Should we only care about the last condition? If so, do we need to remove this part?

No, it's necessary to iterate through all the conditions because the reason may be in any of them.

Will it be a stale condition?

it will not be a stale condition. Kubernetes regularly updates Pod conditions, so if a condition with the corresponding reason is found, it is assumed to be current. If a stale condition were detected, that would indicate an issue in Kubernetes, not in this logic.

Will a pod have multiple different reasons?

Yes, a Pod can have different “Reasons” throughout its lifecycle. Each event or change in the Pod’s state (for example, container creation, image pulling, runtime errors, restarts, etc.) can trigger a different reason. In Kubernetes, these “Reasons” are recorded at different points in the Pod’s lifecycle, so it is entirely possible for a single Pod to go through multiple different “Reasons” as it transitions between states.

Yes, I was thinking the case where the pod status is failed to image, then runtime errors, then restart.

Will the above metric have all of these three status?

Yes, if your Pod transitions through those states (e.g., failed to pull image, runtime errors, then restarts), the metric can capture each corresponding reason at the time it occurs. However, you won’t necessarily see all reasons simultaneously; rather, you’ll see them reflected as changes in the metric over the Pod’s lifecycle.