Quick symfony 4 sandbox with docker

So you want to play with the new version of symfony ? Docker will be a powerful tool to help us setting up a sandbox for our symfony 4 experiments.

We will use the docker engine and docker-compose tool.

The stack :

• 1 built container based on official docker hub PHP image
• 1 container of mysql official image
• 1 container of adminer official image (a lightweight phpMyAdmin)

We will also use composer official image to initialize the project and install additional PHP packages.

To stay really simple we use the PHP built-in webserver

Create the following directory structure : two empty files docker-compose.yml and docker/app/Dockerfile

.
├── docker
│   └── app
│       └── Dockerfile
└── docker-compose.yml

App Dockerfile

As I said earlier we don’t need to install Apache or nginx we only need PHP cli because we will use the built in PHP webserver. We just install a few PHP extensions and tweak opcache according to symfony performance documentation

Now the stack

Not much to say about the db and adminer services. For the app service : we are building the image from our previous Dockerfile, two important things to notice :

• We override the CMD with PHP built-in webserver (-S option) who is listening on port 8000 inside our container it will serve the content of the /var/www/public directory, this will be our ./app/public outside the container : this directory does not exist yet, we will create symfony app skelton in next section.
• We set an environment variable that will be read by our symfony app to get the connection to the database. Notice that the login:pass in the connection string (i.e. root:mdp4db) is set indose the mysql container (also with an environment variable MYSQL_ROOT_PASSWORD: mdp4db)

Create the skelton of our symfony 4 app

docker run --rm --interactive --tty --volume $PWD:/app --user $(id -u):$(id -g) composer create-project symfony/website-skeleton app

This is basically equivalent of the command shown in symfony installation doc (i.e. composer create-project symfony/website-skeleton app) except that composer command is running inside a container. The result is that you now have an “app/” directory with a symfony 4 app skelton

Now just launch the stack with

docker-compose up -d

Check the attributed port with

$ docker-compose ps
       Name                     Command               State            Ports
-------------------------------------------------------------------------------------
symfony4_adminer_1   entrypoint.sh docker-php-e ...   Up      0.0.0.0:32794->8080/tcp
symfony4_app_1       docker-php-entrypoint php  ...   Up      0.0.0.0:32793->8000/tcp
symfony4_db_1        docker-entrypoint.sh mysqld      Up      3306/tcp

Here it’s 32794, so I can visit http://localhost:32794

You will have a 404 error because there is no routes defined yet. You can start playing with symfony 4 here : https://symfony.com/doc/current/page_creation.html

NB : if you want to install extra packages/ symfony flex recipes … you can do something like this (this is for installing admin flex package) :

docker run --rm --interactive --tty --volume $PWD/app:/app --user $(id -u):$(id -g) composer require admin

If you want to launch bin/console commands you can do things like :

docker-compose exec app bin/console doctrine:database:create
docker-compose exec app bin/console make:entity Film
docker-compose exec app bin/console doctrine:migrations:diff
docker-compose exec app bin/console doctrine:migrations:migrate
docker-compose exec app bin/console doctrine:query:sql 'SELECT * FROM film'

Enjoy !