This document is part of the Appwrite contributors' guide. Before you continue reading this document, make sure you have read the Code of Conduct and the Contributing Guide.
Adding new features may require various configuration options to be set by the users. And for such options, we use environment variables in Appwrite.
This tutorial will cover how to properly add a new environment variable in Appwrite.
The environment variables in Appwrite are prefixed with _APP_. If it belongs to a specific category, the category name is appended as _APP_REDIS for the Redis category. The available categories are General, Redis, MariaDB, SMTP, Storage, Functions and Maintenance. Finally, a properly describing name is given to the variable. For example, _APP_REDIS_HOST is an environment variable for the hostname of your Redis instance. You can find more information on available categories and existing environment variables in the environment variables doc.
First of all, we add the new environment variable to app/config/variables.php in the designated category. If none of the categories fit, add it to the General category. Copy the existing variable description to create a new one so that you will not miss any required fields.
This information is also used to generate the website documentation at https://appwrite.io/docs/environment-variables, so please use good descriptions that clearly define the purpose and other required info about the environment variable that you are adding.
If the newly introduced environment variable has a default value, add it to the .env and Dockerfile along with other environment variables. .env file uses settings for Appwrite development environment.
Add the new environment variables to the docker-compose.yml and app/views/install/compose.phtml for each docker service that requires access to those environment variables.
The docker-compose.yml file is used by the Appwrite maintainers during development, whereas the app/views/install/compose.phtml file is used by the Appwrite setup script.
With these steps, your environment variable is properly added and can be accessed inside Appwrite code and any other containers where it is passed. You can access and use those variables to implement the features you are trying to achieve.
If everything went well, commit and initiate a PR and wait for the Appwrite team's approval.
Whooho! You have successfully added a new environment variable to Appwrite. 🎉