nixpkgs/nixos/modules/services/backup/sanoid.nix

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{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.sanoid;
datasetSettingsType = with types;
(attrsOf (nullOr (oneOf [ str int bool (listOf str) ]))) // {
description = "dataset/template options";
};
# Default values from https://github.com/jimsalterjrs/sanoid/blob/master/sanoid.defaults.conf
commonOptions = {
hourly = mkOption {
description = "Number of hourly snapshots.";
type = types.ints.unsigned;
default = 48;
};
daily = mkOption {
description = "Number of daily snapshots.";
type = types.ints.unsigned;
default = 90;
};
monthly = mkOption {
description = "Number of monthly snapshots.";
type = types.ints.unsigned;
default = 6;
};
yearly = mkOption {
description = "Number of yearly snapshots.";
type = types.ints.unsigned;
default = 0;
};
autoprune = mkOption {
description = "Whether to automatically prune old snapshots.";
type = types.bool;
default = true;
};
autosnap = mkOption {
description = "Whether to automatically take snapshots.";
type = types.bool;
default = true;
};
settings = mkOption {
description = ''
Free-form settings for this template/dataset. See
<link xlink:href="https://github.com/jimsalterjrs/sanoid/blob/master/sanoid.defaults.conf"/>
for allowed values.
'';
type = datasetSettingsType;
};
};
commonConfig = config: {
settings = {
hourly = mkDefault config.hourly;
daily = mkDefault config.daily;
monthly = mkDefault config.monthly;
yearly = mkDefault config.yearly;
autoprune = mkDefault config.autoprune;
autosnap = mkDefault config.autosnap;
};
};
datasetOptions = {
useTemplate = mkOption {
description = "Names of the templates to use for this dataset.";
type = (types.listOf (types.enum (attrNames cfg.templates))) // {
description = "list of template names";
};
default = [];
};
recursive = mkOption {
description = "Whether to recursively snapshot dataset children.";
type = types.bool;
default = false;
};
processChildrenOnly = mkOption {
description = "Whether to only snapshot child datasets if recursing.";
type = types.bool;
default = false;
};
};
datasetConfig = config: {
settings = {
use_template = mkDefault config.useTemplate;
recursive = mkDefault config.recursive;
process_children_only = mkDefault config.processChildrenOnly;
};
};
# Extract pool names from configured datasets
pools = unique (map (d: head (builtins.match "([^/]+).*" d)) (attrNames cfg.datasets));
configFile = let
mkValueString = v:
if builtins.isList v then concatStringsSep "," v
else generators.mkValueStringDefault {} v;
mkKeyValue = k: v: if v == null then ""
else generators.mkKeyValueDefault { inherit mkValueString; } "=" k v;
in generators.toINI { inherit mkKeyValue; } cfg.settings;
configDir = pkgs.writeTextDir "sanoid.conf" configFile;
in {
# Interface
options.services.sanoid = {
enable = mkEnableOption "Sanoid ZFS snapshotting service";
interval = mkOption {
type = types.str;
default = "hourly";
example = "daily";
description = ''
Run sanoid at this interval. The default is to run hourly.
The format is described in
<citerefentry><refentrytitle>systemd.time</refentrytitle>
<manvolnum>7</manvolnum></citerefentry>.
'';
};
datasets = mkOption {
type = types.attrsOf (types.submodule ({ config, ... }: {
options = commonOptions // datasetOptions;
config = mkMerge [ (commonConfig config) (datasetConfig config) ];
}));
default = {};
description = "Datasets to snapshot.";
};
templates = mkOption {
type = types.attrsOf (types.submodule ({ config, ... }: {
options = commonOptions;
config = commonConfig config;
}));
default = {};
description = "Templates for datasets.";
};
settings = mkOption {
type = types.attrsOf datasetSettingsType;
description = ''
Free-form settings written directly to the config file. See
<link xlink:href="https://github.com/jimsalterjrs/sanoid/blob/master/sanoid.defaults.conf"/>
for allowed values.
'';
};
extraArgs = mkOption {
type = types.listOf types.str;
default = [];
example = [ "--verbose" "--readonly" "--debug" ];
description = ''
Extra arguments to pass to sanoid. See
<link xlink:href="https://github.com/jimsalterjrs/sanoid/#sanoid-command-line-options"/>
for allowed options.
'';
};
};
# Implementation
config = mkIf cfg.enable {
services.sanoid.settings = mkMerge [
(mapAttrs' (d: v: nameValuePair ("template_" + d) v.settings) cfg.templates)
(mapAttrs (d: v: v.settings) cfg.datasets)
];
systemd.services.sanoid = {
description = "Sanoid snapshot service";
serviceConfig = {
ExecStartPre = map (pool: lib.escapeShellArgs [
"+/run/booted-system/sw/bin/zfs" "allow"
"sanoid" "snapshot,mount,destroy" pool
]) pools;
ExecStart = lib.escapeShellArgs ([
"${pkgs.sanoid}/bin/sanoid"
"--cron"
"--configdir" configDir
] ++ cfg.extraArgs);
ExecStopPost = map (pool: lib.escapeShellArgs [
"+/run/booted-system/sw/bin/zfs" "unallow" "sanoid" pool
]) pools;
User = "sanoid";
Group = "sanoid";
DynamicUser = true;
RuntimeDirectory = "sanoid";
CacheDirectory = "sanoid";
};
# Prevents missing snapshots during DST changes
environment.TZ = "UTC";
after = [ "zfs.target" ];
startAt = cfg.interval;
};
};
meta.maintainers = with maintainers; [ lopsided98 ];
}