How to redirect to primary domain

Quite often I encounter such redirects in Nginx configuration:

server {
    listen 80;
    server_name www.example.org;
    rewrite ^(.*)$ $scheme://example.org$uri;
}

I see three problems with this approach. Let’s fix them one by one.

First, use of regular expressions for such a simple case is unwarranted. return seems good enough:

server {
    listen 80;
    server_name www.example.org;
    return 302 $scheme://example.org$uri;
}

Second, in such cases we usually want permanent redirect. The rewrite use as in first snippet (rewrite ^(.*)$ $scheme://example.org$uri;) generates 302 Found. Let’s generate 301 Moved Permanently:

server {
    listen 80;
    server_name www.example.org;
    return 301 $scheme://example.org$uri;
}

Finally, $uri is not necessarily original URI. For redirects it may be better to use “full original request URI (with arguments)”—$request_uri:

server {
    listen 80;
    server_name www.example.org;
    return 301 $scheme://example.org$request_uri;
}

For example, my static blog engine (that powers this site) generates configuration with permanent redirect and $request_uri as I recommend here.