I spent a bit of time on this and was able to get cron to work but it would be lost as soon as the container is restarted.
Cron is wiped if the container is recreated for any reason, the encryption key is generated too late in the setup process to recreate cron in entrypoint and cron itself can't be stored in a volume.
The cron tasks themselves have to run as root inside the container so it would end up looking like this (Ignore the timings as I changed it to make it trigger faster)
* * * * root /usr/bin/php /var/www/html/cron.php REDACTED
* * * * * root /usr/bin/php /var/www/html/cron_ticket_email_parser.php REDACTED
* * * * * root /usr/bin/php /var/www/html/cron_mail_queue.php REDACTED
This was enough to get it working without any errors (including mailing out) but it's running as root…
Whois and php-gd are both missing,
Whois is easily fixed but even after installing php-gd the checks in setup.php still say it isn't installed.
PHP is also outdated but this doesn't appear to impact much of anything
Making this work would require ITFlow to generate the key much earlier or be able to supply your own key which would require I expect significant dev work on your side.
I don't have alot of time currently to invest into it but in saying that the work needed on the docker itself is pretty minimal, but even then cron tasks running as root is enough for me to not use it in a docker anyway.
