How can I share secret environment variables in a shared configuration?

Hello,

I have a docker-compose shared configuration which is committed to git, and now I need it to include environment variables that are secret and don't need to be committed.

For example, add S3 credentials to one of the docker-compose services as environment variables.
As the author of the configuration I want my team to have the service configured with these environment variables, but I don't want the credentials to be committed along with the configuration XML.

Is this something that can be done?