Set environment variables in local development with Docker

How to set environment variables and configure .env file locally with Docker

Step 1

Create the .env file in the folder where the docker-compose.yaml file is located.

Step 2

Inside the .env file add the value to the variable that you want to use, for example:

Step 3

Define in the docker-compose.yaml at the environment section one variable through which to reference the variable set in .env, for example DENIS_TEST: ${KAFKA_PORT_NUMBER} in my case. Also, you must to add the .env file name at env_file like this env_file: .env. Please take into account the indentation at env_file: .env, as in the image below:

Step 4

Add in the wp-config.php file the define line with the environment variable that you want to use and after that, you write an error_log line for log the value of the variable. See below the content of the wp-config.php file:

Step 5

Go inside of your website repository and run docker compose up command.

Visit the http://localhost:8080/wp-login.php for login into the local website.

After that, check the logs for the value of the setted variable.

DONE!