default server with custom 404

[Robin Becker]

I see this question has been asked and answered many times, but I am unable to 
make it work.

On a server with multiple virtual hosts I wish to make a catchall which responds 
to everything with a 404 that reveals no information.

I am running nginx version: nginx/1.8.1 on ubuntu 14.04.

My catchall looks like this

server {
         listen 80 default_server;
         listen 443 ssl default_server;
         allow all;
         charset utf-8;
         error_page 404 /404.html;
         root /mypath/html/;
         location = /404.html {
                 root  /mypath/html/;
                 }
         location / {
                 return 404;
                 }
         }


if I make a fake /etc/hosts dns say dongo.bilbo.com and point at my server then

http://dongo.bilbo.com/404.html shows me the correct 404 page with no Nginx 
info, however, any other path eg http://dongo.bilbo.com always shows me the 
standard Nginx 404 page.

Is there a way to customize my error page for this case?


I would add that the following works well for my real sites

>     charset utf-8;
>     error_page 404 /404.html;
>     location /404.html {
>         root /mypath/html;
>         }

and there I do see the 404.html from /mypath/html when I visit missing pages.

Alternatively is there a way to override nginx's 404 page so it doesn't reveal 
the server.
-- 
Robin Becker