<Nginx> How to setup Multi dynamic virtual hosts + www + subdomain

Question

There are some questions about nginx virtual hosts and subdomain configuration, but it can't achieve.

I hava 3 domain and an IP address(Multi-Site)

www.a1.com
www.a2.com
www.a3.com

I want to use a easy nginx configuration to set up it, and when I enter

URL Rewrites

a1.com      => force redirect non-www to WWW url www.a1.com

www.a1.com      => pass to /usr/share/nginx/html/a1.com/
www.blog.a1.com => pass to /usr/share/nginx/html/a1.com/blog/
*www.photo*.a1.com=> pass to /usr/share/nginx/html/a1.com/*photo*/
...and so on

a2.com      => force redirect non-www to WWW url www.a2.com

www.a2.com      => pass to /usr/share/nginx/html/a2.com/
www.blog.a2.com => pass to /usr/share/nginx/html/a2.com/blog/
www.photo.a2.com=> pass to /usr/share/nginx/html/a2.com/photo/
www.user.a2.com=> pass to /usr/share/nginx/html/a2.com/user/
...and so on

a1, a2 and a3.com are using the same configuration.

This is my first code, how can i fix it?

pseudo code

if subdomain lacks 'www' then pass to $scheme://www.$host$request_uri;
if subdmain <>'' then pass to /usr/share/nginx/html/$host/<#subdmain#>/$request_uri;

/etc/nginx/conf.d/default.conf

server {
    # Redirect non-www to WWW
    server_name "~^(?!www\.).*" ;
    return 301 $scheme://www.$host$request_uri;
}

server {

    listen 80 default;

    #automatic judging hostname
    server_name  ~^(www\.)?(?<domain>.+)$;

    location / {

        #automatic change folder
        root    /usr/share/nginx/html/$domain/;

        index index.html index.php;
        #try_files $uri $uri/ /index.php?$query_string;
    }

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000

    location ~ \.php$ {
        fastcgi_pass   127.0.0.1:9000;
        fastcgi_index  index.php;

        # judging subdomain which have "www"
        if ($subdomain = 'www') {
            fastcgi_param SCRIPT_FILENAME /usr/share/nginx/html/$domain$fastcgi_script_name;
        }
        # judging subdomain like "blog" and trans to blog folder
        else {
            fastcgi_param SCRIPT_FILENAME /usr/share/nginx/html/$domain/$subdomain/$fastcgi_script_name;
        }
        include    fastcgi_params;
    }
}

Answer 1

Dont overcomplexify nginx configs :) I suppose you can create 3 server {} blocks. 1st as you have now. 2nd for www.domain.com, and 3rd for www.subdomain.domain.com

For 2nd server definition you need this regexp:

server_name ~^(www\.)(?P<domain>.+)\.com$;
root /usr/share/nginx/html/$domain.com/www;

For 3rd server definition you need this regexp:

server_name ~^(www\.)(?P<subdomain>.+)\.(?P<domain>.+)\.com$;
root /usr/share/nginx/html/$domain.com/$subdomain;

You can improve these rules after some play with regexps and handle not .com only domains :)