Database Setup & Docker

All right, we have Doctrine installed! But now we need, ya know, to get a database server running.

DATABASE_URL Environment Variable

Take a look at our .env file. When we installed Doctrine, the Flex recipe added this doctrine-bundle section. The DATABASE_URL environment variable is where we tell Doctrine how to connect to our database. It's a special URL-looking string called a DSN, if you want some nerdy terminology.

It holds the type of database we're connecting to - mysql, postgres, sqlite, borgsql, etc, a username, password, host, port, and the database name. Any query params are extra config.

By default, the DATABASE_URL is set to connect to a Postgres database and that's what we'll use. We'll get it running super easily with Docker.

If you don't want to use Docker, no problem! Comment out this line and uncomment the sqlite one. SQLite doesn't require a server: it's just a file on your filesystem. Because Doctrine abstracts the database layer, for the most part, the code we write will work with any database type. Cool!

Remember, don't store any sensitive info in this file: it's committed to your repo. If you have your own database server locally, create a .env.local file (this is ignored by Git), and set your own DATABASE_URL there.

Starting a Postgres Container with Docker

Ok, so how can we get a Postgres database server running?

Take a look at compose.yaml. This was added by a Flex recipe and holds Docker config, including this database service to spin up a Postgres container. Fantastic! You can do whatever you want, but we are only going to use Docker as a convenient way to run a database server locally. PHP itself is installed normally on my machine.

Open your terminal and run:

docker compose up -d

This start the Docker containers and -d tells Docker to do it all in the background.

But where is the database server running? Like what port? Don't we need to know so we can update DATABASE_URL to point to it?

The Symfony CLI is Awesome!

No! The symfony CLI binary that's running the web server has some Docker magic! Jump over and refresh the app. Down here, hover over "Server". This holds details about the Symfony CLI server. This part means that it automatically detected our docker containers and set up the environment variables for us!

I'll show you. Pop over to our terminal and run:

symfony var:export --multiline

This shows us some extra environment variables that the Symfony CLI is setting for us, in addition to the ones in .env.

Scroll up a bit to see.... Ah! Here it is! DATABASE_URL! This overrides the one in .env and points to the Postgres database running in Docker. That port number will randomly change, but the Symfony CLI will always use the correct one.

symfony console vs bin/console

Now, we're used to running Symfony commands with bin/console. But when using the Symfony CLI with a Docker database, we need to run the database-specific commands through symfony console instead. It's the same as bin/console, but it gives the Symfony CLI a chance to add the environment variables.

Creating the Database

Ok! Database server running in a Docker container and DATABASE_URL is pointing to it. To create the database, run:

symfony console doctrine:database:create

An error?! No worries! The error is telling us the database already exists: apparently the server comes with one. But this is good, it means we are connecting to our database server!

Ok crew, we have Doctrine and a database. Now we need a table! We'll do that next by jump lifting off into the world of entities and migrations.