I was trying to get the official php:5.6-apache docker container compiled with GD for a project. GD would install but the JPEG support was missing. I managed to figure out the missing libraries and config in the end.
This is what my docker file looks like now, with the important bits in bold:
FROM php:5.6-apache
RUN apt-get update \
&& apt-get install libpng12-dev libfreetype6-dev libjpeg62-turbo-dev -qy \
&& apt-get clean \
&& rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
RUN docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
&& docker-php-ext-install gd