Proposed change

Include a more streamlined way to add additional events manually in functions like hooks or other overloaded functions. Some of these functions might have code running that fails/succeeds in ways that might be relevant for the user and there currently is no easy way to emit these messages.

Alternative options

The current alternative would be manually creating K8s events from the code, so they get picked up again by the events property and then yielded by the progress property.

Who would use this feature?

Any setup that modifies the pods or has additional steps before spawning could benefit from giving additional information to the user in a streamlined way. As an example, in our setup, the image repository (harbor) scans user-built (binderhub) images for vulnerabilities and only then gives them up for pulling. This feature would make it simpler to inform the user of what's going on, or what went wrong (if the image were to be flagged as vulnerable).

(Optional): Suggest a solution

Add a way of including messages in the format of what is yielded in ´progress´ that you can emit easily from within the spawner code using a spawner method (e.g. emit_message or similar).

I can create a PR for this myself, I just wanted to see if there is any interest in this feature first.