Valentin:

Here is a snippet of the config:

server {
listen 80;

map $user $user_fastcgi_port {
default 9000;
bob 9001;
john 9002;
kelly 9003;
}

server_name $user\.my\.domain\.com$;

root /srv/www/users/$user/wp;

index index.php;

access_log /var/log/nginx/users/$user.access.log;
error_log /var/log/nginx/error.log;

include /etc/nginx/excludes.conf;
include /etc/nginx/wordpress.conf;
include /etc/nginx/expires.conf;
}

I am getting the following error though:

nginx: [emerg] "map" directive is not allowed here in /etc/nginx/conf.d/core.conf:4
nginx: configuration file /etc/nginx/nginx.conf test failed