containers can "see" the limits:
```
virtualisation.lxc.lxcfs.enable = true;
```
'';
};
package = lib.mkPackageOption pkgs "lxd-lts" { };
lxcPackage = lib.mkOption {
type = lib.types.package;
default = config.virtualisation.lxc.package;
defaultText = lib.literalExpression "config.virtualisation.lxc.package";
description = "The lxc package to use.";
};
zfsSupport = lib.mkOption {
type = lib.types.bool;
default = config.boot.zfs.enabled;
defaultText = lib.literalExpression "config.boot.zfs.enabled";
description = ''
Enables lxd to use zfs as a storage for containers.
This option is enabled by default if a zfs pool is configured
with nixos.
'';
};
recommendedSysctlSettings = lib.mkOption {
type = lib.types.bool;
default = false;
description = ''
Enables various settings to avoid common pitfalls when
running containers requiring many file operations.
Fixes errors like "Too many open files" or
"neighbour: ndisc_cache: neighbor table overflow!".
See https://lxd.readthedocs.io/en/latest/production-setup/
for details.
'';
};
preseed = lib.mkOption {
type = lib.types.nullOr (lib.types.submodule {
freeformType = preseedFormat.type;
});
default = null;
description = ''
Configuration for LXD preseed, see
<https://documentation.ubuntu.com/lxd/en/latest/howto/initialize/#initialize-preseed>
for supported values.
Changes to this will be re-applied to LXD which will overwrite existing entities or create missing ones,
but entities will *not* be removed by preseed.
'';
example = lib.literalExpression ''
{
networks = [
{
name = "lxdbr0";
type = "bridge";
config = {
"ipv4.address" = "10.0.100.1/24";
"ipv4.nat" = "true";
};
}
];
profiles = [
{
name = "default";
devices = {
eth0 = {
name = "eth0";
network = "lxdbr0";
type = "nic";
};
root = {
path = "/";
pool = "default";
size = "35GiB";
type = "disk";
};
};
}
];
storage_pools = [
{
name = "default";
driver = "dir";
config = {
source = "/var/lib/lxd/storage-pools/default";
};
}
];
}
'';
};
startTimeout = lib.mkOption {
type = lib.types.int;
default = 600;
apply = toString;
description = ''
Time to wait (in seconds) for LXD to become ready to process requests.
If LXD does not reply within the configured time, lxd.service will be
considered failed and systemd will attempt to restart it.
'';
};
ui = {
enable = lib.mkEnableOption "(experimental) LXD UI";
package = lib.mkPackageOption pkgs [ "lxd-ui" ] { };
};
};
};
###### implementation
config = lib.mkIf cfg.enable {
environment.systemPackages = [ cfg.package ];
# Note: the following options are also declared in virtualisation.lxc, but
# the latter can't be simply enabled to reuse the formers, because it
# does a bunch of unrelated things.
systemd.tmpfiles.rules = [ "d /var/lib/lxc/rootfs 0755 root root -" ];
security.apparmor = {
packages = [ cfg.lxcPackage ];
policies = {
"bin.lxc-start".profile = ''
include ${cfg.lxcPackage}/etc/apparmor.d/usr.bin.lxc-start
'';
"lxc-containers".profile = ''
include ${cfg.lxcPackage}/etc/apparmor.d/lxc-containers
'';
};
};
systemd.sockets.lxd = {
description = "LXD UNIX socket";
wantedBy = [ "sockets.target" ];
socketConfig = {
ListenStream = "/var/lib/lxd/unix.socket";
SocketMode = "0660";
SocketGroup = "lxd";
Service = "lxd.service";
};
};
systemd.services.lxd = {
description = "LXD Container Management Daemon";
wantedBy = [ "multi-user.target" ];
after = [
"network-online.target"
(lib.mkIf config.virtualisation.lxc.lxcfs.enable "lxcfs.service")
];
requires = [
"network-online.target"
"lxd.socket"
(lib.mkIf config.virtualisation.lxc.lxcfs.enable "lxcfs.service")
];
documentation = [ "man:lxd(1)" ];
path = [ pkgs.util-linux ]
++ lib.optional cfg.zfsSupport config.boot.zfs.package;
environment = lib.mkIf (cfg.ui.enable) {
"LXD_UI" = cfg.ui.package;
};
serviceConfig = {
ExecStart = "@${cfg.package}/bin/lxd lxd --group lxd";
ExecStartPost = "${cfg.package}/bin/lxd waitready --timeout=${cfg.startTimeout}";
ExecStop = "${cfg.package}/bin/lxd shutdown";
KillMode = "process"; # when stopping, leave the containers alone
LimitMEMLOCK = "infinity";
LimitNOFILE = "1048576";
LimitNPROC = "infinity";
TasksMax = "infinity";
Delegate = true; # LXD needs to manage cgroups in its subtree
# By default, `lxd` loads configuration files from hard-coded
# `/usr/share/lxc/config` - since this is a no-go for us, we have to
# explicitly tell it where the actual configuration files are
Environment = lib.mkIf (config.virtualisation.lxc.lxcfs.enable)
"LXD_LXC_TEMPLATE_CONFIG=${pkgs.lxcfs}/share/lxc/config";
};
unitConfig.ConditionPathExists = "!/var/lib/incus/.migrated-from-lxd";
};
systemd.services.lxd-preseed = lib.mkIf (cfg.preseed != null) {
description = "LXD initialization with preseed file";
wantedBy = ["multi-user.target"];
requires = ["lxd.service"];
after = ["lxd.service"];
script = ''
${pkgs.coreutils}/bin/cat ${preseedFormat.generate "lxd-preseed.yaml" cfg.preseed} | ${cfg.package}/bin/lxd init --preseed
'';
serviceConfig = {
Type = "oneshot";
};
};
users.groups.lxd = {};
users.users.root = {
subUidRanges = [ { startUid = 1000000; count = 65536; } ];
subGidRanges = [ { startGid = 1000000; count = 65536; } ];
};
boot.kernel.sysctl = lib.mkIf cfg.recommendedSysctlSettings {
"fs.inotify.max_queued_events" = 1048576;
"fs.inotify.max_user_instances" = 1048576;
"fs.inotify.max_user_watches" = 1048576;
"vm.max_map_count" = 262144; # TODO: Default vm.max_map_count has been increased system-wide
"kernel.dmesg_restrict" = 1;
"net.ipv4.neigh.default.gc_thresh3" = 8192;
"net.ipv6.neigh.default.gc_thresh3" = 8192;
"kernel.keys.maxkeys" = 2000;
};
boot.kernelModules = [ "veth" "xt_comment" "xt_CHECKSUM" "xt_MASQUERADE" "vhost_vsock" ]
++ lib.optionals (!config.networking.nftables.enable) [ "iptable_mangle" ];
};
}