This is cool, but probably the biggest appeal of docker to me is never having to use puppet again.

Although I used puppet in my example to run and manage docker containers, you don't have to. ;)

Here's the raw run command with the environment parameters passed in:

docker run -e SETTINGS_FLAVOR=prod -e AWS_ACCESS_KEY_ID=$aws_access_key -e AWS_SECRET_KEY=$aws_secret_key -e S3_BUCKET=$s3_bucket -e WORKER_SECRET_KEY=$worker_key -p 5000:5000 -m 0 samalba/docker-registry

Just slap that badboy in your favorite supervisory process manager (or even just run it) and you're good to go.

What configuration management tool are you using instead of puppet?