Last updated February 27, 2019

One of the problems with Dockerizing an existing project is that configuration information tends to proliferate everywhere. Not only do we have settings in docker-compose.yml, but also in our Docker-specific settings file settings.docker.php. If we change a setting in one place we need to copy and paste it everywhere else. This can make things difficult if we suddenly have the need to change a setting.

Fortunately, there's a way to centralize Docker configuration for our project by using an environment file.

In this tutorial, we'll:

  • Review what an environment file is and its format.
  • List the advantages of moving Docker configuration to an environment file.
  • Describe the .env file, and how it provides us further advantages.