user www www;
worker_processes 2;
error_log /var/log/nginx/error.log crit;
pid /var/run/nginx.pid;
events {
    worker_connections 1024;
}
http {

 upstream backend {
         server unix:/tmp/php-fpm.sock;
 }
    include /usr/local/etc/nginx/mime.types;
    default_type application/octet-stream;
    access_log off;
    server_tokens off;
    sendfile on;
    client_max_body_size 200m;
    client_body_buffer_size 1m;
    keepalive_timeout 1;
    port_in_redirect off;
    gzip on;
    gzip_http_version 1.1;
    gzip_vary on;
    gzip_comp_level 6;
    gzip_proxied any;
    gzip_types text/plain text/css application/json application/x-javascript application/xml application/xml+rss text/javascript;
    gzip_buffers 16 8k;
    gzip_disable "MSIE [1-6].(?!.*SV1)";
    include /usr/local/etc/nginx/conf.d/*.conf;
}

And sample config for one domain: