Migration from NGINX proxy to HAProxy - issue with headers

Help!
1

Hello together,
I try to do migration from NGINX to HAProxy. But I have an issue with headers.

When I use NGINX so the proxied request looks like that:
"POST /afterslash/wwv_flow.ajax HTTP/1.1" 204 0 "https://someurl.com/afterslash/f?p=SOMESTRING:REGISTR:0::NO::EMAIL,HASH:anemail%40email.com,D96417C63EC1C4E8CAF113E119C4C5C371520523" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0"

When I use HAProxy it looks:
"POST /afterslash/wwv_flow.ajax HTTP/1.1"

There is a part that missing. I guess that i have to add some “http-request set-header” into my backend, but I am not sure which kind of.

NGINX has this setting related to headers:
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_hide_header X-Powered-By;
proxy_set_header Accept-Encoding “”; #needed for sub_filters

I would say that I could to do this setting below, but I am not sure if rest of rules mentioned above are important as well…
http-request set-header https://someurl.com
http-request set-header X-Forwarded-For %[src]

Let me admit that I can test it just in night because of impact to end users… This is the reason why I am trying to find out a hint here.

Really thanks for any help in advance.

2

And is unclear what you mean by “looks like”. Where is this output from exactly? Backend server logs? What exactly are you logging there? Referer and User Agent? This is probably not showing the root cause, but some consequence.

It is very unclear what is actually expected at this point.

Please provide the entire configuration, haproxy logs and the output of haproxy -vv.