Hot reload of allow-list

[andrewzwaniga]

I am maintaining an allow-list of subscribers using the --subscriber-whitelist command when running Comet as a daemon process. Currently, the only solution I know of for periodically updating this allow-list is to stop Comet and restart it with modified --subscriber-whitelist arguments -- but maybe I am not aware of a more elegant solution.

If none exists, it would be nice to have a command line option e.g. --hot-reload that will allow for periodic refreshing of the broker's allow-list. For example, reading in a list of IP address from a user-supplied text file or through an environment variable e.g. SUBSCRIBER_WHITELIST. Perhaps the --hot-reload can be supplemented with a timer for how often this happens. I appreciate that a reload could interfere with broadcasting events to subscribers.

From my understanding of how Comet works, naively I expect this is a tricky request. Perhaps an asynchronous task could periodically check some file or environment variable for the the allow-list and then pass it to Comet.

I am open to discuss and brainstorm this further. It would be a very useful feature for my broker since its allow-list is expanding all the time and my current restart protocol seems overly disruptive.