in the console:
cd etc/php7/conf.d
vi local.ini
change contents to:
extension = fileinfo
expose_php = Off
error_reporting = E_ALL
display_errors = Off
log_errors = On
error_log = /dev/stderr
date.timezone = UTC
allow_url_fopen = On
post_max_size = 32M
upload_max_filesize = 32M
opcache.max_accelerated_files = 7963
opcache.validate_timestamps = On
opcache.save_comments = 0
opcache.load_comments = 0
opcache.fast_shutdown = 1
opcache.enable_file_override = On
opcache.revalidate_freq = 0
save and restart container, php will no longer be cached.