Lifecycle management with Docker?

Hello together,

first of all. Sorry for my bad english.
I’m new in Docker and i have a more fundamental Question about Lifecycle management with Docker.

I have a Application with the following components:

  • Nginx
  • gearmand
  • supervisord
  • Webapplication
  • Redis

up to this point very easy.
The enviroment is a test, preproduction an live system. Each with two machines behind a loadbalancer an autoscaling.
I will make a two Docker container. 1 for the Nginx + Webapp and 1 for the Redis on a different Server.

The current procedure is that I became a RPM from the development company and install it handicraft on the Testsystem.
After testing by Professionals it goes to Preprod and will test again by special customers. Now it will be installed on Live system.

I don’t understand how these procedure looks in a docker enviroment.
Do I need for each new RPM to change to Dockerfile and build the image new or do i have to install the rpm in the container and tag it as a new version. How do i have to roll out the tested container to preprod and later to livesystem?

Thank you for your help.

Kind Regards,