Feature: whitelist nodes (a new mode)

[msadowski]

Hi!

I've been wondering for a while about a potential new feature of whitelisting nodes. The way I see this is there is an option to neglect the nodes right now.

What I'm proposing is to add an option to whitelist nodes using pattern matching (so it's kind of a reverse of neglecting nodes). That way if you have a particular set of topics that you are interested in in your system then instead of excluding almost all topics you can include a handful you are interested in.

The way I would implement it is that if whitelist is not specified then the node_alive_server should work as it currently does, if however there is any string parameter to be whitelisted then only nodes matching the string should be monitored.

Please let me know if that's something you would be interested in.