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>
This patch makes the CRI `v1` API the new project-wide default version.
To allow backwards compatibility, a fallback to `v1alpha2` has been added
as well. This fallback can either used by automatically determined by
the kubelet.
Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
Prevent Kubelet from incorrectly interpreting "not yet started" pods as "ready to terminate pods" by unifying responsibility for pod lifecycle into pod worker
A number of race conditions exist when pods are terminated early in
their lifecycle because components in the kubelet need to know "no
running containers" or "containers can't be started from now on" but
were relying on outdated state.
Only the pod worker knows whether containers are being started for
a given pod, which is required to know when a pod is "terminated"
(no running containers, none coming). Move that responsibility and
podKiller function into the pod workers, and have everything that
was killing the pod go into the UpdatePod loop. Split syncPod into
three phases - setup, terminate containers, and cleanup pod - and
have transitions between those methods be visible to other
components. After this change, to kill a pod you tell the pod worker
to UpdatePod({UpdateType: SyncPodKill, Pod: pod}).
Several places in the kubelet were incorrect about whether they
were handling terminating (should stop running, might have
containers) or terminated (no running containers) pods. The pod worker
exposes methods that allow other loops to know when to set up or tear
down resources based on the state of the pod - these methods remove
the possibility of race conditions by ensuring a single component is
responsible for knowing each pod's allowed state and other components
simply delegate to checking whether they are in the window by UID.
Removing containers now no longer blocks final pod deletion in the
API server and are handled as background cleanup. Node shutdown
no longer marks pods as failed as they can be restarted in the
next step.
See https://docs.google.com/document/d/1Pic5TPntdJnYfIpBeZndDelM-AbS4FN9H2GTLFhoJ04/edit# for details
The kubelet would attempt to create a new sandbox for a pod whose
RestartPolicy is OnFailure even after all container succeeded. It caused
unnecessary CRI and CNI calls, confusing logs and conflicts between the
routine that creates the new sandbox and the routine that kills the Pod.
This patch checks the containers to start and stops creating sandbox if
no container is supposed to start.
add host file write for podIPs
update tests
remove import alias
update type check
update type check
remove import alias
update open api spec
add tests
update test
add tests
address review comments
update imports
remove todo and import alias
If kubelet never gets past sandbox creation (i.e., never attempted to
create containers for a pod), it should retry the sandbox creation on
failure, regardless of the restart policy of the pod.
We've changed the Ephemeral Containers API, and container type will no
longer be required. Since this is the only feature using it, remove it.
This reverts commit ba6f31a6c6.
Users must not be allowed to step outside the volume with subPath.
Therefore the final subPath directory must be "locked" somehow
and checked if it's inside volume.
On Windows, we lock the directories. On Linux, we bind-mount the final
subPath into /var/lib/kubelet/pods/<uid>/volume-subpaths/<container name>/<subPathName>,
it can't be changed to symlink user once it's bind-mounted.
This also incorporates the version string into the package name so
that incompatibile versions will fail to connect.
Arbitrary choices:
- The proto3 package name is runtime.v1alpha2. The proto compiler
normally translates this to a go package of "runtime_v1alpha2", but
I renamed it to "v1alpha2" for consistency with existing packages.
- kubelet/apis/cri is used as "internalapi". I left it alone and put the
public "runtimeapi" in kubelet/apis/cri/runtime.
This is part of the "Debug Containers" feature and is hidden behind
a feature gate. Debug containers have no stored spec, so this new
runtime label allows the kubelet to treat containers differently
without relying on spec.
Automatic merge from submit-queue (batch tested with PRs 53631, 56960). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Remove unused code in UT files in pkg/
**What this PR does / why we need it**:
Remove unused code in UT files in pkg/ .
**Release note**:
```release-note
NONE
```
Whenever pod sandbox needs to be recreated, all containers associated
with it will be killed by kubelet. This change ensures that the init
containers will be rerun in such cases.
The change also refactors the compute logic so that the control flow of
init containers act is more aligned with the regular containers. Unit
tests are added to verify the logic.
