Roundcube webmail is accessed through the nginx reverse proxy in the
front container. Each access logline logged by apache2 in the roundcube
container did not contain the actual client IP address, but the IP
address of the front container, for example:
> 192.168.203.3 - - [28/May/2022:12:33:52 +0000] "POST /?_task=mail&_action=refresh HTTP/1.1" 200 677 "https://[REDACTED]/roundcube/?_task=mail&_mbox=INBOX" "Mozilla/5.0 (X11; Linux x86_64; rv:100.0) Gecko/20100101 Firefox/100.0"
^
IP address of the front container
By enabling the apache2 remoteip module and configuring it to get the
actual client IP address from the X-Forwarded-For header, it logs the
correct client IP address to the access log.
Pim van den Berg