Revert "promote e2e tests for taint-tolerations in predicates"

This reverts commit 4d3d364.

This commit promoted a test to conformance and also changed the test at
the same time. It should have been split up into two PRs to verify
whether the change had the intended effect. The test is now failing
consistently, so reverting.

Author: spiffxp

test/conformance/testdata/conformance.txt

@@ -267,7 +267,6 @@ test/e2e/node/pre_stop.go: "should call prestop when killing a pod"
 test/e2e/scheduling/predicates.go: "validates resource limits of pods that are allowed to run"
 test/e2e/scheduling/predicates.go: "validates that NodeSelector is respected if not matching"
 test/e2e/scheduling/predicates.go: "validates that NodeSelector is respected if matching"
-test/e2e/scheduling/predicates.go: "validates that taints-tolerations is respected if matching"
 test/e2e/scheduling/predicates.go: "validates that there is no conflict between pods with same hostPort but different hostIP and protocol"
 test/e2e/scheduling/predicates.go: "validates that there exists conflict between pods with same hostPort and protocol but one using 0.0.0.0 hostIP"
 test/e2e/scheduling/taints.go: "removing taint cancels eviction"

test/e2e/scheduling/predicates.go

@@ -454,14 +454,11 @@ var _ = SIGDescribe("SchedulerPredicates [Serial]", func() {
 		framework.ExpectEqual(labelPod.Spec.NodeName, nodeName)
 	})
 
-	/*
-			Release : v1.18
-			Testname: Scheduler, taints-tolerations matching
-			Description: Find an available node and taint it with a key with effect NoSchedule. Schedule a pod with a
-		        corresponding nodeLabel and toleration spec such that it should only be able to run on the selected node.
-		        Ensure that the pod is scheduled and running on the node.
-	*/
-	framework.ConformanceIt("validates that taints-tolerations is respected if matching [Disruptive]", func() {
+	// 1. Run a pod to get an available node, then delete the pod
+	// 2. Taint the node with a random taint
+	// 3. Try to relaunch the pod with tolerations tolerate the taints on node,
+	// and the pod's nodeName specified to the name of node found in step 1
+	ginkgo.It("validates that taints-tolerations is respected if matching", func() {
 		nodeName := getNodeThatCanRunPodWithoutToleration(f)
 
 		ginkgo.By("Trying to apply a random taint on the found node.")
@@ -489,7 +486,12 @@ var _ = SIGDescribe("SchedulerPredicates [Serial]", func() {
 			NodeSelector: map[string]string{labelKey: labelValue},
 		})
 
-		framework.ExpectNoError(e2epod.WaitForPodNameRunningInNamespace(cs, ns, tolerationPodName))
+		// check that pod got scheduled. We intentionally DO NOT check that the
+		// pod is running because this will create a race condition with the
+		// kubelet and the scheduler: the scheduler might have scheduled a pod
+		// already when the kubelet does not know about its new taint yet. The
+		// kubelet will then refuse to launch the pod.
+		framework.ExpectNoError(e2epod.WaitForPodNotPending(cs, ns, tolerationPodName))
 		deployedPod, err := cs.CoreV1().Pods(ns).Get(tolerationPodName, metav1.GetOptions{})
 		framework.ExpectNoError(err)
 		framework.ExpectEqual(deployedPod.Spec.NodeName, nodeName)