From 5053776c1e6691f7c43295bef8dee28027059aca Mon Sep 17 00:00:00 2001
From: Zachary Seguin <zachary@zacharyseguin.ca>
Date: Wed, 22 Apr 2020 18:52:44 -0400
Subject: [PATCH] Add lease release tests in leader election

Kubernetes-commit: 9030fc47a24f630770b6966bc2b08153c57b4cc8
---
 tools/leaderelection/leaderelection_test.go | 155 ++++++++++++++++++++
 1 file changed, 155 insertions(+)

diff --git a/tools/leaderelection/leaderelection_test.go b/tools/leaderelection/leaderelection_test.go
index 10acfa7d54..c4703a9008 100644
--- a/tools/leaderelection/leaderelection_test.go
+++ b/tools/leaderelection/leaderelection_test.go
@@ -917,3 +917,158 @@ func TestTryAcquireOrRenewEndpointsLeases(t *testing.T) {
 func TestTryAcquireOrRenewConfigMapsLeases(t *testing.T) {
 	testTryAcquireOrRenewMultiLock(t, "configmapsleases")
 }
+
+func testReleaseLease(t *testing.T, objectType string) {
+	tests := []struct {
+		name           string
+		observedRecord rl.LeaderElectionRecord
+		observedTime   time.Time
+		reactors       []Reactor
+
+		expectSuccess    bool
+		transitionLeader bool
+		outHolder        string
+	}{
+		{
+			name: "release acquired lock from no object",
+			reactors: []Reactor{
+				{
+					verb:       "get",
+					objectType: objectType,
+					reaction: func(action fakeclient.Action) (handled bool, ret runtime.Object, err error) {
+						return true, nil, errors.NewNotFound(action.(fakeclient.GetAction).GetResource().GroupResource(), action.(fakeclient.GetAction).GetName())
+					},
+				},
+				{
+					verb:       "create",
+					objectType: objectType,
+					reaction: func(action fakeclient.Action) (handled bool, ret runtime.Object, err error) {
+						return true, action.(fakeclient.CreateAction).GetObject(), nil
+					},
+				},
+				{
+					verb:       "update",
+					objectType: objectType,
+					reaction: func(action fakeclient.Action) (handled bool, ret runtime.Object, err error) {
+						return true, action.(fakeclient.UpdateAction).GetObject(), nil
+					},
+				},
+			},
+			expectSuccess: true,
+			outHolder:     "",
+		},
+	}
+
+	for i := range tests {
+		test := &tests[i]
+		t.Run(test.name, func(t *testing.T) {
+			// OnNewLeader is called async so we have to wait for it.
+			var wg sync.WaitGroup
+			wg.Add(1)
+			var reportedLeader string
+			var lock rl.Interface
+
+			objectMeta := metav1.ObjectMeta{Namespace: "foo", Name: "bar"}
+			resourceLockConfig := rl.ResourceLockConfig{
+				Identity:      "baz",
+				EventRecorder: &record.FakeRecorder{},
+			}
+			c := &fake.Clientset{}
+			for _, reactor := range test.reactors {
+				c.AddReactor(reactor.verb, objectType, reactor.reaction)
+			}
+			c.AddReactor("*", "*", func(action fakeclient.Action) (bool, runtime.Object, error) {
+				t.Errorf("unreachable action. testclient called too many times: %+v", action)
+				return true, nil, fmt.Errorf("unreachable action")
+			})
+
+			switch objectType {
+			case "endpoints":
+				lock = &rl.EndpointsLock{
+					EndpointsMeta: objectMeta,
+					LockConfig:    resourceLockConfig,
+					Client:        c.CoreV1(),
+				}
+			case "configmaps":
+				lock = &rl.ConfigMapLock{
+					ConfigMapMeta: objectMeta,
+					LockConfig:    resourceLockConfig,
+					Client:        c.CoreV1(),
+				}
+			case "leases":
+				lock = &rl.LeaseLock{
+					LeaseMeta:  objectMeta,
+					LockConfig: resourceLockConfig,
+					Client:     c.CoordinationV1(),
+				}
+			}
+
+			lec := LeaderElectionConfig{
+				Lock:          lock,
+				LeaseDuration: 10 * time.Second,
+				Callbacks: LeaderCallbacks{
+					OnNewLeader: func(l string) {
+						defer wg.Done()
+						reportedLeader = l
+					},
+				},
+			}
+			observedRawRecord := GetRawRecordOrDie(t, objectType, test.observedRecord)
+			le := &LeaderElector{
+				config:            lec,
+				observedRecord:    test.observedRecord,
+				observedRawRecord: observedRawRecord,
+				observedTime:      test.observedTime,
+				clock:             clock.RealClock{},
+			}
+			if !le.tryAcquireOrRenew(context.Background()) {
+				t.Errorf("unexpected result of tryAcquireOrRenew: [succeeded=%v]", true)
+			}
+
+			le.maybeReportTransition()
+
+			// Wait for a response to the leader transition, and add 1 so that we can track the final transition.
+			wg.Wait()
+			wg.Add(1)
+
+			if test.expectSuccess != le.release() {
+				t.Errorf("unexpected result of release: [succeeded=%v]", !test.expectSuccess)
+			}
+
+			le.observedRecord.AcquireTime = metav1.Time{}
+			le.observedRecord.RenewTime = metav1.Time{}
+			if le.observedRecord.HolderIdentity != test.outHolder {
+				t.Errorf("expected holder:\n\t%+v\ngot:\n\t%+v", test.outHolder, le.observedRecord.HolderIdentity)
+			}
+			if len(test.reactors) != len(c.Actions()) {
+				t.Errorf("wrong number of api interactions")
+			}
+			if test.transitionLeader && le.observedRecord.LeaderTransitions != 1 {
+				t.Errorf("leader should have transitioned but did not")
+			}
+			if !test.transitionLeader && le.observedRecord.LeaderTransitions != 0 {
+				t.Errorf("leader should not have transitioned but did")
+			}
+			le.maybeReportTransition()
+			wg.Wait()
+			if reportedLeader != test.outHolder {
+				t.Errorf("reported leader was not the new leader. expected %q, got %q", test.outHolder, reportedLeader)
+			}
+		})
+	}
+}
+
+// Will test leader election using endpoints as the resource
+func TestReleaseLeaseEndpoints(t *testing.T) {
+	testReleaseLease(t, "endpoints")
+}
+
+// Will test leader election using endpoints as the resource
+func TestReleaseLeaseConfigMaps(t *testing.T) {
+	testReleaseLease(t, "configmaps")
+}
+
+// Will test leader election using endpoints as the resource
+func TestReleaseLeaseLeases(t *testing.T) {
+	testReleaseLease(t, "leases")
+}