If you provision your app using a Dockerfile, you get a bunch of cool stuff because it knows what's been applied and what isn't.
If you provision your app using ansible, you get a bunch of cool provisioning features from ansible.
I want both. It looks like you provision your app using ansible, meaning that you're missing out on a some cool Docker features. Our ansible scripts take over a minute to run even when it doesn't make any changes but one of the major reasons to use docker is because you can spin up an instance instantaneously.