nginx reverse proxy example

nginx.conf

upstream main {
    server web1.local:80;
    server web2.local:80;
    server web3.local:80;
}
location /some/path/ {
    if ($host ~* "(.+)\.test\.bugua\.com$") {
        set $new_host $1.bugua.com;
    }
    proxy_set_header Host $new_host;
    #proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Accept-Encoding "";
    proxy_buffers 16 4k;
    proxy_buffer_size 2k;
    #proxy_pass http://localhost:8000;
    proxy_pass http://main;
}