How do I pass environment variables to Docker containers when running them?

Exactly! I’ve been in situations where flexibility was key, and using environment variables in Docker containers is the best way to go. Instead of hardcoding sensitive info, I pass environment variables during the docker run using the --env or -e flag, like so:

docker run --env DB_CONN="db_connection_string" myapp

This way, you don’t have to reconfigure your Dockerfile. And if you’ve got several variables to handle, it’s even better to use an env file with --env-file. That method keeps everything neat and secure by managing sensitive information outside the image itself.