Merge pull request #254370 from jakubgs/mtr-exporter/multi-job

- `rome` was removed because it is no longer maintained and is succeeded by `biome`.

- The `services.mtr-exporter.target` has been removed in favor of `services.mtr-exporter.jobs` which allows specifying multiple targets.

## Other Notable Changes {#sec-release-23.11-notable-changes}

- The Cinnamon module now enables XDG desktop integration by default. If you are experiencing collisions related to xdg-desktop-portal-gtk you can safely remove `xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-gtk ];` from your NixOS configuration.

let

  inherit (lib)

    maintainers types mkEnableOption mkOption mkIf

    literalExpression escapeShellArg escapeShellArgs;

    maintainers types literalExpression

    escapeShellArg escapeShellArgs

    mkEnableOption mkOption mkRemovedOptionModule mkIf mdDoc

    optionalString concatMapStrings concatStringsSep;

  cfg = config.services.mtr-exporter;

  jobsConfig = pkgs.writeText "mtr-exporter.conf" (concatMapStrings (job: ''

    ${job.name} -- ${job.schedule} -- ${concatStringsSep " " job.flags} ${job.address}

  '') cfg.jobs);

in {

  imports = [

    (mkRemovedOptionModule [ "services" "mtr-exporter" "target" ] "Use services.mtr-exporter.jobs instead.")

    (mkRemovedOptionModule [ "services" "mtr-exporter" "mtrFlags" ] "Use services.mtr-exporter.jobs.<job>.flags instead.")

  ];

  options = {

    services = {

      mtr-exporter = {

        enable = mkEnableOption (lib.mdDoc "a Prometheus exporter for MTR");

        enable = mkEnableOption (mdDoc "a Prometheus exporter for MTR");

        target = mkOption {

        address = mkOption {

          type = types.str;

          example = "example.org";

          description = lib.mdDoc "Target to check using MTR.";

        };

        interval = mkOption {

          type = types.int;

          default = 60;

          description = lib.mdDoc "Interval between MTR checks in seconds.";

          default = "127.0.0.1";

          description = lib.mdDoc "Listen address for MTR exporter.";

        };

        port = mkOption {

          type = types.port;

          default = 8080;

          description = lib.mdDoc "Listen port for MTR exporter.";

          description = mdDoc "Listen port for MTR exporter.";

        };

        extraFlags = mkOption {

          type = types.listOf types.str;

          default = [];

          example = ["-flag.deprecatedMetrics"];

          description = mdDoc ''

            Extra command line options to pass to MTR exporter.

          '';

        };

        package = mkOption {

          type = types.package;

          default = pkgs.mtr-exporter;

          defaultText = literalExpression "pkgs.mtr-exporter";

          description = mdDoc "The MTR exporter package to use.";

        };

        mtrPackage = mkOption {

          type = types.package;

          default = pkgs.mtr;

          defaultText = literalExpression "pkgs.mtr";

          description = mdDoc "The MTR package to use.";

        };

        jobs = mkOption {

          description = mdDoc "List of MTR jobs. Will be added to /etc/mtr-exporter.conf";

          type = types.nonEmptyListOf (types.submodule {

            options = {

              name = mkOption {

                type = types.str;

                description = mdDoc "Name of ICMP pinging job.";

              };

              address = mkOption {

                type = types.str;

          default = "127.0.0.1";

          description = lib.mdDoc "Listen address for MTR exporter.";

                example = "host.example.org:1234";

                description = mdDoc "Target address for MTR client.";

              };

        mtrFlags = mkOption {

              schedule = mkOption {

                type = types.str;

                default = "@every 60s";

                example = "@hourly";

                description = mdDoc "Schedule of MTR checks. Also accepts Cron format.";

              };

              flags = mkOption {

                type = with types; listOf str;

                default = [];

                example = ["-G1"];

          description = lib.mdDoc "Additional flags to pass to MTR.";

                description = mdDoc "Additional flags to pass to MTR.";

              };

            };

          });

        };

      };

    };

  };

  config = mkIf cfg.enable {

    environment.etc."mtr-exporter.conf" = {

      source = jobsConfig;

    };

    systemd.services.mtr-exporter = {

      script = ''

        exec ${pkgs.mtr-exporter}/bin/mtr-exporter \

          -mtr ${pkgs.mtr}/bin/mtr \

          -schedule '@every ${toString cfg.interval}s' \

          -bind ${escapeShellArg cfg.address}:${toString cfg.port} \

          -- \

          ${escapeShellArgs (cfg.mtrFlags ++ [ cfg.target ])}

      '';

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

      requires = [ "network.target" ];

      after = [ "network.target" ];

      serviceConfig = {

        ExecStart = ''

          ${cfg.package}/bin/mtr-exporter \

            -mtr '${cfg.mtrPackage}/bin/mtr' \

            -bind ${escapeShellArg "${cfg.address}:${toString cfg.port}"} \

            -jobs '${jobsConfig}' \

            ${escapeShellArgs cfg.extraFlags}

        '';

        Restart = "on-failure";

        # Hardening

        CapabilityBoundingSet = [ "" ];