nixos/traefik: use formats.toml to generate config

nixos/modules/services/web-servers/traefik.nix

@@ -1,57 +1,15 @@
 { config, lib, pkgs, ... }:
 
-with lib;
-
 let
+  inherit (lib) mkDefault mkEnableOption mkIf mkOption mkPackageOption literalExpression types;
+
   cfg = config.services.traefik;
-  jsonValue = with types;
-    let
-      valueType = nullOr (oneOf [
-        bool
-        int
-        float
-        str
-        (lazyAttrsOf valueType)
-        (listOf valueType)
-      ]) // {
-        description = "JSON value";
-        emptyValue.value = { };
-      };
-    in valueType;
-  dynamicConfigFile = if cfg.dynamicConfigFile == null then
-    pkgs.runCommand "config.toml" {
-      buildInputs = [ pkgs.remarshal ];
-      preferLocalBuild = true;
-    } ''
-      remarshal -if json -of toml \
-        < ${
-          pkgs.writeText "dynamic_config.json"
-          (builtins.toJSON cfg.dynamicConfigOptions)
-        } \
-        > $out
-    ''
-  else
-    cfg.dynamicConfigFile;
-  staticConfigFile = if cfg.staticConfigFile == null then
-    pkgs.runCommand "config.toml" {
-      buildInputs = [ pkgs.yj ];
-      preferLocalBuild = true;
-    } ''
-      yj -jt -i \
-        < ${
-          pkgs.writeText "static_config.json" (builtins.toJSON
-            (recursiveUpdate cfg.staticConfigOptions {
-              providers.file.filename = "${dynamicConfigFile}";
-            }))
-        } \
-        > $out
-    ''
-  else
-    cfg.staticConfigFile;
+
+  configFormat = pkgs.formats.toml {};
 
   finalStaticConfigFile =
     if cfg.environmentFiles == []
-    then staticConfigFile
+    then cfg.staticConfigFile
     else "/run/traefik/config.toml";
 in {
   options.services.traefik = {
@@ -71,7 +29,7 @@ in {
       description = lib.mdDoc ''
         Static configuration for Traefik.
       '';
-      type = jsonValue;
+      type = configFormat.type;
       default = { entryPoints.http.address = ":80"; };
       example = {
         entryPoints.web.address = ":8080";
@@ -95,7 +53,7 @@ in {
       description = lib.mdDoc ''
         Dynamic configuration for Traefik.
       '';
-      type = jsonValue;
+      type = configFormat.type;
       default = { };
       example = {
         http.routers.router1 = {
@@ -140,6 +98,13 @@ in {
   };
 
   config = mkIf cfg.enable {
+    services.traefik = {
+      staticConfigOptions.providers.file.filename = cfg.dynamicConfigFile;
+
+      staticConfigFile = mkDefault (configFormat.generate "traefik-static.toml" cfg.staticConfigOptions);
+      dynamicConfigFile = mkDefault (configFormat.generate "traefik-dynamic.toml" cfg.dynamicConfigOptions);
+    };
+
     systemd.tmpfiles.rules = [ "d '${cfg.dataDir}' 0700 traefik traefik - -" ];
 
     systemd.services.traefik = {
@@ -154,7 +119,7 @@ in {
         ExecStartPre = lib.optional (cfg.environmentFiles != [])
           (pkgs.writeShellScript "pre-start" ''
             umask 077
-            ${pkgs.envsubst}/bin/envsubst -i "${staticConfigFile}" > "${finalStaticConfigFile}"
+            ${pkgs.envsubst}/bin/envsubst -i "${cfg.staticConfigFile}" > "${finalStaticConfigFile}"
           '');
         ExecStart = "${cfg.package}/bin/traefik --configfile=${finalStaticConfigFile}";
         Type = "simple";
@@ -184,4 +149,6 @@ in {
 
     users.groups.traefik = { };
   };
+
+  meta.maintainers = with lib.maintainers; [ Scrumplex ];
 }