django invalid HTTP HOST header

March 25, 2021

Symtoms

Invalid HTTP_HOST header: 'web_backend_1:22222'. 
The domain name provided is not valid according to RFC 1034/1035.

Cause

I used react webpack proxy server
```
"proxy": "http://web_backend_1:22222"
```
settings.py
```
ALLOWED_HOSTS = [ 'web_backend_1' ] ??
```

Solution

clean browser history
set ALLOWED_HOSTS properly
rebuild image, rerun server

Issue

in docker container, docker container name can be used?