# inside image php5.6 =[
# extensions of docker-php-ext-install are installed at /usr/local, but apt install on debian's default, /usr/, /etc and elsewhere
#
apt install php5-xdebug

echo "extension=/usr/lib/php5/20131226/xdebug.so" > /usr/local/etc/php/conf.d/docker-php-ext-xdebug.ini
/etc/init.d/apache2 reload

php --info | grep xdebug