Database, cache, and other storage connection information.These changes are independent of code changes, so they do not require your application to be rebuilt to change.ĭata which changes depending on the environment your app is running on should be set as environment variables. By relying on external configurations, your app can easily be deployed on different environments. Typically, our applications require many variables to be set in order for them to work.

Why use Environment Variables?Įnvironment variables are excellent for decoupling application configurations.

If you open the terminal or command line application in Linux, Mac OS, or Windows and enter set, you will see a list of all environment variables for your user. An environment variable is simply a name mapped to a value.īy convention, the name is capitalized e.g. They're mutable and can vary - hence the name variables.Įnvironment variables are variables external to our application which reside in the OS or the container of the app is running in. What are Environment Variables?įrom programming we know that variables are stored values that can be changed. To better manage them we can use the dotenv library, which allows us to load environment variables from a file. Large applications tend to have many environment variables. Separating configurations make it easier for our application to be deployed in different environments. We need to ensure each environment is configured correctly, it could be disastrous if our production application was using our development database, for example.Įnvironment variables allow us to manage the configuration of our applications separate from our codebase. Many apps are deployed in a development environment before being deployed to the production environment. Deploying an application requires developers to put thought and consideration into how it is configured.

Mac os list environment variables