upstream backend_one{
server vps_1:80;
}
upstream backend_two{
server vps_2:80;
}
upstream backend_three{
server vps_3:80;
}
map $host $backend {
~subdomain_3 backend_three;
~subdomain_2 backend_two;
default backend_one;
}
server {
location / {
proxy_pass http://$backend;
proxy_set_header Host $host;
proxy_redirect off;
}
}