add frontend redirect hosts

README.md

@@ -417,7 +417,10 @@ Example host configuration:
                     config.sops.secrets."borg-private-key".path;
                 };
 
-                frontend.hostName = "rabbigerzi.com";
+                frontend = {
+                  hostName = "rabbigerzi.com";
+                  redirectHostNames = [ "www.rabbigerzi.com" ];
+                };
 
                 backend = {
                   hostName = "api.rabbigerzi.com";

nix/nixos-module.nix

@@ -120,6 +120,12 @@ in
         description = "Frontend nginx virtual host name.";
       };
 
+      redirectHostNames = lib.mkOption {
+        type = lib.types.listOf lib.types.str;
+        default = [ ];
+        description = "Frontend host names that redirect to the canonical host.";
+      };
+
       publicUrl = lib.mkOption {
         type = lib.types.str;
         default = "https://${cfg.frontend.hostName}";
@@ -403,7 +409,13 @@ in
       recommendedProxySettings = lib.mkDefault true;
       recommendedTlsSettings = lib.mkDefault true;
 
-      virtualHosts = {
+      virtualHosts =
+        lib.genAttrs cfg.frontend.redirectHostNames (redirectHostName: {
+          enableACME = true;
+          forceSSL = true;
+          globalRedirect = cfg.frontend.hostName;
+        })
+        // {
           ${cfg.frontend.hostName} = lib.mkMerge [
             cfg.frontend.nginx
             {