nixos-mailserver/mail-server/borgbackup.nix

79 lines
3.2 KiB
Nix

# nixos-mailserver: a simple mail server
# Copyright (C) 2016-2018 Robin Raymond
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>
{ config, pkgs, lib, ... }:
let
cfg = config.mailserver.borgbackup;
methodFragment = lib.optional (cfg.compression.method != null) cfg.compression.method;
autoFragment =
if cfg.compression.auto && cfg.compression.method == null
then throw "compression.method must be set when using auto."
else lib.optional cfg.compression.auto "auto";
levelFragment =
if cfg.compression.level != null && cfg.compression.method == null
then throw "compression.method must be set when using compression.level."
else lib.optional (cfg.compression.level != null) (toString cfg.compression.level);
compressionFragment = lib.concatStringsSep "," (lib.flatten [autoFragment methodFragment levelFragment]);
compression = lib.optionalString (compressionFragment != "") "--compression ${compressionFragment}";
encryptionFragment = cfg.encryption.method;
passphraseFile = lib.escapeShellArg cfg.encryption.passphraseFile;
passphraseFragment = lib.optionalString (cfg.encryption.method != "none")
(if cfg.encryption.passphraseFile != null then ''env BORG_PASSPHRASE="$(cat ${passphraseFile})"''
else throw "passphraseFile must be set when using encryption.");
locations = lib.escapeShellArgs cfg.locations;
name = lib.escapeShellArg cfg.name;
repoLocation = lib.escapeShellArg cfg.repoLocation;
extraInitArgs = lib.escapeShellArgs cfg.extraArgumentsForInit;
extraCreateArgs = lib.escapeShellArgs cfg.extraArgumentsForCreate;
cmdPreexec = lib.optionalString (cfg.cmdPreexec != null) cfg.cmdPreexec;
cmdPostexec = lib.optionalString (cfg.cmdPostexec != null) cfg.cmdPostexec;
borgScript = ''
export BORG_REPO=${repoLocation}
${cmdPreexec}
${passphraseFragment} ${pkgs.borgbackup}/bin/borg init ${extraInitArgs} --encryption ${encryptionFragment} || true
${passphraseFragment} ${pkgs.borgbackup}/bin/borg create ${extraCreateArgs} ${compression} ::${name} ${locations}
${cmdPostexec}
'';
in {
config = lib.mkIf (config.mailserver.enable && cfg.enable) {
environment.systemPackages = with pkgs; [
borgbackup
];
systemd.services.borgbackup = {
description = "borgbackup";
unitConfig.Documentation = "man:borgbackup";
script = borgScript;
serviceConfig = {
User = cfg.user;
Group = cfg.group;
CPUSchedulingPolicy = "idle";
IOSchedulingClass = "idle";
ProtectSystem = "full";
};
startAt = cfg.startAt;
};
};
}