PHP7 with gd (jpeg enabled)

Dockerfile

FROM php:fpm-alpine

RUN apk update \
    && apk upgrade \
    && apk add --no-cache \
        freetype \
        libpng \
        libjpeg-turbo \
        freetype-dev \
        libpng-dev \
        jpeg-dev \
        libjpeg \
        libjpeg-turbo-dev

RUN docker-php-ext-configure gd \
        --with-freetype-dir=/usr/lib/ \
        --with-png-dir=/usr/lib/ \
        --with-jpeg-dir=/usr/lib/ \
        --with-gd

RUN NUMPROC=$(grep -c ^processor /proc/cpuinfo 2>/dev/null || 1) \
    && docker-php-ext-install -j${NUMPROC} gd