nixpkgs/nixos/modules/services/misc/snapper.nix
Ales Huzik 6e65b724be nixos/snapper: improve config example
In the default configuration we have timers for creating and deleting
snapper snapshots, and it looks like if we just create configs with
correct mountpoints we will get automatic snapshots (which either
used to be true, or seems to be only true on Archlinux according to
their wiki). In default snapper configuration TIMELINE_CREATE and
TIMELINE_CLEANUP are set to "no", so just providing configs won't
be enough for having automatic backups, which are the main usecase
for snapper. In other linux distributions you would use `snapper
create-config` to generate configs for partitions and you'd have a
chance to notice that TIMELINE_CREATE is set to no. Also, my guess is
that it might be set to no by default for safety reasons in regular distros,
so that the config won't be actioned upon until the user finishes
customizing it.
2021-01-17 19:13:35 +11:00

165 lines
4.2 KiB
Nix

{ config, pkgs, lib, ... }:
with lib;
let
cfg = config.services.snapper;
in
{
options.services.snapper = {
snapshotInterval = mkOption {
type = types.str;
default = "hourly";
description = ''
Snapshot interval.
The format is described in
<citerefentry><refentrytitle>systemd.time</refentrytitle>
<manvolnum>7</manvolnum></citerefentry>.
'';
};
cleanupInterval = mkOption {
type = types.str;
default = "1d";
description = ''
Cleanup interval.
The format is described in
<citerefentry><refentrytitle>systemd.time</refentrytitle>
<manvolnum>7</manvolnum></citerefentry>.
'';
};
filters = mkOption {
type = types.nullOr types.lines;
default = null;
description = ''
Global display difference filter. See man:snapper(8) for more details.
'';
};
configs = mkOption {
default = { };
example = literalExample {
home = {
subvolume = "/home";
extraConfig = ''
ALLOW_USERS="alice"
TIMELINE_CREATE=yes
TIMELINE_CLEANUP=yes
'';
};
};
description = ''
Subvolume configuration
'';
type = types.attrsOf (types.submodule {
options = {
subvolume = mkOption {
type = types.path;
description = ''
Path of the subvolume or mount point.
This path is a subvolume and has to contain a subvolume named
.snapshots.
See also man:snapper(8) section PERMISSIONS.
'';
};
fstype = mkOption {
type = types.enum [ "btrfs" ];
default = "btrfs";
description = ''
Filesystem type. Only btrfs is stable and tested.
'';
};
extraConfig = mkOption {
type = types.lines;
default = "";
description = ''
Additional configuration next to SUBVOLUME and FSTYPE.
See man:snapper-configs(5).
'';
};
};
});
};
};
config = mkIf (cfg.configs != {}) (let
documentation = [ "man:snapper(8)" "man:snapper-configs(5)" ];
in {
environment = {
systemPackages = [ pkgs.snapper ];
# Note: snapper/config-templates/default is only needed for create-config
# which is not the NixOS way to configure.
etc = {
"sysconfig/snapper".text = ''
SNAPPER_CONFIGS="${lib.concatStringsSep " " (builtins.attrNames cfg.configs)}"
'';
}
// (mapAttrs' (name: subvolume: nameValuePair "snapper/configs/${name}" ({
text = ''
${subvolume.extraConfig}
FSTYPE="${subvolume.fstype}"
SUBVOLUME="${subvolume.subvolume}"
'';
})) cfg.configs)
// (lib.optionalAttrs (cfg.filters != null) {
"snapper/filters/default.txt".text = cfg.filters;
});
};
services.dbus.packages = [ pkgs.snapper ];
systemd.services.snapperd = {
description = "DBus interface for snapper";
inherit documentation;
serviceConfig = {
Type = "dbus";
BusName = "org.opensuse.Snapper";
ExecStart = "${pkgs.snapper}/bin/snapperd";
};
};
systemd.services.snapper-timeline = {
description = "Timeline of Snapper Snapshots";
inherit documentation;
serviceConfig.ExecStart = "${pkgs.snapper}/lib/snapper/systemd-helper --timeline";
};
systemd.timers.snapper-timeline = {
description = "Timeline of Snapper Snapshots";
inherit documentation;
wantedBy = [ "basic.target" ];
timerConfig.OnCalendar = cfg.snapshotInterval;
};
systemd.services.snapper-cleanup = {
description = "Cleanup of Snapper Snapshots";
inherit documentation;
serviceConfig.ExecStart = "${pkgs.snapper}/lib/snapper/systemd-helper --cleanup";
};
systemd.timers.snapper-cleanup = {
description = "Cleanup of Snapper Snapshots";
inherit documentation;
wantedBy = [ "basic.target" ];
timerConfig.OnBootSec = "10m";
timerConfig.OnUnitActiveSec = cfg.cleanupInterval;
};
});
}