Getting Started With Docker

One of the most important things while working in a team is making sure that everyone runs the same stack, but also making sure it’s as close to production as possible.

Developing with Laravel is great and gives you a few options out of the box (Homestead & Valet), but there are other tools you can use. Valet just configures nginx to run on your machine and provides an easy CLI to manage the sites you’re developing on. Homestead is a pre-configured Vagrant configuration that includes a lot of different packages for you to use. Both options are great for begginers; but, in my opinion, they aren’t great for managing environments across teams or mimicing production environments.

Why Docker?

• Docker runs on macOS, Linux, and Windows.
• It ensures that all team members have the same reproducible environment.
• Set-up time is minimal for new hires.
• Doesn’t require any of your stack to be installed locally.

Getting Started

We’re going to be using Docker Compose, this is a tool for defining and running multi-container applications. Why multi-container? Each of our services should be independent! In the real world with scaling, you don’t have multiple large boxes all running the same things. For example, your database may be an AWS RDS instance, which is completely seperate from your nginx/apache instances.

For our example application, we’re going to be using nginx, php-fpm, mysql and mailhog.

We need to start by creating our compose file, so in your project root, create a new file called docker-compose.yml. In here, we’re going to define our containers. My compose file has 5 services, mysql, php-fpm, webserver, artisan, queue-worker.

version: "3.1"

services: 
  
    mysql:
        image: mysql:5.7
        container_name: myapp-mysql
        working_dir: /application
        ports:
            - "3306:3306"
        environment:
            - MYSQL_ROOT_PASSWORD=password
            - MYSQL_DATABASE=myapp
            - MYSQL_USER=myuser
            - MYSQL_PASSWORD=password
    
    webserver:
        build:
            context: .
            dockerfile: docker/nginx/Dockerfile
        container_name: myapp-webserver
        hostname: api.myapp.test
        working_dir: /application
        volumes:
            - .:/application:cached
            - ./docker/nginx/nginx.conf:/etc/nginx/conf.d/default.conf
        ports:
            - "80:80"
            - "443:443"
        links:
            - php-fpm
    
    php-fpm:
        build:
            context: .
            dockerfile: docker/php-fpm/Dockerfile
        container_name: myapp-php-fpm
        working_dir: /application
        volumes:
            - .:/application:cached
            - ./docker/php-fpm/php-ini-overrides.ini:/etc/php/7.2/fpm/conf.d/99-overrides.ini
        links:
            - mysql
    
    artisan:
        build:
            context: .
            dockerfile: docker/artisan/Dockerfile
        container_name: myapp-artisan
        working_dir: /application
        volumes:
            - .:/application:cached
        links:
            - mysql
    
    queue-worker:
        build:
            context: .
            dockerfile: docker/artisan/Dockerfile
        container_name: enterprise-worker
        working_dir: /application
        volumes:
            - .:/application
        entrypoint: php artisan queue:work --tries=3
        links:
            - mysql

As you can see here, there’s a couple of different things going on in some of the containers. some of them have image and others have build! Image just means that we are using a pre-built docker image that’s been published to docker hub. build means that we’re taking a local docker file and building it ourselves.

One of the important things in here is links, this enables containers to talk to each other.

php-fpm container

From your application root directory, create a folder called docker, then one inside of it called php-fpm.

mkdir -p docker/php-fpm

Inside of here, create a Dockerfile, mine looks like this:

FROM php:7.2-fpm

RUN apt-get update \
    && apt-get install -y gnupg libcurl4-openssl-dev sudo git libxslt-dev zlib1g-dev graphviz zip libmcrypt-dev \
      libicu-dev g++ libpcre3-dev libgd-dev libfreetype6-dev sqlite curl build-essential unzip gcc make autoconf \
      libc-dev pkg-config ruby git zlib1g-dev libfreetype6-dev libjpeg62-turbo-dev libpng-dev libxpm-dev libvpx-dev \
      netcat libmagickwand-dev libxml2-dev \
    && apt-get clean \
    && docker-php-ext-configure gd \
            --with-freetype-dir=/usr/lib/x86_64-linux-gnu/ \
            --with-jpeg-dir=/usr/lib/x86_64-linux-gnu/ \
            --with-xpm-dir=/usr/lib/x86_64-linux-gnu/ \
            --with-vpx-dir=/usr/lib/x86_64-linux-gnu/ \
    && docker-php-ext-install zip mbstring gettext curl pdo_mysql json intl gd soap \
    && pecl install imagick xdebug \
    && docker-php-ext-enable imagick xdebug

WORKDIR "/application"

This means we’re using the php image (tagged with 7.2-fpm) as a base, then running commands like you would in your terminal. Here we’re just installing some extensions such as gd, soap, pdo_mysql etc.

Take a second look at the compose file and notice that there is two items in volumes. One mounts our local application into /application and uses caching to speed things up. The second one takes ./docker/php-fpm/php-ini-overrides.ini and places it in /etc/php/7.2/fpm/conf.d/99-overrides.ini. This allows us to override default settings in the php-fpm container. If you’re happy with the defaults, remove this line from the compose file.

Artisan container

The artisan dockerfile looks like this:

FROM vcarreira/php7:latest

ENTRYPOINT ["php", "artisan"]
CMD ["list"]

this is currently a WIP and needs to be refactored to use official PHP images!

This image is used by the artisan container and also the queue worker. The queue worker has a different entrypoint in the docker-compose.yml, this makes the container automatically run php artisan queue:work --tries=3 instead of php artisan list.

nginx container

The dockerfile for the nginx container is this:

FROM nginx:alpine

RUN apk update && apk upgrade && \
    apk add --no-cache bash git openssh

It just uses the default nginx image, but we add in some other things to make our debugging easier.

As per the docker-compose.yml, we have something in the volumes, just like the php-fpm container. This creates our nginx.conf file. Here is a very basic nginx.conf you can use.

server {
    listen 80 default_server;
    server_name api.myapp.test;
    root /application/public;
    index index.php;
    if (!-e $request_filename) {
        rewrite ^.*$ /index.php last;
    }

    location ~ \.php$ {
        fastcgi_pass php-fpm:9000;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PHP_VALUE "error_log=/var/log/nginx/application_php_errors.log";
        fastcgi_buffers 16 16k;
        fastcgi_buffer_size 32k;
        include fastcgi_params;
    }
}

You can see in here that for the fastcgi_pass, we have php-fpm:9000. The docker container will resolve this to an internal IP that is given to your php-fpm container when it is created.

Running compose

The final step to all of this is running it. All we need to do is build the containers that aren’t pre-made and pull the pre-made ones!.

docker-compose pull && docker-compose build

This will take a few minutes as it downloads the containers and then builds your custom ones. While this is running, set up dnsmasq (or edit your hosts file) to make sure your local test domain is pointing to 127.0.0.1.

Once pull and build have finished running, it’s time to bring up the containers!

docker-compose up will bring them all up and show logs/output from each one in the terminal window that you run it from.

docker-compose up -d will bring them up, but background the process. You can use docker-compose logs to view the logs from the containers.

Open up your browser and go to api.myapp.test and you’ll be presented with your application.