Best way to reduce custom docker image size

Question

I created a custom Docker image based on the official PHP FPM image php:7.0.14-fpm-alpine

I wanted to keep the image size small, so I went for the official version of alpinePHP-FPM, as it weighs only 27 MB .

I installed only a few additional packages through mine Dockerfile, and the image increased in size to 277.5 MB . Here is my Docker file:

FROM php:7.0.14-fpm-alpine

COPY ./config/www-pool.conf /usr/local/etc/php-fpm.d/www.conf
COPY ./scripts/download-composer.sh /root/download-composer.sh

WORKDIR /root

RUN chmod +x download-composer.sh \
    && ./download-composer.sh \
    && mv composer.phar /usr/local/bin/composer

RUN ["mkdir", "/var/log/php-fpm"]

RUN apk --update add \
      autoconf g++ make \
      openssl-dev \
      libxml2-dev

RUN pecl install \
        xdebug \
        mongodb

RUN docker-php-ext-enable \
        xdebug.so \
        mongodb.so

RUN  docker-php-ext-install \
        pdo_mysql \
        soap

RUN addgroup sudo
RUN adduser -S luqo33 -G sudo
RUN echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers

277.5 MB is a tenfold increase in size compared to the base image. Besides Composer, I needed several PHP extensions:

• Mongodb
• Xdebug
• bp
• soap

, . , dev, pecl (openssl-dev, libxml2-dev), .

, PHP-FPM ?

Answer 1

, . , . Alpine Linux ( APK) :

rm -rf /var/cache/apk/*

, . (0,8 ).

FROM php:7.0.14-fpm-alpine

WORKDIR /root

RUN ["mkdir", "/var/log/php-fpm"]

RUN apk --update add \
      autoconf g++ make \
      openssl-dev \
      libxml2-dev \
  && rm -rf /var/cache/apk/*

, 267 .

REPOSITORY             TAG      IMAGE ID       CREATED          SIZE
php-fpm-alpine-test2   latest   b87f5e2d629d   23 seconds ago   267.1 MB
php-fpm-alpine-test1   latest   8ff7df8bebea   6 minutes ago    267.9 MB

- , .

Step 4 : RUN apk --update add       autoconf g++ make       openssl-dev       libxml2-dev   && rm -rf /var/cache/apk/*
 ---> Running in 037a929d9e6a
fetch http://dl-cdn.alpinelinux.org/alpine/v3.4/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.4/community/x86_64/APKINDEX.tar.gz
(1/23) Installing m4 (1.4.17-r1)
(2/23) Installing perl (5.22.2-r0)
(3/23) Installing autoconf (2.69-r0)
(4/23) Installing libgcc (5.3.0-r0)
(5/23) Installing libstdc++ (5.3.0-r0)
(6/23) Installing binutils-libs (2.26-r0)
(7/23) Installing binutils (2.26-r0)
(8/23) Installing gmp (6.1.0-r0)
(9/23) Installing isl (0.14.1-r0)
(10/23) Installing libgomp (5.3.0-r0)
(11/23) Installing libatomic (5.3.0-r0)
(12/23) Installing pkgconf (0.9.12-r0)
(13/23) Installing pkgconfig (0.25-r1)
(14/23) Installing mpfr3 (3.1.2-r0)
(15/23) Installing mpc1 (1.0.3-r0)
(16/23) Installing gcc (5.3.0-r0)
(17/23) Installing musl-dev (1.1.14-r14)
(18/23) Installing libc-dev (0.7-r0)
(19/23) Installing g++ (5.3.0-r0)
(20/23) Installing zlib-dev (1.2.8-r2)
(21/23) Installing libxml2-dev (2.9.4-r0)
(22/23) Installing make (4.1-r1)
(23/23) Installing openssl-dev (1.0.2j-r0)
Executing busybox-1.24.2-r11.trigger
OK: 220 MiB in 48 packages

, apk 220 MiB .

- , , , . , dev, , automake ..

, RUN . , apk, RUN, . , , - - .

RUN apk --update add \
      autoconf g++ make \
      openssl-dev \
      libxml2-dev \
    && pecl install \
        xdebug \
        mongodb \
    && docker-php-ext-enable \
        xdebug.so \
        mongodb.so \
    && docker-php-ext-install \
        pdo_mysql \
        soap \
    && apk del autoconf g++ make openssl-dev libxml2-dev \
    && rm -rf /var/cache/apk/*