Nginx proxy_redirect with relative paths

I am not a big specialist in nginx administration, I am just a developer. I have two backends running in docker. Let me name them

• backend1:8080
• backend2:8081

Also I have Nginx exposing 443 port with letsencrypt certificated installed. My configuration of Nginx is (env variable FQDN is something like example.com)

upstream backend1 {
  server backend1:8080;
}

upstream backend2 {
  server backend2:8081;
}

server {
  listen 443 ssl;
  
  server_name ${FQDN} www.${FQDN};
  
  ssl_certificate /etc/letsencrypt/live/${FQDN}/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/${FQDN}/privkey.pem;
  ssl_session_cache shared:SSL:1m;
  ssl_session_timeout  5m;
  ssl_ciphers  HIGH:!aNULL:!MD5;
  ssl_prefer_server_ciphers   on;

  if ($server_port = 80) { set $https_redirect 1; }
  if ($host ~ '^www\.') { set $https_redirect 1; }
  if ($https_redirect = 1) { return 301 https://${FQDN}$request_uri; }
  
  location /path1/ {
    
    proxy_pass http://backend1/;

    proxy_redirect ~^/(.*) $scheme://$http_host/path1/$1;
    
    proxy_http_version 1.1;
    
    proxy_pass_header Set-Cookie;
    proxy_pass_header Cookie;
    proxy_pass_header X-Forwarded-For;

    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forward-Proto http;
    proxy_set_header X-Nginx-Proxy true;
    add_header       X-Upstream      $upstream_addr;
  }
  
  location /path2/ {
    
    proxy_pass http://backend2/;

    proxy_redirect ~^/(.*) $scheme://$http_host/path2/$1;
    
    proxy_http_version 1.1;
    
    proxy_pass_header Set-Cookie;
    proxy_pass_header Cookie;
    proxy_pass_header X-Forwarded-For;

    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forward-Proto http;
    proxy_set_header X-Nginx-Proxy true;
    add_header       X-Upstream      $upstream_addr;
  }
}

I want that if I request https://exapmle.com/path1/ then Nginx should go to http://backend1:8080/ and return me response from that server. The problem is that backend1 (as well as backend2) can response with 302 and redirect to some path eg. /login. Nginx redirects my browser to https://exapmle.com/login but I want it to redirect me to https://exapmle.com/path1/login Could you help me please and point to the error that I made in my configuration. I've reviwed all similar questions in SO and not found any solution. Also I've explored Nginx documentation and also have not found the answer.

I have the line proxy_redirect ~^/(.*) $scheme://$http_host/path1/$1; and I suppose it must do the work I want.

BTW I cannot occupy / location (create configuration for the root path) in my Nginx config as it is reserved to another backend server. Thanks in advance.

Maybe it is because of the misspelled X-Forwarded-Headers in your configuration. It should be X-Forwarded-* instead of X-Forward-*.