Nginx. Directory of index is forbiden - nginx

Question

I have load balancing nginx server 192.168.2.168 with the following nginx config:
upstream balancer {
server 192.168.2.165;
server 192.168.2.166 backup;
}
server {
listen 80;
server_name 192.168.2.168;
error_log /var/log/nginx/balancer-error_log;
location /something {
proxy_pass http://balancer;
}
}
Then I try 192.168.2.168/something it gives 403 Forbiden
tailf /var/log/error.log on the 192.168.2.165 shows:
*47 directory index of "/usr/share/nginx/html/glpi/" is forbidden, client: 192.168.2.168, server: localhost, request: "GET /glpi/ HTTP/1.0", host: "balancer"
But if I replace http://balancer with http://192.168.2.165 it works fine.
proxy_pass http://192.168.2.165;
What am I doing wrong and how to make upsream servers work?

Answer 1

The problem is solved using server_name balancer.home; instead of server_name 192.168.2.168; + I added some headers.
Here is my config:
upstream backend {
server 192.168.2.165;
server 192.168.2.166;
server 192.168.2.167 backup;
}
server {
listen 80;
server_name balancer.home;
return 301 https://$server_name$request_uri;
}
server {
listen 443 ssl http2;
server_name balancer.home;
ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;
ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;
error_log /var/log/nginx/balancer-error_log;
access_log /var/log/nginx/balancer-access_log;
location / {
proxy_pass_header Server;
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 X-Forwarded-Proto $scheme;
proxy_pass http://backend;
}
}
PS: On upstream servers, the same server_name as on the balance server (domain name) should be specified.