Right now I have one Cosmos DB that have three different containers, therefore I use three different functions that are listening for Change Feed events from this Cosmos DB.
In the future amount of my containers will be grown from 3 to 100.
So, is it possible to have one function that will be listening for all changes in all containers and that can detect from what container changes have come?
The recommended pattern with Cosmos DB is to have a single or few data containers and partition data logically via property values, rather than segmenting into many containers. If at all possible, for change feed and other reasons, it would be worthwhile to review the proposed design to see if there is a way to consolidate containers and avoid this pain.
That said, if an unknown and growing number of containers must be supported, one way that might be achieved dynamically is with the Change Feed Processor via the SDK. When instantiating a processor instance using GetChangeFeedProcessorBuilder, you can provide the container name as a parameter. Given a configured or discovered list of all target containers, multiple change feed processor instances could be created and run in parallel.
This could be hosted in multiple ways. Consider using an ASP.NET Core app with an IHostedService, and avoiding Azure Functions in this case.