Hi @lis. It is a very interesting question, let me try to explain to you why we need different containers to run rasa server and rasa action server.
As you are aware the rasa server is running on port 5005 and the rasa action server is running on 5055 ( you can expose any mention port in your docker file or docker-compose file).
Docker is an open source containerization platform. It enables developers to package applications into containers —standardized executable components combining application source code with the operating system (OS) libraries and dependencies required to run that code in any environment.
It is generally recommended that you separate areas of concern by using one service per container . That service may fork into multiple processes. The container’s main process is responsible for managing all processes that it starts. Further, Isolation: By placing each process in a separate container, you gain the benefits of isolating the process so that it can’t interfere with others. Easier to scale : When a container consists of just one single process, it is easier to scale the application by creating more instances of the container.
If you are using the custom action then you required a action server container else you required only rasa server.
For Rasa open source deployment on docker, you can ref this thread: Dockerizing my rasa chatbot application that has botfront - #11 by nik202
I hope this will give you better understanding and solve your issue. Goodd Luck!