We run only a small handful of instances on Google Cloud Platform and we don't run them all the time. Generally we just fire one up, do what we need to do then shut it down... which is great, except when "we" forget to shut them down.
I've been able to track down the relevant REST APIs and the gcloud sdk but I don't see anything that says who started the instance. Actually it also doesn't have a timestamp on when it was started.
I did find this python app engine script that I might be able to rewrite to stop the instances after X amount of time, but I'd rather find a way to notify the user who started it and let them know the instance is still running.
Has anyone tried to do something similar or seen a way to get the "starter" of the instance in GCP?