Setting by env variable

I would like to set some setting parameter (such as S3 parameter) by using env variable instead of GUI, is it possible and where I can find the name of the ENV for this ?

Piece of cake.

Simply take any of the settings that you can see, capitalise it to keep things consistent, add DISCOURSE to it, and link it all up with _'s (underscores).

You then put this in app.yml before the volumes: section, indenting it exactly (usually with 2 spaces) as the other environmental settings in there.

For example: