Nginx is redirecting to the wrong url

Question

I have been trying to figure this out for almost 6 months on and off I am at a loss. I have read every article I could on stack overflow even remotely related to my issue and nothing works. I have one machine running redmine and bookstack. I have nginx on that machine and configured to use redmine.home.mydomain.com and kb.home.mydomain.com, that works great. no issue when I type those in.

The problem I am having it when I type try to redirect to that URL from my external facing nginx server. I have redmine.mydomain.com and kb.mydomain.com. The redmine one works great but the kb one redirects to redmine. I can't figure out why.

I have checked the response headers in several browsers and it gets redirected to https://kb.mydomain.com but the response from that call is the redmine home page. Even though it should be redirecting to kb.home.mydomain.com which works fine if I type that in directly.

Bookstack config

# redirect to ssl
server {
  listen 80;
  listen [::]:80;
  server_name kb.mydomain.com www.kb.mydomain.com;
  return 301 https://$server_name$request_uri;
}

server {
  listen 443 ssl;
  listen [::]:443 ssl;
  server_name kb.mydomain.com www.kb.mydomain.com;
  client_max_body_size 50M;


  ssl on;
  ssl_certificate /etc/letsencrypt/live/mydomain.com-0001/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/mydomain.com-0001/privkey.pem;

  access_log  /var/log/nginx/kb.access;
  error_log   /var/log/nginx/kb.error;

  location / {
    proxy_pass http://kb.home.mydomain.com/;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
  }
}

redmine config.

# redirect to ssl  
server {                      
  listen 80;
  listen [::]:80;
  server_name redmine.mydomain.com www.redmine.mydomain.com;
  return 301 https://$server_name$request_uri; 
}                                                                             

server {                                                                      
  listen 443 ssl http2;                                                       
  listen [::]:443 ssl http2;                                                  
  server_name redmine.mydomain.com www.redmine.mydomain.com;                  
  client_max_body_size 50M;                                                   
  ssl_certificate /etc/letsencrypt/live/mydomain.com-0001/fullchain.pem;      
  ssl_certificate_key /etc/letsencrypt/live/mydomain.com-0001/privkey.pem;    
  location / {
    proxy_pass http://redmine.home.mydomain.com;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr; 
  }                                                                           
}   

I am lost as to why it is redirecting to redmine any help would be greatly appreciated.

Answer 1

It is happening cause you need to set the correct Header HTTP Host to works in your backend environment, how you did it wrong, you've even been inside the default website .

server {
  listen 80;
  listen [::]:80;
  server_name kb.mydomain.com www.kb.mydomain.com;
  return 301 https://$server_name$request_uri;
}

server {
  listen 443 ssl;
  listen [::]:443 ssl;
  server_name kb.mydomain.com www.kb.mydomain.com;
  client_max_body_size 50M;


  ssl on;
  ssl_certificate /etc/letsencrypt/live/mydomain.com-0001/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/mydomain.com-0001/privkey.pem;

  access_log  /var/log/nginx/kb.access;
  error_log   /var/log/nginx/kb.error;

  location / {
    proxy_pass http://kb.home.mydomain.com/;
    proxy_set_header Host kb.home.mydomain.com;
    proxy_set_header X-Real-IP $remote_addr;
  }
}

redmine config.

server {                      
  listen 80;
  listen [::]:80;
  server_name redmine.mydomain.com www.redmine.mydomain.com;
  return 301 https://$server_name$request_uri; 
}                                                                             


server {                                                                      
  listen 443 ssl http2;                                                       
  listen [::]:443 ssl http2;                                                  
  server_name redmine.mydomain.com www.redmine.mydomain.com;                  
  client_max_body_size 50M;                                                   
  ssl_certificate /etc/letsencrypt/live/mydomain.com-0001/fullchain.pem;      
  ssl_certificate_key /etc/letsencrypt/live/mydomain.com-0001/privkey.pem;    
  location / {
    proxy_pass http://redmine.home.mydomain.com;
    proxy_set_header Host redmine.home.mydomain.com;
    proxy_set_header X-Real-IP $remote_addr; 
  }                                                                           
}