I have a scenario, where new function apps are being create every week and need to (automatically) proxy them form main function app.
I could not find any way to "just" updated proxies.json without re-deploying entire function app. Any CLI Command / Rest API reference to just update proxies file ?
what you need to do is to use continuous deployment.
You need to first have some repos like github repo. continuous deployment also called incremental deployment. It is specifically designed for the situation that you mentioned.