Code change:
<ins> // +build linux /* Copyright 2021 The Kubernetes Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package e2enode import ( "time" "golang.org/x/sys/unix" "github.com/onsi/ginkgo" "github.com/onsi/gomega" "k8s.io/kubernetes/test/e2e/framework" ) const contentionLockFile = "/var/run/kubelet.lock" var _ = SIGDescribe("Lock contention [Slow] [Disruptive] [NodeFeature:LockContention]", func() { ginkgo.It("Kubelet should stop when the test acquires the lock on lock file and restart once the lock is released", func() { ginkgo.By("perform kubelet health check to check if kubelet is healthy and running.") // Precautionary check that kubelet is healthy before running the test. gomega.Expect(kubeletHealthCheck(kubeletHealthCheckURL)).To(gomega.BeTrue()) ginkgo.By("acquiring the lock on lock file i.e /var/run/kubelet.lock") // Open the file with the intention to acquire the lock, this would imitate the behaviour // of the another kubelet(self-hosted) trying to start. When this lock contention happens // it is expected that the running kubelet must terminate and wait until the lock on the // lock file is released. // Kubelet uses the same approach to acquire the lock on lock file as shown here: // https://github.com/kubernetes/kubernetes/blob/master/cmd/kubelet/app/server.go#L530-#L546 // and the function definition of Acquire is here: // https://github.com/kubernetes/kubernetes/blob/master/pkg/util/flock/flock_unix.go#L25 fd, err := unix.Open(contentionLockFile, unix.O_CREAT|unix.O_RDWR|unix.O_CLOEXEC, 0600) framework.ExpectNoError(err) // Defer the lock release in case test fails and we don't reach the step of the release // lock. This ensures that we release the lock for sure. defer func() { err = unix.Flock(fd, unix.LOCK_UN) framework.ExpectNoError(err) }() // Acquire lock. err = unix.Flock(fd, unix.LOCK_EX) framework.ExpectNoError(err) ginkgo.By("verifying the kubelet is not healthy as there was a lock contention.") // Once the lock is acquired, check if the kubelet is in healthy state or not. // It should not be. gomega.Eventually(func() bool { return kubeletHealthCheck(kubeletHealthCheckURL) }, 10*time.Second, time.Second).Should(gomega.BeFalse()) ginkgo.By("releasing the lock on lock file i.e /var/run/kubelet.lock") // Release the lock. err = unix.Flock(fd, unix.LOCK_UN) framework.ExpectNoError(err) ginkgo.By("verifying the kubelet is healthy again after the lock was released.") // Releasing the lock triggers kubelet to re-acquire the lock and restart. // Hence the kubelet should report healthy state. gomega.Eventually(func() bool { return kubeletHealthCheck(kubeletHealthCheckURL) }, 10*time.Second, time.Second).Should(gomega.BeTrue()) }) }) </ins>

Related discussion:
text: <!-- Please only use this template for submitting enhancement requests --What would you like to be : Node E2E tests for Kubelet lock contention flags: --exit-on-lock-contention --lock-file Why is this needed: These flags are being graduated to KubeletConfiguration on , we should add E2E tests for these flags before proceeding.
This issue is currently awaiting triage. If a SIG or subproject determines this is a relevant issue, they will accept it by applying the label and provide further guidance. The label can be by org members by writing in a comment. <detailsInstructions for interacting with me using PR comments are available . If you have questions or suggestions related to my behavior, please file an issue against the repository. </details
/sig node /wg component-standard
Issues go stale after 90d of inactivity. Mark the issue as fresh with . Stale issues rot after an additional 30d of inactivity and eventually close. If this issue is safe to close now please do so with . Send feedback to sig-contributor-experience at . /lifecycle stale
Stale issues rot after 30d of inactivity. Mark the issue as fresh with . Rotten issues close after an additional 30d of inactivity. If this issue is safe to close now please do so with . Send feedback to sig-contributor-experience at . /lifecycle rotten
Rotten issues close after 30d of inactivity. Reopen the issue with . Mark the issue as fresh with . Send feedback to sig-contributor-experience at . /close
Closing this issue. <detailsIn response to : Rotten issues close after 30d of inactivity. Reopen the issue with . Mark the issue as fresh with . /close Instructions for interacting with me using PR comments are available . If you have questions or suggestions related to my behavior, please file an issue against the repository. </details