What are the benefits of using docker-php-ext-install?

Question

Docker

Why use docker-php-ext-install in which you need to specify the required libraries:

FROM php:7.0-fpm
RUN apt-get update && apt-get install -y \
        libfreetype6-dev \
        libjpeg62-turbo-dev \
        libpng12-dev \
    && docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
    && docker-php-ext-install -j$(nproc) gd

if you can just do:
apt-get install php5-gd
While the original images weigh more:
official php 5.6.29-fpm - 154 MB
image based on debian:jessie - 74 MB
What is the advantage of docker-php-ext-install?

Answer 1

I would venture to guess that more packages and more recent versions are available in docker-php-ext-install than in the distribution's repository.