Seems event.headers['client-ip'] has started to be undefined some time this week. I still could not find any documentation on X-Nf-Client-Connection-Ip via Google, but fortunately this thread appeared.On the other hand, event.headers['X-Nf-Client-Connection-Ip'] is also undefined for me right now, so not sure how to proceed…
Update: Seems using lowercase event.headers['x-nf-client-connection-ip'] works for now.
Update 2: Ths smells related, although of course it should not touch any of this: Upcoming change: Stripping exposed Netlify headers from function and proxy requests