inanzzz | Copying Symfony application into docker container with multi-stage builds

In this example we are going to run composer to install Symfony application dependencies then copy vendor folder and the rest of the application files into container image. With this way our image will always come with the application by default so all we have to do is create a container and start using it. This is a well known practise but I just wanted to touch upon a basic implementation. The main purpose is to isolate application code and not expose it to host OS. I am not going to list the benefits here because they all have been written on the Internet. The main problem with this solution is, the size of the final docker image will depend on the application and vendor folder size.

Structure

.
├── bin
│   └── ...
├── composer.json
├── composer.lock
├── Readme.md
├── symfony.lock
├──.env
├──.gitignore
├──.dockerignore
├── config
│   └── ...
├── docker
│   ├── docker-compose.yml
│   ├── Makefile
│   ├── nginx
│   │   ├── app.conf
│   │   ├── Dockerfile
│   │   └── nginx.conf
│   └── php
│       ├── Dockerfile
│       ├── init.sh
│       ├── php.ini
│       └── www.conf
├── public
│   └── index.php
├── src
│   └── ...
├── var
│   └── ...
└── vendor
      └── ...

Files

I am just showing the content of important files. The rest is not too important.

.dockerignore

config/packages/dev/
config/packages/test/
var/
vendor/
.dockerignore
.gitignore
*.md

.git/
.idea/
.DS_Store/

docker-compose.yml

version: "3.4"

services:

  sport_php:
    build:
      context: ".."
      dockerfile: "docker/php/Dockerfile"
    hostname: "sport-php"
    environment:
      PS1: "\\u@\\h:\\w\\$$ "

  sport_nginx:
    build:
      context: ".."
      dockerfile: "docker/nginx/Dockerfile"
    hostname: "sport-nginx"
    ports:
      - "1080:80"
    depends_on:
      - "sport_php"
    environment:
      PS1: "\\u@\\h:\\w\\$$ "

Makefile

build:
	@docker-compose build

up:
	@docker-compose up -d

nginx/Dockerfile

FROM nginx:1.15.8-alpine

WORKDIR /app

COPY public/index.php /app/public/index.php

COPY docker/nginx/app.conf /etc/nginx/conf.d/default.conf
COPY docker/nginx/nginx.conf /etc/nginx/nginx.conf

php/Dockerfile

#
# STAGE 1: composer
#
FROM composer:1.8.5 as composer

COPY composer.* /app/

RUN set -xe \
 && composer install --no-dev --no-scripts --no-suggest --no-interaction --prefer-dist --optimize-autoloader

COPY . /app

RUN composer dump-autoload --no-dev --optimize --classmap-authoritative

#
# STAGE 2: php
#
FROM php:7.2.13-fpm-alpine3.8

RUN apk update \
 && apk add --no-cache $PHPIZE_DEPS \
    git \
    zip \
    unzip \
 && docker-php-ext-install \
    opcache \
    pdo_mysql \
 && docker-php-ext-enable \
    opcache \
 && rm -rf \
    /var/cache/apk/* \
    /var/lib/apt/lists/*

WORKDIR /app

COPY . /app

COPY --from=composer /app/vendor /app/vendor

COPY docker/php/php.ini /usr/local/etc/php/conf.d/php.override.ini
COPY docker/php/www.conf /usr/local/etc/php-fpm.d/www.conf
COPY docker/php/init.sh /usr/local/bin/init.sh

RUN chmod +x /usr/local/bin/init.sh

CMD ["/usr/local/bin/init.sh"]

php/init.sh

#!/bin/sh
set -e

bin/console cache:warm

php-fpm --nodaemonize

Build and check

$ make -sC docker/ build up

$ docker images
REPOSITORY           TAG                    IMAGE ID            CREATED             SIZE
docker_sport_php     latest                 c7d3ba4a4c3a        22 hours ago        302MB
docker_sport_nginx   latest                 267a1d054046        22 hours ago        16.1MB
composer             1.8.5                  78e8c9802c21        4 days ago          161MB
nginx                1.15.8-alpine          b411e34b4606        4 months ago        16.1MB
php                  7.2.13-fpm-alpine3.8   262e46e3d43c        5 months ago        77.7MB

$ docker ps
CONTAINER ID        IMAGE                COMMAND                  CREATED             STATUS              PORTS                  NAMES
b0faa127f7d4        docker_sport_nginx   "nginx -g 'daemon of…"   22 hours ago        Up 22 hours         0.0.0.0:1080->80/tcp   docker_sport_nginx_1
f929370e4a0e        docker_sport_php     "docker-php-entrypoi…"   22 hours ago        Up 22 hours         9000/tcp               docker_sport_php_1

$ docker exec -it docker_sport_nginx_1 ls -l public
-rw-r--r--    1 root     root           798 May 16 07:50 index.php

$ docker exec -it docker_sport_php_1 ls -la
-rw-r--r--    1 root     root           279 May 16 09:10 .env
drwxr-xr-x    2 root     root          4096 May 16 07:50 bin
-rw-r--r--    1 root     root          1443 May 16 08:10 composer.json
-rw-r--r--    1 root     root        118858 May 16 08:10 composer.lock
drwxr-xr-x    4 root     root          4096 May 17 07:00 config
drwxr-xr-x    4 root     root          4096 Jun  4 20:32 docker
drwxr-xr-x    2 root     root          4096 May 16 07:50 public
drwxr-xr-x    8 root     root          4096 May 17 07:00 src
-rw-r--r--    1 root     root          5998 May 16 08:10 symfony.lock
drwxrwxrwx    4 root     root          4096 Jun  4 20:33 var
drwxr-xr-x   11 root     root          4096 Jun  4 20:32 vendor

If you run $ curl -i 0.0.0.0:1080 command in terminal, the application should work.