Custom DNS breaks Reverse proxy configuration and activation emails.

Hi Team!

I’ve setup Community Server using Docker on custom ports instead of 80 and 443 to be able to install other apps on our Linux server.

onlyoffice-community-server   onlyoffice4enterprise/communityserver-ee:8.9.2.27   3306/tcp, 5280/tcp, 9865-9866/tcp, 9871/tcp, 9882/tcp, 9888/tcp, 0.0.0.0:5222->5222/tcp, 0.0.0.0:8081->80/tcp, 0.0.0.0:4431->443/tcp

I’ve used an Apache Proxy virtual host to redirect to the container (we only need community server, no mail server, no document server).

• If I set the Custom DNS setting to our hostname (https://onlyoffice.xxxxxx.com), this breaks mailing system and activation email links.
• If I don’t set it, I get wrong activation email link. This seems legit because we are inside a Docker container. 450042771ab5 is the container internal hostname.

http://450042771ab5:8081/confirm.aspx?type=Activation

So the problem is why does OnlyOffice breaks my outgoing emails when I set Custom DNS ? Because I don’t want my users to edit manually their activation URL with the real hostname and port.

Here is my Apache configuration to proxy to the Docker Community Server container.

<VirtualHost *:80>
    ServerAdmin xxxxxxxxxxxx
    ServerName onlyoffice.xxxxxx.com

    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
</VirtualHost>
<IfModule mod_ssl.c>
<VirtualHost *:443>
    ServerName onlyoffice.xxxxxx.com
    ServerAdmin xxxxxxxxxxxx

    ProxyPass / http://localhost:8081/
    ProxyPassReverse / http://localhost:8081/

	SSLEngine on
	SSLCertificateFile /etc/letsencrypt/live/onlyoffice.xxxxxx.com/fullchain.pem
        SSLCertificateKeyFile /etc/letsencrypt/live/onlyoffice.xxxxxx.com/privkey.pem
        SSLCertificateChainFile /etc/letsencrypt/lets-encrypt-x3-cross-signed.pem
</VirtualHost>
</IfModule>

Thanks for your help.

[ambroisemaupate]

Response timeout issue seems to be gone after upgrading to latest CommunityServer Docker image version (v9.0.0.300).

[libardoram]

Try to add :

ProxyPreserveHost On

after the ServerName subdomain.domain.com I use nguni for the reverse proxy, but I think this should work for you.