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/Configuration: Environment Variables
Configuration: Environment Variables
Learn to change the Bitnami WordPress image such that it reads the configuration from environment variables.
In this lesson, we’ll detach the configuration from the instance, following the third principle of the twelve-factor app to store configuration in the environment. To do this, we will use environment variables similar to how we store the AWS credentials for the Educative terminal.
To do so, we’ll prepare a WordPress image to read environment variables through its configuration file. In the next lesson, we’ll prepare the EC2 user data script to set these environment variables externally.
Configuration variables to consider
First, we need to know which environment variables we want to set.
The most important configuration variables for WordPress that we need to manage are the following:
DB_HOSTDB_PASSWORDDB_NAMEDB_USER
If we want to separate the database from the WordPress instance, we need to be able to set these independent of the EC2 instance. So these should go into the EC2 user data.
There is only one problem—WordPress doesn’t know how to read environment variables by default.
Install a library to read ENV variables in PHP
WordPress is using PHP and is running as a daemon in the background. Unfortunately, this also means it won’t directly see the environment variables we set in the EC2 user data script.
Instead, we will use an alternative method to set environment variables for an application running as a service. The idea is to create a .env file that contains all the ...