diff options
Diffstat (limited to 'nixos/modules/services/backup/snapraid.nix')
| -rw-r--r-- | nixos/modules/services/backup/snapraid.nix | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/nixos/modules/services/backup/snapraid.nix b/nixos/modules/services/backup/snapraid.nix new file mode 100644 index 000000000000..c9b2550e80e8 --- /dev/null +++ b/nixos/modules/services/backup/snapraid.nix @@ -0,0 +1,239 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let cfg = config.services.snapraid; +in +{ + imports = [ + # Should have never been on the top-level. + (mkRenamedOptionModule [ "snapraid" ] [ "services" "snapraid" ]) + ]; + + options.services.snapraid = with types; { + enable = mkEnableOption (lib.mdDoc "SnapRAID"); + dataDisks = mkOption { + default = { }; + example = { + d1 = "/mnt/disk1/"; + d2 = "/mnt/disk2/"; + d3 = "/mnt/disk3/"; + }; + description = lib.mdDoc "SnapRAID data disks."; + type = attrsOf str; + }; + parityFiles = mkOption { + default = [ ]; + example = [ + "/mnt/diskp/snapraid.parity" + "/mnt/diskq/snapraid.2-parity" + "/mnt/diskr/snapraid.3-parity" + "/mnt/disks/snapraid.4-parity" + "/mnt/diskt/snapraid.5-parity" + "/mnt/disku/snapraid.6-parity" + ]; + description = lib.mdDoc "SnapRAID parity files."; + type = listOf str; + }; + contentFiles = mkOption { + default = [ ]; + example = [ + "/var/snapraid.content" + "/mnt/disk1/snapraid.content" + "/mnt/disk2/snapraid.content" + ]; + description = lib.mdDoc "SnapRAID content list files."; + type = listOf str; + }; + exclude = mkOption { + default = [ ]; + example = [ "*.unrecoverable" "/tmp/" "/lost+found/" ]; + description = lib.mdDoc "SnapRAID exclude directives."; + type = listOf str; + }; + touchBeforeSync = mkOption { + default = true; + example = false; + description = lib.mdDoc + "Whether {command}`snapraid touch` should be run before {command}`snapraid sync`."; + type = bool; + }; + sync.interval = mkOption { + default = "01:00"; + example = "daily"; + description = lib.mdDoc "How often to run {command}`snapraid sync`."; + type = str; + }; + scrub = { + interval = mkOption { + default = "Mon *-*-* 02:00:00"; + example = "weekly"; + description = lib.mdDoc "How often to run {command}`snapraid scrub`."; + type = str; + }; + plan = mkOption { + default = 8; + example = 5; + description = lib.mdDoc + "Percent of the array that should be checked by {command}`snapraid scrub`."; + type = int; + }; + olderThan = mkOption { + default = 10; + example = 20; + description = lib.mdDoc + "Number of days since data was last scrubbed before it can be scrubbed again."; + type = int; + }; + }; + extraConfig = mkOption { + default = ""; + example = '' + nohidden + blocksize 256 + hashsize 16 + autosave 500 + pool /pool + ''; + description = lib.mdDoc "Extra config options for SnapRAID."; + type = lines; + }; + }; + + config = + let + nParity = builtins.length cfg.parityFiles; + mkPrepend = pre: s: pre + s; + in + mkIf cfg.enable { + assertions = [ + { + assertion = nParity <= 6; + message = "You can have no more than six SnapRAID parity files."; + } + { + assertion = builtins.length cfg.contentFiles >= nParity + 1; + message = + "There must be at least one SnapRAID content file for each SnapRAID parity file plus one."; + } + ]; + + environment = { + systemPackages = with pkgs; [ snapraid ]; + + etc."snapraid.conf" = { + text = with cfg; + let + prependData = mkPrepend "data "; + prependContent = mkPrepend "content "; + prependExclude = mkPrepend "exclude "; + in + concatStringsSep "\n" + (map prependData + ((mapAttrsToList (name: value: name + " " + value)) dataDisks) + ++ zipListsWith (a: b: a + b) + ([ "parity " ] ++ map (i: toString i + "-parity ") (range 2 6)) + parityFiles ++ map prependContent contentFiles + ++ map prependExclude exclude) + "\n" + extraConfig; + }; + }; + + systemd.services = with cfg; { + snapraid-scrub = { + description = "Scrub the SnapRAID array"; + startAt = scrub.interval; + serviceConfig = { + Type = "oneshot"; + ExecStart = "${pkgs.snapraid}/bin/snapraid scrub -p ${ + toString scrub.plan + } -o ${toString scrub.olderThan}"; + Nice = 19; + IOSchedulingPriority = 7; + CPUSchedulingPolicy = "batch"; + + LockPersonality = true; + MemoryDenyWriteExecute = true; + NoNewPrivileges = true; + PrivateDevices = true; + PrivateTmp = true; + ProtectClock = true; + ProtectControlGroups = true; + ProtectHostname = true; + ProtectKernelLogs = true; + ProtectKernelModules = true; + ProtectKernelTunables = true; + RestrictAddressFamilies = "none"; + RestrictNamespaces = true; + RestrictRealtime = true; + RestrictSUIDSGID = true; + SystemCallArchitectures = "native"; + SystemCallFilter = "@system-service"; + SystemCallErrorNumber = "EPERM"; + CapabilityBoundingSet = "CAP_DAC_OVERRIDE"; + + ProtectSystem = "strict"; + ProtectHome = "read-only"; + ReadWritePaths = + # scrub requires access to directories containing content files + # to remove them if they are stale + let + contentDirs = map dirOf contentFiles; + in + unique ( + attrValues dataDisks ++ contentDirs + ); + }; + unitConfig.After = "snapraid-sync.service"; + }; + snapraid-sync = { + description = "Synchronize the state of the SnapRAID array"; + startAt = sync.interval; + serviceConfig = { + Type = "oneshot"; + ExecStart = "${pkgs.snapraid}/bin/snapraid sync"; + Nice = 19; + IOSchedulingPriority = 7; + CPUSchedulingPolicy = "batch"; + + LockPersonality = true; + MemoryDenyWriteExecute = true; + NoNewPrivileges = true; + PrivateTmp = true; + ProtectClock = true; + ProtectControlGroups = true; + ProtectHostname = true; + ProtectKernelLogs = true; + ProtectKernelModules = true; + ProtectKernelTunables = true; + RestrictAddressFamilies = "none"; + RestrictNamespaces = true; + RestrictRealtime = true; + RestrictSUIDSGID = true; + SystemCallArchitectures = "native"; + SystemCallFilter = "@system-service"; + SystemCallErrorNumber = "EPERM"; + CapabilityBoundingSet = "CAP_DAC_OVERRIDE" + + lib.optionalString cfg.touchBeforeSync " CAP_FOWNER"; + + ProtectSystem = "strict"; + ProtectHome = "read-only"; + ReadWritePaths = + # sync requires access to directories containing content files + # to remove them if they are stale + let + contentDirs = map dirOf contentFiles; + # Multiple "split" parity files can be specified in a single + # "parityFile", separated by a comma. + # https://www.snapraid.it/manual#7.1 + splitParityFiles = map (s: splitString "," s) parityFiles; + in + unique ( + attrValues dataDisks ++ splitParityFiles ++ contentDirs + ); + } // optionalAttrs touchBeforeSync { + ExecStartPre = "${pkgs.snapraid}/bin/snapraid touch"; + }; + }; + }; + }; +} |