UP, // Ready to receive traffic
DOWN, // Do not send traffic- healthcheck callback failed
STARTING, // Just about starting- initializations to be done - do not
// send traffic
OUT_OF_SERVICE, // Intentionally shutdown for traffic
UNKNOWN;

This could be useful to start instances with OUT_OF_SERVICE then changing it to UP after testing.

Comment From: heowc

I think this feature would be useful. Is there anything in progress regarding this?

(It was done a few years ago and then canceled, but I don't think it's been done since.)

Or is it something that already exists but I just can't find it? 🤣