nixos/smokeping: Add a PoC for using networking.fqdn

nixos/modules/services/networking/smokeping.nix

@@ -124,7 +124,8 @@ in
       };
       hostName = mkOption {
         type = types.str;
-        default = config.networking.hostName;
+        default = config.networking.fqdn;
+        defaultText = "\${config.networking.fqdn}";
         example = "somewhere.example.com";
         description = "DNS name for the urls generated in the cgi.";
       };
@@ -156,6 +157,7 @@ in
       ownerEmail = mkOption {
         type = types.str;
         default = "no-reply@${cfg.hostName}";
+        defaultText = "no-reply@\${hostName}";
         example = "no-reply@yourdomain.com";
         description = "Email contact for owner";
       };

nixos/tests/smokeping.nix

@@ -8,6 +8,7 @@ import ./make-test-python.nix ({ pkgs, ...} : {
     sm =
       { ... }:
       {
+        networking.domain = "example.com"; # FQDN: sm.example.com
         services.smokeping = {
           enable = true;
           port = 8081;