How do I use an .env file with Docker Compose?

How do I use an .env file with Docker Compose?

You can use an .env file to define environment variables for your Docker Compose services. Just create a file named .env in the same directory as your docker-compose.yml file.

What should I include in the .env file?

In the .env file, you can define key-value pairs for your environment variables, like DATABASE_URL=postgres://user:pass@db:5432/mydb.

How do I reference these variables in my docker-compose.yml?

You can reference the variables in your docker-compose.yml using the syntax ${VARIABLE_NAME}. For example, you can set an environment variable like this: environment: - DATABASE_URL=${DATABASE_URL}.

Can I use default values for these variables?

Yes, you can set default values in your docker-compose.yml by using the syntax ${VARIABLE_NAME:-default_value}. This way, if the variable is not set in the .env file, it will use the default value.