backup-helper/backup.nix

76 lines
2.1 KiB
Nix

{ lib, config, pkgs, ... }:
let
cfg = config.backup-helper;
restic-wrapper = pkgs.writeShellApplication {
name = "restic-wrapper";
runtimeInputs = [
pkgs.restic
pkgs.systemd
];
text = ''
if [ "$#" -ne 1 ]; then
echo "Need exactly one argument, the path to backup.";
exit 1;
fi
echo "Starting backup.";
path="$(systemd-escape -u --path "$1")";
restic backup "$path";
'';
};
in
{
options.backup-helper.enable = lib.mkEnableOption "Enable backup-helper";
options.backup-helper = {
restic-repository = lib.mkOption {
type = lib.types.str;
default = "rest:http://10.69.12.52:8000/backup-nix";
description = "Repository to use for restic backup.";
};
backup-dirs = lib.mkOption {
type = lib.types.listOf lib.types.str;
default = [ ];
description = "Directories to be backed up.";
};
schedule = lib.mkOption {
type = lib.types.str;
default = "*-*-* 00:00:00";
description = "Schedule for backups. Needs to be valid systemd OnCalendar value.";
};
password-file = lib.mkOption {
type = lib.types.nullOr lib.types.str;
default = null;
description = "File containing the restic password.";
};
randomized-delay = lib.mkOption {
type = lib.types.int;
default = 0;
description = "Randomized delay in seconds to spread out backups.";
};
};
config = lib.mkIf cfg.enable {
systemd.services."backup-helper@" = {
after = [ "network-online.target" ];
environment = {
RESTIC_REPOSITORY = cfg.restic-repository;
} // lib.attrsets.optionalAttrs (builtins.hasAttr "password-file" cfg) {
RESTIC_PASSWORD_FILE = cfg.password-file;
};
serviceConfig = {
Type = "oneshot";
ExecStart = "${restic-wrapper}/bin/restic-wrapper %i";
};
};
systemd.timers."backup-helper@" = {
timerConfig = {
OnCalendar = cfg.schedule;
Persistent = true;
RandomizedDelaySec = cfg.randomized-delay;
};
};
systemd.units."backup-helper@etc-machine\x2did.timer" = {
enable = true;
};
};
}