How can I use Docker Compose to manage environment variables?

How can I use Docker Compose to manage environment variables?

You can define environment variables in your docker-compose.yml file using the environment key. Would you like an example?

Yes, please provide an example of how to set environment variables.

Sure! Here's a simple example:

version: '3'
services:
  app:
    image: myapp
    environment:
      - NODE_ENV=production
      - API_KEY=${API_KEY}

In this example, NODE_ENV is set directly, while API_KEY is pulled from your host's environment.

Can I use a .env file to manage these variables?

Absolutely! You can create a .env file and define your variables there. Docker Compose will automatically use them. For example:

API_KEY=your_api_key_here

Then in your docker-compose.yml, you can reference them as shown earlier.