The formatting function is used often in logging. This improves the readability
by shortening the length of the call. Also change the fomartted string to
include the pod UID.
Before this change we have a mish-mash of ways to pass field names around for
error generation. Sometimes string fieldnames, sometimes .Prefix(), sometimes
neither, often wrong names or not indexed when it should be.
Instead of that mess, this is part one of a couple of commits that will make it
more strongly typed and hopefully encourage correct behavior. At least you
will have to think about field names, which is better than nothing.
It turned out to be really hard to do this incrementally.
if LowThresholdPercent > HighThresholdPercent, amountToFree at image_manager.go:208 is negative and image GC will not free memory properly.
Justification:
1) LowThresholdPercent > HighThresholdPercent implies (LowThresholdPercent * capacity / 100) > (HighThresholdPercent * capacity / 100)
2) usage is at least (HighThresholdPercent * capacity / 100)
3) amountToFree = usage - (LowThresholdPercent * capacity / 100)
Combining 1), 2) and 3) implies amountToFree can be negative.
What happens if amountToFree is negative? in freeSpace method, "for _, image := range images " loops at least once
and if everything goes fine, "delete(im.imageRecords, image.id)" is executed.
When checking for condition "if spaceFreed >= bytesToFree", it is always true as bytesToFree is negative
and spaceFreed is positive. The loop is finished, so is image GC.
At the end, only the oldest image is deleted. In situations where there is a lot of dead containers,
each container corresponing to distinct image, number of unused images can get higher.
If two new images get pulled in every 5 minutes, image GC will not work properly and will not free enough space.
Secondly, it will take a lot of time to free all unused images (hours depending on a number of unused images).
This is an incorrect configuration. Image GC should report it and refuse to work.
All external types that are not int64 are now marked as int32,
including
IntOrString. Prober is now int32 (43 years should be enough of an initial
probe time for anyone).
Did not change the metadata fields for now.
Addresses a version skew issue where the last condition status is always
evaluated as the NodeReady status. As a workaround force the NodeReady
condition to be the last in the list of node conditions.
ref: https://github.com/kubernetes/kubernetes/issues/16961
