Today my River4 server started having problems updating new feeds. I vaguely recall encountering the issue before and resolving it, but rather than that I decided to switch to River5. 

Here is where using Docker comes in handy because it makes it easy for me to retain my current River4 container so I can easily switch back to it, while starting a new container with River5. 

While I built the River4 Docker image that I my container runs, someone else already made a River5 image that is available on Docker Hub to be pulled. 

The developer of the River5 image separated the configuration components from the data by creating separate volumes for each. He states that you can map the config volume to your local server, but doesn't provide any details. It turns out that you do need to create a lists subdirectory for storing subscription list files.  If you wanted to see the data that River5 generates you could map a local server folder to the data volume, but under normal operations you shouldn't need to see the data files.

What would be helpful is a way to replace the default config.json file with your own copy of config.json but according to the docs, this file needs to be in the same directory as river5.js, which means mapping a local server directory to the directory in the container in which river5.js is stored and I don't know what problems that may cause. 

All this being said, I am now running River5 and could pretty easily switch back to River4 should I need to.