Push status updates as soon as readiness state changes for containers,
rather than waiting for the sync loop to update the status. In
particular, this should help new containers to come online faster.
Additionally, consolidates prober test helpers into a single file.
- PeriodSeconds - How often to probe
- SuccessThreshold - Number of successful probes to go from failure to success state
- FailureThreshold - Number of failing probes to go from success to failure state
This commit includes to changes in behavior:
1. InitialDelaySeconds now defaults to 10 seconds, rather than the
kubelet sync interval (although that also defaults to 10 seconds).
2. Prober only retries on probe error, not failure. To compensate, the
default FailureThreshold is set to the maxRetries, 3.
- status.Manager always deals with the local (static) pod, but gets the
mirror pod when syncing
- This lets components like the probe workers ignore mirror pods
This commit builds on previous work and creates an independent
worker for every liveness probe. Liveness probes behave largely the same
as readiness probes, so much of the code is shared by introducing a
probeType paramater to distinguish the type when it matters. The
circular dependency between the runtime and the prober is broken by
exposing a shared liveness ResultsManager, owned by the
kubelet. Finally, an Updates channel is introduced to the ResultsManager
so the kubelet can react to unhealthy containers immediately.
Change all references to the container ID in pkg/kubelet/... to the
strong type defined in pkg/kubelet/container: ContainerID
The motivation for this change is to make the format of the ID
unambiguous, specifically whether or not it includes the runtime
prefix (e.g. "docker://").
Each container with a readiness has an individual go-routine which
handles periodic probing for that container. The results are cached, and
written to the status.Manager in the pod sync path.
