You may need to increase the memory available...

[deHakkelaar]

@DanSchaper

you need to increase the amount of memory allowed to PHP

If using default php-cgi and not php-fpm:

How do I increase PHP's memory?

pi@ph5:~ $ sudo nano /etc/php/*/cgi/php.ini [..] ; Maximum amount of memory a script may consume (128MB) ; http://php.net/memory-limit memory_limit = 128M [..] pi@ph5:~ $ sudo service lighttpd restart pi@ph5:~ $ pi@ph5:~ $ php-cgi -i | grep memory_limit <tr><td class="e">memory_limit</td><td class="v">128M</td><td class="v">128M</td></tr>

Not sure how to make that persistent in Docker.