Currently, there are some unit tests that are failing on Windows due to
various reasons:
- On Windows, consecutive time.Now() calls may return the same timestamp, which would cause
the TestFreeSpaceRemoveByLeastRecentlyUsed test to flake.
- tests in kuberuntime_container_windows_test.go fail on Nodes that have fewer than 3 CPUs,
expecting the CPU max set to be more than 100% of available CPUs, which is not possible.
- calls in summary_windows_test.go are missing context.
- filterTerminatedContainerInfoAndAssembleByPodCgroupKey will filter and group container
information by the Pod cgroup key, if it exists. However, we don't have cgroups on Windows,
thus we can't make the same assertions.
Added new gRPC call 'ListPodSanboxMetrics' which would return additional
container stats currently supported by cAdvisor, but outside the scope
of /stats/summary api. Added new types to support metric exporting of
prometheus, including Metric and other subfields. Added fake runtime
changes associated with the CRI changes.
The path module has a few different functions:
Clean, Split, Join, Ext, Dir, Base, IsAbs. These functions do not
take into account the OS-specific path separator, meaning that they
won't behave as intended on Windows.
For example, Dir is supposed to return all but the last element of the
path. For the path "C:\some\dir\somewhere", it is supposed to return
"C:\some\dir\", however, it returns ".".
Instead of these functions, the ones in filepath should be used instead.
Currently, there are some unit tests that are failing on Windows due to
various reasons:
- config options not supported on Windows.
- files not closed, which means that they cannot be removed / renamed.
- paths not properly joined (filepath.Join should be used).
- time.Now() is not as precise on Windows, which means that 2
consecutive calls may return the same timestamp.
- different error messages on Windows.
- files have \r\n line endings on Windows.
- /tmp directory being used, which might not exist on Windows. Instead,
the OS-specific Temp directory should be used.
- the default value for Kubelet's EvictionHard field was containing
OS-specific fields. This is now moved, the field is now set during
Kubelet's initialization, after the config file is read.
Align the behavior of HTTP-based lifecycle handlers and HTTP-based
probers, converging on the probers implementation. This fixes multiple
deficiencies in the current implementation of lifecycle handlers
surrounding what functionality is available.
The functionality is gated by the features.ConsistentHTTPGetHandlers feature gate.
Some of the unit tests cannot pass on Windows due to various reasons:
- fsnotify does not have a Windows implementation.
- Proxy Mode IPVS not supported on Windows.
- Seccomp not supported on Windows.
- VolumeMode=Block is not supported on Windows.
- iSCSI volumes are mounted differently on Windows, and iscsiadm is a
Linux utility.
There is a corner case when blocking Pod termination via a lifecycle
preStop hook, for example by using this StateFulSet:
```yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: web
spec:
selector:
matchLabels:
app: ubi
serviceName: "ubi"
replicas: 1
template:
metadata:
labels:
app: ubi
spec:
terminationGracePeriodSeconds: 1000
containers:
- name: ubi
image: ubuntu:22.04
command: ['sh', '-c', 'echo The app is running! && sleep 360000']
ports:
- containerPort: 80
name: web
lifecycle:
preStop:
exec:
command:
- /bin/sh
- -c
- 'echo aaa; trap : TERM INT; sleep infinity & wait'
```
After creation, downscaling, forced deletion and upscaling of the
replica like this:
```
> kubectl apply -f sts.yml
> kubectl scale sts web --replicas=0
> kubectl delete pod web-0 --grace-period=0 --force
> kubectl scale sts web --replicas=1
```
We will end up having two pods running by the container runtime, while
the API only reports one:
```
> kubectl get pods
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 92s
```
```
> sudo crictl pods
POD ID CREATED STATE NAME NAMESPACE ATTEMPT RUNTIME
e05bb7dbb7e44 12 minutes ago Ready web-0 default 0 (default)
d90088614c73b 12 minutes ago Ready web-0 default 0 (default)
```
When now running `kubectl exec -it web-0 -- ps -ef`, there is a random chance that we hit the wrong
container reporting the lifecycle command `/bin/sh -c echo aaa; trap : TERM INT; sleep infinity & wait`.
This is caused by the container lookup via its name (and no podUID) at:
02109414e8/pkg/kubelet/kubelet_pods.go (L1905-L1914)
And more specifiy by the conversion of the pod result map to a slice in `GetPods`:
02109414e8/pkg/kubelet/kuberuntime/kuberuntime_manager.go (L407-L411)
We now solve that unexpected behavior by tracking the creation time of
the pod and sorting the result based on that. This will cause to always
match the most recently created pod.
Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
cpu.cfs_period_us is measured in microseconds in the kernel but
provided in time.Duration by the user, that change clarifies the code
to make this evident to the reader.
Also, the minimum value for that feature is 1ms and not 1μs, and this
change alters the validation to reject values smaller than 1ms.
cpu.cfs_period_us is 100μs by default despite having an "ms" unit
for some unfortunate reason. Documentation:
https://www.kernel.org/doc/html/latest/scheduler/sched-bwc.html#management
The desired effect of that change is to match
k8s default `CPUCFSQuotaPeriod` value (100ms before that change)
with one used in k8s without the `CustomCPUCFSQuotaPeriod` flag enabled
and Linux CFS (100us, 1000x smaller than 100ms).
