cntlm service: cleanup non working config options (#26578)

- extraConfig was not working
- add possibility to add cntlm.conf in verbatime form
- create cntlm user as system user
- add no proxy option

nixos/modules/services/networking/cntlm.nix

@@ -5,15 +5,33 @@ with lib;
 let
 
   cfg = config.services.cntlm;
-  uid = config.ids.uids.cntlm;
+
+  configFile = if cfg.configText != "" then
+    pkgs.writeText "cntlm.conf" ''
+      ${cfg.configText}
+    ''
+    else
+    pkgs.writeText "lighttpd.conf" ''
+      # Cntlm Authentication Proxy Configuration
+      Username ${cfg.username}
+      Domain ${cfg.domain}
+      Password ${cfg.password}
+      ${optionalString (cfg.netbios_hostname != "") "Workstation ${cfg.netbios_hostname}"}
+      ${concatMapStrings (entry: "Proxy ${entry}\n") cfg.proxy}
+      ${optionalString (cfg.noproxy != []) "NoProxy ${concatStringsSep ", " cfg.noproxy}"}
+
+      ${concatMapStrings (port: ''
+        Listen ${toString port}
+      '') cfg.port}
+
+      ${cfg.extraConfig}
+    '';
 
 in
 
 {
 
-  options = {
-
-    services.cntlm = {
+  options.services.cntlm = {
 
     enable = mkOption {
       default = false;
@@ -40,6 +58,7 @@ in
 
     netbios_hostname = mkOption {
       type = types.str;
+      default = "";
       description = ''
         The hostname of your machine.
       '';
@@ -53,6 +72,15 @@ in
         number  of  proxies.  Should  one proxy fail, cntlm automatically moves on to the next one. The connect request fails only if the whole
         list of proxies is scanned and (for each request) and found to be invalid. Command-line takes precedence over the configuration file.
       '';
+      example = [ "proxy.example.com:81" ];
+    };
+
+    noproxy = mkOption {
+      description = ''
+        A list of domains where the proxy is skipped.
+      '';
+      default = [];
+      example = [ "*.example.com" "example.com" ];
     };
 
     port = mkOption {
@@ -61,6 +89,12 @@ in
     };
 
     extraConfig = mkOption {
+      type = types.lines;
+      default = "";
+      description = "Additional config appended to the end of the generated <filename>cntlm.conf</filename>.";
+    };
+
+    configText = mkOption {
        type = types.lines;
        default = "";
        description = "Verbatim contents of <filename>cntlm.conf</filename>.";
@@ -68,47 +102,25 @@ in
 
   };
 
-  };
-
-
   ###### implementation
 
-  config = mkIf config.services.cntlm.enable {
+  config = mkIf cfg.enable {
     systemd.services.cntlm = {
       description = "CNTLM is an NTLM / NTLM Session Response / NTLMv2 authenticating HTTP proxy";
       after = [ "network.target" ];
       wantedBy = [ "multi-user.target" ];
       serviceConfig = {
-        Type = "forking";
         User = "cntlm";
         ExecStart = ''
-          ${pkgs.cntlm}/bin/cntlm -U cntlm \
-            -c ${pkgs.writeText "cntlm_config" cfg.extraConfig}
+          ${pkgs.cntlm}/bin/cntlm -U cntlm -c ${configFile} -v -f
         '';
       };
     };
 
-    services.cntlm.netbios_hostname = mkDefault config.networking.hostName;
-  
     users.extraUsers.cntlm = {
       name = "cntlm";
       description = "cntlm system-wide daemon";
-      home = "/var/empty";
+      isSystemUser = true;
     };
-
-    services.cntlm.extraConfig =
-      ''
-        # Cntlm Authentication Proxy Configuration
-        Username        ${cfg.username}
-        Domain          ${cfg.domain}
-        Password        ${cfg.password}
-        Workstation     ${cfg.netbios_hostname}
-        ${concatMapStrings (entry: "Proxy ${entry}\n") cfg.proxy}
-    
-        ${concatMapStrings (port: ''
-          Listen ${toString port}
-        '') cfg.port}
-      '';      
   };
-  
 }