Easiest way to have a 100% copy of a Cosmos DB container

Author: Niels Brinch

Originally Sourced from: https://stackoverflow.com/questions/64351878/easiest-way-to-have-a-100-copy-of-a-cosmos-db-container

I want two different containers in my Cosmos DB database to contain the exact same data all the time. The only difference will be the partition key of the container.

What is the easiest way to accomplish this? I am looking for a method with none to little code so I do not like the Data Factory solution that the internet seems to recommend. Perhaps there is another service in Azure or a third party service - or maybe it can be done robustly with simple triggers?

EDIT: Clarification - I need them to be continuously updated. One container is where all the data is changed during normal use and the other container should be kept synchronized as it happens.