Nginx Wildcard SSL with Wordpress Multisite Subdomains

Question

I have a wildcard certificate that secures *.example.com and I need to strip out the canonical www for all requests made for subdomains, eg: www.subdomain1.example.com => subdomain1.example.com

I reviewed this question: https://stackoverflow.com/questions/11323735/nginx-remove-www-and-respond-to-both

But the first server block they suggest:

server {
  server_name www.example.com;
  return 301 $scheme://example.com$request_uri;
}

does not work for www.subdomain.example.com

How can I catch and return a scheme for www.*.example.com ?

I reviewed another question: https://serverfault.com/questions/249952/wildcard-vhosts-on-nginx in which they use regular expression to match the server name, but I'm not sure how to apply this to my situation.

Here is my current setup:

server {
    listen [::]:80 ipv6only=off;
    server_name example.com *.example.com;
    return 301 https://$host$request_uri;
}

server {

    # SSL configuration

    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;
    include snippets/ssl-example.com.conf;
    include snippets/ssl-params.conf;
    server_name example.com *.example.com;

    root /usr/share/nginx/webroot;
    index index.php index.html index.htm;

    rewrite /wp-admin$ $scheme://$host$uri/ permanent;

    #subdomain multi site with wp in 'wp' subdir
    if (!-e $request_filename) {
    # Redirect wp-* files/folders
    rewrite ^(/[^/]+)?(/wp-.*) /wp/$2 last;

    # Redirect other php files
    rewrite ^(/[^/]+)?(/.*\.php) /wp/$2 last;
    }

    ...(etc)
}

Answer 1

You can use regular expressions in the server_name directive, but wildcard names (e.g. *.example.com) take precedence. See this document for details.

For example:

server {
    listen [::]:80 ipv6only=off;
    server_name ~^(www\.)?(?<name>(.+\.)?example\.com)$;
    return 301 https://$name$request_uri;
}

server {
    listen 443 ssl;
    listen [::]:443 ssl;
    include snippets/ssl-example.com.conf;
    include snippets/ssl-params.conf;

    server_name ~^www\.(?<name>(.+\.)?example\.com)$;
    return 301 https://$name$request_uri;
}

server {
    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;
    include snippets/ssl-example.com.conf;
    include snippets/ssl-params.conf;

    ...
}

The first server block matches http requests to any subdomain, and redirects to the non-www variant using https.

The second server block matches https requests to subdomains which begin with www. and redirects to the non-www variant.

The third server block does not need a server_name directive (as it is the default server) and handles all https requests to the main domain and non-www subdomains.