nixpkgs/nixos/modules/services/backup/mysql-backup.nix
Vlastimil Holer 09a6ce91d8
nixos/mysqlBackup: set service Type
fixes #158802

Sets the mysql backup systemd service type to "oneshot" to ensure the
service is marked as started after the backup script fully proceeds. This
allows to reliably depend on completing of this service by other services.
2022-02-18 18:35:55 +01:00

131 lines
2.9 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
inherit (pkgs) mariadb gzip;
cfg = config.services.mysqlBackup;
defaultUser = "mysqlbackup";
backupScript = ''
set -o pipefail
failed=""
${concatMapStringsSep "\n" backupDatabaseScript cfg.databases}
if [ -n "$failed" ]; then
echo "Backup of database(s) failed:$failed"
exit 1
fi
'';
backupDatabaseScript = db: ''
dest="${cfg.location}/${db}.gz"
if ${mariadb}/bin/mysqldump ${if cfg.singleTransaction then "--single-transaction" else ""} ${db} | ${gzip}/bin/gzip -c > $dest.tmp; then
mv $dest.tmp $dest
echo "Backed up to $dest"
else
echo "Failed to back up to $dest"
rm -f $dest.tmp
failed="$failed ${db}"
fi
'';
in
{
options = {
services.mysqlBackup = {
enable = mkEnableOption "MySQL backups";
calendar = mkOption {
type = types.str;
default = "01:15:00";
description = ''
Configured when to run the backup service systemd unit (DayOfWeek Year-Month-Day Hour:Minute:Second).
'';
};
user = mkOption {
type = types.str;
default = defaultUser;
description = ''
User to be used to perform backup.
'';
};
databases = mkOption {
default = [];
type = types.listOf types.str;
description = ''
List of database names to dump.
'';
};
location = mkOption {
type = types.path;
default = "/var/backup/mysql";
description = ''
Location to put the gzipped MySQL database dumps.
'';
};
singleTransaction = mkOption {
default = false;
type = types.bool;
description = ''
Whether to create database dump in a single transaction
'';
};
};
};
config = mkIf cfg.enable {
users.users = optionalAttrs (cfg.user == defaultUser) {
${defaultUser} = {
isSystemUser = true;
createHome = false;
home = cfg.location;
group = "nogroup";
};
};
services.mysql.ensureUsers = [{
name = cfg.user;
ensurePermissions = with lib;
let
privs = "SELECT, SHOW VIEW, TRIGGER, LOCK TABLES";
grant = db: nameValuePair "${db}.*" privs;
in
listToAttrs (map grant cfg.databases);
}];
systemd = {
timers.mysql-backup = {
description = "Mysql backup timer";
wantedBy = [ "timers.target" ];
timerConfig = {
OnCalendar = cfg.calendar;
AccuracySec = "5m";
Unit = "mysql-backup.service";
};
};
services.mysql-backup = {
description = "MySQL backup service";
enable = true;
serviceConfig = {
Type = "oneshot";
User = cfg.user;
};
script = backupScript;
};
tmpfiles.rules = [
"d ${cfg.location} 0700 ${cfg.user} - - -"
];
};
};
}