Running an application in Heroku means that most of the configuration is based on environment variables.
The following sed snippet is useful for getting the Heroku environment quickly transformed into calls to export which can be used in a local shell:
heroku config | sed -e 's/: */=/; s/^/export /; 1d'
Note that heroku config has further parameters which might fit better to your particular case, e.g. -s produces a very similar result and -j might be interesting as well.