Creating docker images at runtime and updating components


I have a very specific general Question about docker.

I want to compile a docker image at runtime. The docker image would consist of a configuration layer and an application layer.

| Configuration Files | <- This are user configurated files
| Application         | <- This is a layer that should be updatable
| Docker OS                | <- This is a layer that should be exchangable

There should be the possibility to modify existing images. But heres the clue: there is a layer of user configuration which should be on top of the application layer, which would be reused.
-> Load docker image
-> Exchange application layer
-> Compile into a new image.

Is this already possible with the docker technology? Do you even understand what I want to express?

Yours sincerly

pushing this topic