[BUG] Invalid HTTP Request

When trying to access the Web UI from https://domain.com/youtube-dl I get a 502 error and see the following in the logs

WARNING:  Invalid HTTP request received.
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/uvicorn/protocols/http/h11_impl.py", line 170, in handle_events
    event = self.conn.next_event()
  File "/usr/local/lib/python3.9/site-packages/h11/_connection.py", line 443, in next_event
    exc._reraise_as_remote_protocol_error()
  File "/usr/local/lib/python3.9/site-packages/h11/_util.py", line 76, in _reraise_as_remote_protocol_error
    raise self
  File "/usr/local/lib/python3.9/site-packages/h11/_connection.py", line 425, in next_event
    event = self._extract_next_receive_event()
  File "/usr/local/lib/python3.9/site-packages/h11/_connection.py", line 367, in _extract_next_receive_event
    event = self._reader(self._receive_buffer)
  File "/usr/local/lib/python3.9/site-packages/h11/_readers.py", line 75, in maybe_read_from_IDLE_client
    return Request(
  File "/usr/local/lib/python3.9/site-packages/h11/_events.py", line 71, in __init__
    self._validate()
  File "/usr/local/lib/python3.9/site-packages/h11/_events.py", line 142, in _validate
    raise LocalProtocolError("Found multiple Host: headers")
h11._util.RemoteProtocolError: Found multiple Host: headers

I’m running NGINX with LetsEncrypt and my main domain is behind a CF proxy and this had never been an issue.

This is my nginx.conf

## Version 2020/09/01 - Changelog: https://github.com/linuxserver/docker-swag/commits/master/root/defaults/nginx.conf

user abc;
worker_processes 4;
pid /run/nginx.pid;
include /etc/nginx/modules/*.conf;

events {
	worker_connections 768;
	# multi_accept on;
}

http {

	##
	# Basic Settings
	##

	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 65;
	types_hash_max_size 2048;
	variables_hash_max_size 2048;
	large_client_header_buffers 4 16k;
	client_max_body_size 0;
	include /etc/nginx/mime.types;
	default_type application/octet-stream;
	##
	# Logging Settings
	##
	access_log /config/log/nginx/access.log;
	error_log /config/log/nginx/error.log;
	##
	# Gzip Settings
	##
	gzip on;
	gzip_disable "msie6";
	##
	# CF Real IP
	##
	include cf_real-ip.conf;
	real_ip_header X-Forwarded-For;
	##
	# Theme Park
	##
	map $host $theme {
    default organizr-dark;
}
	##
	# WebSocket proxying
	##
	map $http_upgrade $connection_upgrade {
		default upgrade;
		''      close;
	}
	##
	# Virtual Host Configs
	##
	include /etc/nginx/conf.d/*.conf;
	include /config/nginx/site-confs/*;
	lua_load_resty_core off;
}
daemon off;

This is my proxy.conf

## Version 2020/09/01 - Changelog: https://github.com/linuxserver/docker-swag/commits/master/root/defaults/proxy.conf

client_body_buffer_size 128k;

#Timeout if the real server is dead
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;

# Advanced Proxy Config
send_timeout 5m;
proxy_read_timeout 240;
proxy_send_timeout 240;
proxy_connect_timeout 240;

# TLS 1.3 early data
proxy_set_header Early-Data $ssl_early_data;

# Basic Proxy Config
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 https;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Ssl on;
proxy_redirect  http://  $scheme://;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;
#proxy_cookie_path / "/; HTTPOnly; Secure"; # enable at your own risk, may break certain apps
proxy_cache_bypass $cookie_session;
proxy_no_cache $cookie_session;
proxy_headers_hash_bucket_size 128;
proxy_headers_hash_max_size 1024;

## Plex Login Error - API Connection Failed Fix?
proxy_buffer_size 128k;
proxy_busy_buffers_size 256k;
proxy_buffers 4 256k;

This is my ssl.conf

## Version 2020/06/17 - Changelog: https://github.com/linuxserver/docker-swag/commits/master/root/defaults/ssl.conf

### Mozilla Recommendations
# generated 2020-06-17, Mozilla Guideline v5.4, nginx 1.18.0-r0, OpenSSL 1.1.1g-r0, intermediate configuration
# https://ssl-config.mozilla.org/#server=nginx&version=1.18.0-r0&config=intermediate&openssl=1.1.1g-r0&guideline=5.4

ssl_session_timeout 1d;
ssl_session_cache shared:MozSSL:10m;  # about 40000 sessions
ssl_session_tickets off;

# intermediate configuration
ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
ssl_prefer_server_ciphers off;

# OCSP stapling
ssl_stapling on;
ssl_stapling_verify on;


### Linuxserver.io Defaults

# Certificates
ssl_certificate /config/keys/letsencrypt/fullchain.pem;
ssl_certificate_key /config/keys/letsencrypt/privkey.pem;
# verify chain of trust of OCSP response using Root CA and Intermediate certs
ssl_trusted_certificate /config/keys/letsencrypt/fullchain.pem;

# Diffie-Hellman Parameters
ssl_dhparam /config/nginx/dhparams.pem;

# Resolver
resolver 127.0.0.11 valid=30s; # Docker DNS Server

# Enable TLS 1.3 early data
ssl_early_data on;

# HSTS, remove # from the line below to enable HSTS
add_header Strict-Transport-Security "max-age=15770000; includeSubDomains; preload" always;

# Optional additional headers
add_header Content-Security-Policy "upgrade-insecure-requests";
add_header X-Frame-Options "SAMEORIGIN" always;
add_header X-XSS-Protection "1; mode=block" always;
add_header X-Content-Type-Options "nosniff" always;
add_header X-UA-Compatible "IE=Edge" always;
add_header Cache-Control "no-transform" always;
add_header Referrer-Policy "same-origin" always;
add_header Content-Security-Policy "frame-ancestors https://domain.xyz";

[blackerking]

I made a pull request: https://github.com/linuxserver/reverse-proxy-confs/pull/287

[angrycuban13]

Commenting this line out fixed it!

    proxy_set_header Host $upstream_app:8080;

@blackerking maybe have LSIO update the .conf for youtube-dl?