How to configure nginx to redirect all request from domain aliases to main domain?

I do have an nginx server which responds to several domains and I do want to redirect all request to the main domain.

Example: website responding for xxx xxx.example.com yyy.example.com $hostname for both http and https.

I want to configure the server in such way that all requests to the other domain names will be redirected to xxx.example.com.

I thinks something along these lines should work:

set $primary_domain "xxx.example.com";
if ($host != $primary_domain) {
    rewrite ^ $scheme://$primary_domain permanent;
}

Most efficient and clean way to do this is to configure two separate server{} blocks - one to do redirects, and another one (with canonical name) to actually handle requests.

Example configuration:

server {
    listen 80;
    listen 443 ssl;

    server_name xxx yyy.example.com $hostname;

    ssl_certificate ...
    ssl_certificate_key ...

    return 302 $scheme://xxx.example.com$request_uri;
}

server {
    listen 80;
    listen 443 ssl;

    server_name xxx.example.com;

    ssl_certificate ...
    ssl_certificate_key ...

    ...
}

Documentation:

• http://nginx.org/r/server_name
• http://nginx.org/r/return