Just a minor point for other people reading, not for @mpalmer who knows all this stuff 
. Nothing gets configured on container “start”, only on container “create”.
So, for example,
./launcher stop app
./launcher start app
Will not change anything in the environment.
Stuff gets configured on container creation, which means that there needs to be no pre-existing container on the machine when you run start
There are indeed ways of using ENV to bootstrap bits of hardcoded data in the container image. However we really should prefer params here.
I always found this distinction to be just way to subtle for people to comprehend which is why I always ask people to do ./launcher rebuild and forget about all the nuance and edge caseyness here.