dev mode ignoring `X-Forwarded-Proto` and `X-Forwarded-Host` headers

Discussed in https://github.com/sveltejs/kit/discussions/11900

^{Originally posted by yannishin February 26, 2024}
I expected the return from the Hook to be event.url.host=ui.foo.com, event.url.protocol=https:, but it is returning event.url.host=ui_server/ui, event.url.protocol=http:.

How should I solve this issue?

Given that event.request.headers.get("X-Forwarded-Host") and event.request.headers.get("X-Forwarded-Proto") are returning null, it seems that the node server(adapter-node.) is not recognizing the X-Forwarded-??? headers.

For reference, the API Server developed with spring boot is correctly returning ui.foo.com, https:.

This is Nginx Config

upstream ui_server {
ip_hash;
ui.foo.com:17001;
keepalive 100;
}

location /ui {

    proxy_pass  http://ui_server/ui;

    proxy_http_version 1.1;
    proxy_set_header Connection $connection_upgrade;
    proxy_set_header Upgrade $http_upgrade;
    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_set_header    X-Forwarded-Host $host;
    proxy_set_header Forwarded "for=$proxy_add_x_forwarded_for; host=$host; proto=$scheme";

    charset utf-8;

    access_log /opt/naon/app/nginx/logs/ui-access.log postdata;
  }

Start by reproducing the issue in the adapter-node dev server with the supplied Nginx configuration and forwarded headers. Inspect how the server derives event.url from the request, and consider the work done when event.url.host and event.url.protocol reflect X-Forwarded-Host and X-Forwarded-Proto.