If a CRI error occurs during the terminating phase after a pod is
force deleted (API or static) then the housekeeping loop will not
deliver updates to the pod worker which prevents the pod's state
machine from progressing. The pod will remain in the terminating
phase but no further attempts to terminate or cleanup will occur
until the kubelet is restarted.
The pod worker now maintains a store of the pods state that it is
attempting to reconcile and uses that to resync unknown pods when
SyncKnownPods() is invoked, so that failures in sync methods for
unknown pods no longer hang forever.
The pod worker's store tracks desired updates and the last update
applied on podSyncStatuses. Each goroutine now synchronizes to
acquire the next work item, context, and whether the pod can start.
This synchronization moves the pending update to the stored last
update, which will ensure third parties accessing pod worker state
don't see updates before the pod worker begins synchronizing them.
As a consequence, the update channel becomes a simple notifier
(struct{}) so that SyncKnownPods can coordinate with the pod worker
to create a synthetic pending update for unknown pods (i.e. no one
besides the pod worker has data about those pods). Otherwise the
pending update info would be hidden inside the channel.
In order to properly track pending updates, we have to be very
careful not to mix RunningPods (which are calculated from the
container runtime and are missing all spec info) and config-
sourced pods. Update the pod worker to avoid using ToAPIPod()
and instead require the pod worker to directly use
update.Options.Pod or update.Options.RunningPod for the
correct methods. Add a new SyncTerminatingRuntimePod to prevent
accidental invocations of runtime only pod data.
Finally, fix SyncKnownPods to replay the last valid update for
undesired pods which drives the pod state machine towards
termination, and alter HandlePodCleanups to:
- terminate runtime pods that aren't known to the pod worker
- launch admitted pods that aren't known to the pod worker
Any started pods receive a replay until they reach the finished
state, and then are removed from the pod worker. When a desired
pod is detected as not being in the worker, the usual cause is
that the pod was deleted and recreated with the same UID (almost
always a static pod since API UID reuse is statistically
unlikely). This simplifies the previous restartable pod support.
We are careful to filter for active pods (those not already
terminal or those which have been previously rejected by
admission). We also force a refresh of the runtime cache to
ensure we don't see an older version of the state.
Future changes will allow other components that need to view the
pod worker's actual state (not the desired state the podManager
represents) to retrieve that info from the pod worker.
Several bugs in pod lifecycle have been undetectable at runtime
because the kubelet does not clearly describe the number of pods
in use. To better report, add the following metrics:
kubelet_desired_pods: Pods the pod manager sees
kubelet_active_pods: "Admitted" pods that gate new pods
kubelet_mirror_pods: Mirror pods the kubelet is tracking
kubelet_working_pods: Breakdown of pods from the last sync in
each phase, orphaned state, and static or not
kubelet_restarted_pods_total: A counter for pods that saw a
CREATE before the previous pod with the same UID was finished
kubelet_orphaned_runtime_pods_total: A counter for pods detected
at runtime that were not known to the kubelet. Will be
populated at Kubelet startup and should never be incremented
after.
Add a metric check to our e2e tests that verifies the values are
captured correctly during a serial test, and then verify them in
detail in unit tests.
Adds 23 series to the kubelet /metrics endpoint.
Add a node e2e to verify that if a static pod is terminated while the
container runtime or CRI returns an error, the pod is eventually
terminated successfully.
This test serves as a regression test for k8s.io/issue/113145 which
fixes an issue where force deleted pods may not be terminated if the
container runtime fails during a `syncTerminatingPod`.
To test this behavior, start a static pod, stop the container runtime,
and later start the container runtime. The static pod is expected to
eventually terminate successfully.
To start and stop the container runtime, we need to find the container
runtime systemd unit name. Introduce a util function
`findContainerRuntimeServiceName` which finds the unit name by getting
the pid of the container runtime from the existing
`ContainerRuntimeProcessName` flag passed into node e2e and using
systemd dbus `GetUnitNameByPID` function to convert the pid of the
container runtime to a unit name. Using the unit name, introduce helper
functions to start and stop the container runtime.
Signed-off-by: David Porter <david@porter.me>
The recently introduced failure handling in ExpectNoError depends on error
wrapping: if an error prefix gets added with `fmt.Errorf("foo: %v", err)`, then
ExpectNoError cannot detect that the root cause is an assertion failure and
then will add another useless "unexpected error" prefix and will not dump the
additional failure information (currently the backtrace inside the E2E
framework).
Instead of manually deciding on a case-by-case basis where %w is needed, all
error wrapping was updated automatically with
sed -i "s/fmt.Errorf\(.*\): '*\(%s\|%v\)'*\",\(.* err)\)/fmt.Errorf\1: %w\",\3/" $(git grep -l 'fmt.Errorf' test/e2e*)
This may be unnecessary in some cases, but it's not wrong.
The recently introduced failure handling in ExpectNoError depends on error
wrapping: if an error prefix gets added with `fmt.Errorf("foo: %v", err)`, then
ExpectNoError cannot detect that the root cause is an assertion failure and
then will add another useless "unexpected error" prefix and will not dump the
additional failure information (currently the backtrace inside the E2E
framework).
Instead of manually deciding on a case-by-case basis where %w is needed, all
error wrapping was updated automatically with
sed -i "s/fmt.Errorf\(.*\): '*\(%s\|%v\)'*\",\(.* err)\)/fmt.Errorf\1: %w\",\3/" $(git grep -l 'fmt.Errorf' test/e2e*)
This may be unnecessary in some cases, but it's not wrong.
All code must use the context from Ginkgo when doing API calls or polling for a
change, otherwise the code would not return immediately when the test gets
aborted.
Every ginkgo callback should return immediately when a timeout occurs or the
test run manually gets aborted with CTRL-C. To do that, they must take a ctx
parameter and pass it through to all code which might block.
This is a first automated step towards that: the additional parameter got added
with
sed -i 's/\(framework.ConformanceIt\|ginkgo.It\)\(.*\)func() {$/\1\2func(ctx context.Context) {/' \
$(git grep -l -e framework.ConformanceIt -e ginkgo.It )
$GOPATH/bin/goimports -w $(git status | grep modified: | sed -e 's/.* //')
log_test.go was left unchanged.
- update all the import statements
- run hack/pin-dependency.sh to change pinned dependency versions
- run hack/update-vendor.sh to update go.mod files and the vendor directory
- update the method signatures for custom reporters
Signed-off-by: Dave Chen <dave.chen@arm.com>
