How to migrate from CF 4.1 iso to docker CF 4.2?

We would want to migrate from CF 4.1 to 4.2, and by the way, use docker instead of iso appliance.

In production env, our CF 4.1 is an iso appliance.

We have installed CF 4.2 docker version and want to migrate to it for best flexibility.

We want to keep all configurations : database, tags, ruby gems, integration code : everything we have customized.

Is there a procedure for that?

As we have docker MIQ labs too, is the procedure the same for MIQ migrations?