{ config, lib, pkgs, ... }: with lib; let # Type for a valid systemd unit option. Needed for correctly passing "timerConfig" to "systemd.timers" unitOption = (import ../../system/boot/systemd-unit-options.nix { inherit config lib; }).unitOption; in { options.services.restic.backups = mkOption { description = '' Periodic backups to create with Restic. ''; type = types.attrsOf (types.submodule ({ name, ... }: { options = { passwordFile = mkOption { type = types.str; description = '' Read the repository password from a file. ''; example = "/etc/nixos/restic-password"; }; s3CredentialsFile = mkOption { type = with types; nullOr str; default = null; description = '' file containing the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY for an S3-hosted repository, in the format of an EnvironmentFile as described by systemd.exec(5) ''; }; rcloneOptions = mkOption { type = with types; nullOr (attrsOf (oneOf [ str bool ])); default = null; description = '' Options to pass to rclone to control its behavior. See for available options. When specifying option names, strip the leading --. To set a flag such as --drive-use-trash, which does not take a value, set the value to the Boolean true. ''; example = { bwlimit = "10M"; drive-use-trash = "true"; }; }; rcloneConfig = mkOption { type = with types; nullOr (attrsOf (oneOf [ str bool ])); default = null; description = '' Configuration for the rclone remote being used for backup. See the remote's specific options under rclone's docs at . When specifying option names, use the "config" name specified in the docs. For example, to set --b2-hard-delete for a B2 remote, use hard_delete = true in the attribute set. Warning: Secrets set in here will be world-readable in the Nix store! Consider using the rcloneConfigFile option instead to specify secret values separately. Note that options set here will override those set in the config file. ''; example = { type = "b2"; account = "xxx"; key = "xxx"; hard_delete = true; }; }; rcloneConfigFile = mkOption { type = with types; nullOr path; default = null; description = '' Path to the file containing rclone configuration. This file must contain configuration for the remote specified in this backup set and also must be readable by root. Options set in rcloneConfig will override those set in this file. ''; }; repository = mkOption { type = types.str; description = '' repository to backup to. ''; example = "sftp:backup@192.168.1.100:/backups/${name}"; }; paths = mkOption { type = types.listOf types.str; default = []; description = '' Which paths to backup. ''; example = [ "/var/lib/postgresql" "/home/user/backup" ]; }; timerConfig = mkOption { type = types.attrsOf unitOption; default = { OnCalendar = "daily"; }; description = '' When to run the backup. See man systemd.timer for details. ''; example = { OnCalendar = "00:05"; RandomizedDelaySec = "5h"; }; }; user = mkOption { type = types.str; default = "root"; description = '' As which user the backup should run. ''; example = "postgresql"; }; extraBackupArgs = mkOption { type = types.listOf types.str; default = []; description = '' Extra arguments passed to restic backup. ''; example = [ "--exclude-file=/etc/nixos/restic-ignore" ]; }; extraOptions = mkOption { type = types.listOf types.str; default = []; description = '' Extra extended options to be passed to the restic --option flag. ''; example = [ "sftp.command='ssh backup@192.168.1.100 -i /home/user/.ssh/id_rsa -s sftp'" ]; }; initialize = mkOption { type = types.bool; default = false; description = '' Create the repository if it doesn't exist. ''; }; pruneOpts = mkOption { type = types.listOf types.str; default = []; description = '' A list of options (--keep-* et al.) for 'restic forget --prune', to automatically prune old snapshots. The 'forget' command is run *after* the 'backup' command, so keep that in mind when constructing the --keep-* options. ''; example = [ "--keep-daily 7" "--keep-weekly 5" "--keep-monthly 12" "--keep-yearly 75" ]; }; dynamicFilesFrom = mkOption { type = with types; nullOr str; default = null; description = '' A script that produces a list of files to back up. The results of this command are given to the '--files-from' option. ''; example = "find /home/matt/git -type d -name .git"; }; }; })); default = {}; example = { localbackup = { paths = [ "/home" ]; repository = "/mnt/backup-hdd"; passwordFile = "/etc/nixos/secrets/restic-password"; initialize = true; }; remotebackup = { paths = [ "/home" ]; repository = "sftp:backup@host:/backups/home"; passwordFile = "/etc/nixos/secrets/restic-password"; extraOptions = [ "sftp.command='ssh backup@host -i /etc/nixos/secrets/backup-private-key -s sftp'" ]; timerConfig = { OnCalendar = "00:05"; RandomizedDelaySec = "5h"; }; }; }; }; config = { systemd.services = mapAttrs' (name: backup: let extraOptions = concatMapStrings (arg: " -o ${arg}") backup.extraOptions; resticCmd = "${pkgs.restic}/bin/restic${extraOptions}"; filesFromTmpFile = "/run/restic-backups-${name}/includes"; backupPaths = if (backup.dynamicFilesFrom == null) then concatStringsSep " " backup.paths else "--files-from ${filesFromTmpFile}"; pruneCmd = optionals (builtins.length backup.pruneOpts > 0) [ ( resticCmd + " forget --prune " + (concatStringsSep " " backup.pruneOpts) ) ( resticCmd + " check" ) ]; # Helper functions for rclone remotes rcloneRemoteName = builtins.elemAt (splitString ":" backup.repository) 1; rcloneAttrToOpt = v: "RCLONE_" + toUpper (builtins.replaceStrings [ "-" ] [ "_" ] v); rcloneAttrToConf = v: "RCLONE_CONFIG_" + toUpper (rcloneRemoteName + "_" + v); toRcloneVal = v: if lib.isBool v then lib.boolToString v else v; in nameValuePair "restic-backups-${name}" ({ environment = { RESTIC_PASSWORD_FILE = backup.passwordFile; RESTIC_REPOSITORY = backup.repository; } // optionalAttrs (backup.rcloneOptions != null) (mapAttrs' (name: value: nameValuePair (rcloneAttrToOpt name) (toRcloneVal value) ) backup.rcloneOptions) // optionalAttrs (backup.rcloneConfigFile != null) { RCLONE_CONFIG = backup.rcloneConfigFile; } // optionalAttrs (backup.rcloneConfig != null) (mapAttrs' (name: value: nameValuePair (rcloneAttrToConf name) (toRcloneVal value) ) backup.rcloneConfig); path = [ pkgs.openssh ]; restartIfChanged = false; serviceConfig = { Type = "oneshot"; ExecStart = [ "${resticCmd} backup ${concatStringsSep " " backup.extraBackupArgs} ${backupPaths}" ] ++ pruneCmd; User = backup.user; RuntimeDirectory = "restic-backups-${name}"; } // optionalAttrs (backup.s3CredentialsFile != null) { EnvironmentFile = backup.s3CredentialsFile; }; } // optionalAttrs (backup.initialize || backup.dynamicFilesFrom != null) { preStart = '' ${optionalString (backup.initialize) '' ${resticCmd} snapshots || ${resticCmd} init ''} ${optionalString (backup.dynamicFilesFrom != null) '' ${pkgs.writeScript "dynamicFilesFromScript" backup.dynamicFilesFrom} > ${filesFromTmpFile} ''} ''; } // optionalAttrs (backup.dynamicFilesFrom != null) { postStart = '' rm ${filesFromTmpFile} ''; }) ) config.services.restic.backups; systemd.timers = mapAttrs' (name: backup: nameValuePair "restic-backups-${name}" { wantedBy = [ "timers.target" ]; timerConfig = backup.timerConfig; }) config.services.restic.backups; }; }