Allow access to only a specific user from a htpasswd file

[Leigh Dyer]

Hi,

I have a password file that contains several users, but for one 
particular page on my site, I want only one specific user from that file 
to be allowed access. Apache has a "Require user" directive for this, 
and I'm looking for an equivalent in nginx.

I've tried testing the value of $remote_user -- this is what I have at 
the moment:

location /foo {
         auth_basic "Foo";
         auth_basic_user_file "foo-htpasswd";

         if ($remote_user = "leigh") {
                 proxy_pass http://127.0.0.1:19000;
         }
}

This mostly works, but if you log in with an account other than "leigh" 
that's in the password file, the browser returns a 404 and no longer 
prompts for login details. I'd like to keep prompting the user for a 
login until they successfully log in with the "leigh" account.

Thanks
Leigh