I am migrating mail servers from OVH/Centos7 to AWS/Amazon Linux; part of my setup uses roundcube webmail.
I have copied all of my config and supporting files from one instance to the other, however can not seem to make the webmail app load as expected. Anything and everything produces a 500 with no useful errors displayed anywhere.
All apps and subdirectories are owned by apache:apache
With the following error config in php.ini
display_errors = On
error_reporting = E_ALL
log_errors = On
This is the ONLY log entry created when navigating to my URL:
w.x.y.z - - [27/Dec/2018:03:56:03 +0000] "GET / HTTP/1.1" 500 - "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36"
The log entry clearly shows the 500, but produces no errors. In addition, the error log file within the roundcube directory is also empty.
The response to the client is empty, just a 500.
$curl https://mail.example.com/
Header is 500:
$curl https://mail.example.com/ --head
HTTP/1.1 500 Internal Server Error
....
If I cd to the roundcube directory and try to evaluate the index, it returns nothing:
$cd /path/to/roundcube
$php index.php
$
I have tried to disable every single roundcube plugin, in config/config.inc.php
$config['plugins'] = array();
Every single other app and web page works, after the transplant; roundcube is the only thing which is throwing 500's and not producing any error messages...
syslog is empty of relevant messages.
What can I possibly do to further investigate why this might be failing?