nginx for sub domain based reverse proxying to static resources

default.conf

server {
    listen 80;
    server_name ~^(?<subdomain>.+)\.(.*)$;
    root /usr/share/nginx/html/dist;

    location ~ ^.+\..+$ {
        try_files $uri @assets;
    }

    location / {
        try_files $uri $uri/ @rewrites;
    }

    location @rewrites {
        rewrite ^(.+)$ /index.html last;
    }

    location @assets {
        # note that this assumes you store your env specific files in dedicated folders named by their subdomain.
        rewrite ^/(.+)$ /cdn-path/$subdomain/$1 break;

        resolver 8.8.8.8;

        proxy_hide_header ETag;
        proxy_hide_header x-amz-id-2;
        proxy_hide_header x-amz-request-id;
        proxy_intercept_errors on;
        proxy_pass https://baseurl-of-cdn;
    }

    sendfile off;
}