bunyan -o short from Environment Variable

[johnico]

I have a docker image that builds the node app and run the app in production
then all logs printed to the stdout ( docker logs)

in dev mode I added "| bunyan -o short" and I see the logs as a nice text

but in production, I got only JSON format

how can I control the format via the code? and not cli usage
I would like to pass to the logger class an ENV param and then in the class decide which format to use