Docker + reverse proxy with subdirectory

Hello,

Spent way too much this on trying to figure this out. I hope someone wanted to do the same and managed to do it.

Using docker-compose file and everything is loaded and reachable at "http://192.168.28.53:7880/app". Now I wish to open access to public using nginx reverse proxy on which I also have my SSL certificate. Using following rule:

```
location /docspell/
{
client_max_body_size 100M;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forward-Proto http;
proxy_pass http://192.168.28.53:7880;
}
```

When I try to open: https://domain.com/docspell/ I get a "Not found". Looking at logs I can see it tried to open /docspell and got 404 back. Where to change base url to include /docspell for all the URL calls? I looked in files under /var/solr but can not find anything there.

Thank you.