Track Executable and Container state changes

[dbreshears]

[dbreshears]

Similar to Docker Events.

[karolz-ms]

Kubernetes provides two main mechanisms for tracking object state changes:

1. Conditions for reporting latest observed status of an object e.g "running", "terminated" and so on. Objects can be in multiple "conditions" simultaneously.

2. Events (also see Events in API Conventions doc) store information about history of object state changes.

[karolz-ms]

Did some investigation and came to the conclusion that neither Kubernetes Events nor Kubernetes Conditions are suitable for tracking individual object state changes.

Events are cluster resource. They have separate query/subscription API from regular object and are only loosely coupled to regular objects.

Conditions are tightly coupled to objects, but they are not designed for tracking state changes; they only describe the current state of the object in an easy-to-consume way.

We need a type that carries data not unlike Kubernetes Event, but one that can be stored in a collection that is included in object Status data.