nixos/opentelemetry-collector: validate config

- The `open-webui` package's postgres support have been moved to optional dependencies to comply with upstream changes in 0.6.26.

- `prl-tools` has been moved out of `linuxPackages` because Parallels Guest Tools become driverless since 26.1.0.

- `services.opentelemetry-collector` has a new option `validateConfigFile` option that checks the configuration file during build. It is enabled by default if the configuration file is in the Nix store.

    mkOption

    types

    getExe

    isStorePath

    literalMD

    ;

  cfg = config.services.opentelemetry-collector;

  opentelemetry-collector = cfg.package;

  settingsFormat = pkgs.formats.yaml { };

  generatedConf =

    if cfg.configFile == null then

      settingsFormat.generate "config.yaml" cfg.settings

    else

      cfg.configFile;

  conf =

    if cfg.validateConfigFile then

      pkgs.runCommandLocal "config.yaml" { inherit generatedConf; } ''

        cp $generatedConf $out

        ${getExe opentelemetry-collector} validate --config=file:$out

      ''

    else

      generatedConf;

in

{

  options.services.opentelemetry-collector = {

        Specify a path to a configuration file that Opentelemetry Collector should use.

      '';

    };

    validateConfigFile = lib.mkEnableOption "Validate configuration file" // {

      defaultText = literalMD "`true` if `configFile` is a store path";

      default = isStorePath cfg.configFile;

    };

  };

  config = mkIf cfg.enable {

      description = "Opentelemetry Collector Service Daemon";

      wantedBy = [ "multi-user.target" ];

      serviceConfig =

        let

          conf =

            if cfg.configFile == null then

              settingsFormat.generate "config.yaml" cfg.settings

            else

              cfg.configFile;

        in

        {

      serviceConfig = {

        ExecStart = "${getExe opentelemetry-collector} --config=file:${conf}";

        DynamicUser = true;

        Restart = "always";