Reverse proxy connection upgrade header lowercase issue

[eyups]

Describe the issue you are experiencing

1. Setup a CDN -> NGINX Home Assistant SSL proxy -> HA configuration
2. Some CDN's (In my case my Keenetic modem's KeenDNS dynamic DNS service) doesn't accept

proxy_set_header Connection upgrade;

with lowercase. 3. Instead they accept ->

proxy_set_header Connection Upgrade;

So https://github.com/home-assistant/addons/blob/master/nginx_proxy/rootfs/etc/nginx.conf needs to be changed with:

map $http_upgrade $connection_upgrade {
        default Upgrade;
        ''      close;
    }

This helped me solve my issue putting additional nginx server between CDN and HA server to be able to add access control lists etc.

I found this information on nginx's blog post. (https://www.nginx.com/blog/websocket-nginx/)

What type of installation are you running?

Home Assistant OS

Which operating system are you running on?

Home Assistant Operating System

Which add-on are you reporting an issue with?

NGINX Home Assistant SSL proxy

What is the version of the add-on?

3.8.0

Steps to reproduce the issue

1. Setup a CDN -> NGINX Home Assistant SSL proxy -> HA configuration
2. Some CDN's (In my case my Keenetic modem's KeenDNS dynamic DNS service) doesn't accept

proxy_set_header Connection upgrade;

with lowercase. 3. Instead they accept ->

proxy_set_header Connection Upgrade;

It gives 502 Bad Gateway error when we try to reach the page

System Health information

System Information

version	core-2024.2.1
installation_type	Home Assistant OS
dev	false
hassio	true
docker	true
user	root
virtualenv	false
python_version	3.12.1
os_name	Linux
os_version	6.1.73-haos-raspi
arch	aarch64
timezone	Europe/Istanbul
config_dir	/config

Home Assistant Community Store

GitHub API	ok
GitHub Content	ok
GitHub Web	ok
GitHub API Calls Remaining	4894
Installed Version	1.33.0
Stage	running
Available Repositories	1405
Downloaded Repositories	15

Home Assistant Cloud

logged_in	false
can_reach_cert_server	ok
can_reach_cloud_auth	ok
can_reach_cloud	ok

Home Assistant Supervisor

host_os	Home Assistant OS 12.0
update_channel	stable
supervisor_version	supervisor-2024.02.1
agent_version	1.6.0
docker_version	24.0.7
disk_total	234.0 GB
disk_used	9.7 GB
healthy	true
supported	true
board	rpi4-64
supervisor_api	ok
version_api	ok
installed_addons	Home Assistant Google Drive Backup (0.112.1), ESPHome (2023.12.9), RTSP Simple Server Add-on (v0.17.6), Advanced SSH & Web Terminal (17.1.0), File editor (5.8.0), Samba share (12.3.0), eufy-security-ws (1.8.0), NGINX Home Assistant SSL proxy (3.8.0), Let's Encrypt (5.0.15), EYUPS NGINX Home Assistant SSL proxy (3.8.0)

Dashboards

dashboards	1
resources	5
views	3
mode	storage

Recorder

oldest_recorder_run	February 18, 2024 at 9:02 AM
current_recorder_run	March 10, 2024 at 7:14 PM
estimated_db_size	811.72 MiB
database_engine	sqlite
database_version	3.44.2

Sonoff

version	3.5.4 (a4a8c5f)
cloud_online	1 / 1
local_online	1 / 1

Xiaomi Miot Auto

component_version	0.7.16
can_reach_server	ok
can_reach_spec	ok
logged_accounts	1
total_devices	4

Anything in the Supervisor logs that might be useful for us?

No response

Anything in the add-on logs that might be useful for us?

No response

Additional information

No response