NC 15 "Non Trusted Domain Error" behind Docker bridge and Apache vHost

Hello dear nextcloudies all,

i try to get access to my home nextcloud docker image with https and Letsencrypt Certs. Prior configuring the Apache vHost Def for the nextcloud docker image all works fine, for ex. https://.de. After this i set the vHost definition:

ServerName ..de

ProxyPassMatch (.*)(/websocket)$ “ws://172.17.0.4:81/$1$2”
ProxyPass / “http://172.17.0.4:80/
ProxyPassReverse / “172.17.0.4:80>/”

LogLevel debug
Errorlog ${APACHE_LOG_DIR}/nextcloud-error.log
CustomLog ${APACHE_LOG_DIR}/nextcloud-access.log combined

SSLCertificateFile /etc/letsencrypt/live/nextcloud.fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/nextcloud.privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf

Now, the “famous” Non-Trusted-Domain-Error occurs and the nextcloud Log tells me:

… “remoteAddr”:“172.17.0.1”,“user”:"–",“app”,“core” … "Trusted domain error. “172.17.0.1” tried to access using “172.17.0.4” as host. …

What this means? 172.17.0.1 is the IP from my docker bridge. What should i set in the config/config.php
or for the occ trusted_domains setting?

Solution for this mistake in config.php

‘trusted_proxies’ => [‘172.17.0.1’],
‘trusted_domains’ => ‘FQDN’,
‘overwritecondaddr’ => ‘^172.17.0.1$’,

and all works fine!