Commit 809f9788 authored by Kira Bruneau's avatar Kira Bruneau Committed by Cabia Rangris
Browse files

nixos/klipper: preserve SAVE_CONFIG for nixos-managed config 

Klipper macros that use `SAVE_CONFIG` (eg. bed mesh calibration, PID
tuning, ...) don't currently work with a nixos-managed config.

This can be worked around by using `services.klipper.mutableConfig =
true`, but then you lose out on being able to configure klipper from
NixOS.

This changes the default behaviour so that:

1. The config is stored in `services.klipper.configDir` instead of `/etc`
2. The config is copied instead of symlinked (keeping a timestamped backup of the existing config)
3. The `SAVE_CONFIG` section from the backup is copied over into the new config
4. The backup is deleted if the final config is identical
parent 7093d690

nixos/modules/services/misc/klipper.nix

+34 −23
Original line number Diff line number Diff line
@@ -18,6 +18,13 @@ let 
  };

in

{

  imports = [

    (lib.mkRenamedOptionModule

      [ "services" "klipper" "mutableConfigFolder" ]

      [ "services" "klipper" "configDir" ]

    )

  ];



  ##### interface

  options = {

    services.klipper = {
@@ -52,23 +59,22 @@ in 
        default = false;

        example = true;

        description = ''

          Whether to copy the config to a mutable directory instead of using the one directly from the nix store.

          This will only copy the config if the file at `services.klipper.mutableConfigPath` doesn't exist.

          Whether to manage the config outside of NixOS.



          It will still be initialized with the defined NixOS config if the file doesn't already exist.

        '';

      };



      mutableConfigFolder = lib.mkOption {

      configDir = lib.mkOption {

        type = lib.types.path;

        default = "/var/lib/klipper";

        description = "Path to mutable Klipper config file.";

        description = "Path to Klipper config file.";

      };



      configFile = lib.mkOption {

        type = lib.types.nullOr lib.types.path;

        default = null;

        description = ''

          Path to default Klipper config.

        '';

        description = "Path to default Klipper config.";

      };



      octoprintIntegration = lib.mkOption {
@@ -162,11 +168,6 @@ in 
      }

    ];



    environment.etc = lib.mkIf (!cfg.mutableConfig) {

      "klipper.cfg".source =

        if cfg.settings != null then format.generate "klipper.cfg" cfg.settings else cfg.configFile;

    };



    services.klipper = lib.mkIf cfg.octoprintIntegration {

      user = config.services.octoprint.user;

      group = config.services.octoprint.group;
@@ -178,9 +179,7 @@ in 
          "--input-tty=${cfg.inputTTY}"

          + lib.optionalString (cfg.apiSocket != null) " --api-server=${cfg.apiSocket}"

          + lib.optionalString (cfg.logFile != null) " --logfile=${cfg.logFile}";

        printerConfigPath =

          if cfg.mutableConfig then cfg.mutableConfigFolder + "/printer.cfg" else "/etc/klipper.cfg";

        printerConfigFile =

        printerConfig =

          if cfg.settings != null then format.generate "klipper.cfg" cfg.settings else cfg.configFile;

      in

      {
@@ -188,19 +187,31 @@ in 
        wantedBy = [ "multi-user.target" ];

        after = [ "network.target" ];

        preStart = ''

          mkdir -p ${cfg.mutableConfigFolder}

          ${lib.optionalString (cfg.mutableConfig) ''

            [ -e ${printerConfigPath} ] || {

              cp ${printerConfigFile} ${printerConfigPath}

              chmod +w ${printerConfigPath}

          mkdir -p ${cfg.configDir}

          pushd ${cfg.configDir}

          if [ -e printer.cfg ]; then

            ${

              if cfg.mutableConfig then

                ":"

              else

                ''

                  # Backup existing config using the same date format klipper uses for SAVE_CONFIG

                  old_config="printer-$(date +"%Y%m%d_%H%M%S").cfg"

                  mv printer.cfg "$old_config"

                  # Preserve SAVE_CONFIG section from the existing config

                  cat ${printerConfig} <(printf "\n") <(sed -n '/#*# <---------------------- SAVE_CONFIG ---------------------->/,$p' "$old_config") > printer.cfg

                  ${pkgs.diffutils}/bin/cmp printer.cfg "$old_config" && rm "$old_config"

                ''

            }

          ''}

          mkdir -p ${cfg.mutableConfigFolder}/gcodes

          else

            cat ${printerConfig} > printer.cfg

          fi

          popd

        '';



        serviceConfig =

          {

            ExecStart = "${cfg.package}/bin/klippy ${klippyArgs} ${printerConfigPath}";

            ExecStart = "${cfg.package}/bin/klippy ${klippyArgs} ${cfg.configDir}/printer.cfg";

            RuntimeDirectory = "klipper";

            StateDirectory = "klipper";

            SupplementaryGroups = [ "dialout" ];