ignore poststop task in alloc health tracker (#9548), fixes #9361

* investigating where to ignore poststop task in alloc health tracker

* ignore poststop when setting latest start time for allocation

* clean up logic

* lifecycle: isolate mocks for poststop deployment test

* lifecycle: update comments in tracker

Co-authored-by: Jasmine Dahilig <jasmine@dahilig.com>

client/allochealth/tracker.go

@@ -66,9 +66,9 @@ type Tracker struct {
 	// not needed
 	allocStopped chan struct{}
 
-	// lifecycleTasks is a set of tasks with lifecycle hook set and may
-	// terminate without affecting alloc health
-	lifecycleTasks map[string]bool
+	// lifecycleTasks is a map of ephemeral tasks and their lifecycle hooks.
+	// These tasks may terminate without affecting alloc health
+	lifecycleTasks map[string]string
 
 	// l is used to lock shared fields listed below
 	l sync.Mutex
@@ -110,7 +110,7 @@ func NewTracker(parentCtx context.Context, logger hclog.Logger, alloc *structs.A
 		consulClient:        consulClient,
 		checkLookupInterval: consulCheckLookupInterval,
 		logger:              logger,
-		lifecycleTasks:      map[string]bool{},
+		lifecycleTasks:      map[string]string{},
 	}
 
 	t.taskHealth = make(map[string]*taskHealthState, len(t.tg.Tasks))
@@ -118,7 +118,7 @@ func NewTracker(parentCtx context.Context, logger hclog.Logger, alloc *structs.A
 		t.taskHealth[task.Name] = &taskHealthState{task: task}
 
 		if task.Lifecycle != nil && !task.Lifecycle.Sidecar {
-			t.lifecycleTasks[task.Name] = true
+			t.lifecycleTasks[task.Name] = task.Lifecycle.Hook
 		}
 
 		for _, s := range task.Services {
@@ -277,8 +277,15 @@ func (t *Tracker) watchTaskEvents() {
 		// Detect if the alloc is unhealthy or if all tasks have started yet
 		latestStartTime := time.Time{}
 		for taskName, state := range alloc.TaskStates {
+			// If the task is a poststop task we do not want to evaluate it
+			// since it will remain pending until the main task has finished
+			// or exited.
+			if t.lifecycleTasks[taskName] == structs.TaskLifecycleHookPoststop {
+				continue
+			}
+
 			// One of the tasks has failed so we can exit watching
-			if state.Failed || (!state.FinishedAt.IsZero() && !t.lifecycleTasks[taskName]) {
+			if state.Failed || !state.FinishedAt.IsZero() {
 				t.setTaskHealth(false, true)
 				return
 			}
@@ -299,6 +306,7 @@ func (t *Tracker) watchTaskEvents() {
 			t.l.Lock()
 			t.allocFailed = true
 			t.l.Unlock()
+
 			t.setTaskHealth(false, true)
 			return
 		}

client/allochealth/tracker_test.go

@@ -89,6 +89,46 @@ func TestTracker_Checks_Healthy(t *testing.T) {
 	}
 }
 
+func TestTracker_Checks_PendingPostStop_Healthy(t *testing.T) {
+	t.Parallel()
+
+	alloc := mock.LifecycleAllocWithPoststopDeploy()
+	alloc.Job.TaskGroups[0].Migrate.MinHealthyTime = 1 // let's speed things up
+
+	// Synthesize running alloc and tasks
+	alloc.ClientStatus = structs.AllocClientStatusRunning
+	alloc.TaskStates = map[string]*structs.TaskState{
+		"web": {
+			State:     structs.TaskStateRunning,
+			StartedAt: time.Now(),
+		},
+		"post": {
+			State: structs.TaskStatePending,
+		},
+	}
+
+	logger := testlog.HCLogger(t)
+	b := cstructs.NewAllocBroadcaster(logger)
+	defer b.Close()
+
+	consul := consul.NewMockConsulServiceClient(t, logger)
+	ctx, cancelFn := context.WithCancel(context.Background())
+	defer cancelFn()
+
+	checkInterval := 10 * time.Millisecond
+	tracker := NewTracker(ctx, logger, alloc, b.Listen(), consul,
+		time.Millisecond, true)
+	tracker.checkLookupInterval = checkInterval
+	tracker.Start()
+
+	select {
+	case <-time.After(4 * checkInterval):
+		require.Fail(t, "timed out while waiting for health")
+	case h := <-tracker.HealthyCh():
+		require.True(t, h)
+	}
+}
+
 func TestTracker_Checks_Unhealthy(t *testing.T) {
 	t.Parallel()
 

nomad/mock/mock.go

@@ -529,6 +529,186 @@ func LifecycleAlloc() *structs.Allocation {
 	return alloc
 }
 
+func LifecycleJobWithPoststopDeploy() *structs.Job {
+	job := &structs.Job{
+		Region:      "global",
+		ID:          fmt.Sprintf("mock-service-%s", uuid.Generate()),
+		Name:        "my-job",
+		Namespace:   structs.DefaultNamespace,
+		Type:        structs.JobTypeBatch,
+		Priority:    50,
+		AllAtOnce:   false,
+		Datacenters: []string{"dc1"},
+		Constraints: []*structs.Constraint{
+			{
+				LTarget: "${attr.kernel.name}",
+				RTarget: "linux",
+				Operand: "=",
+			},
+		},
+		TaskGroups: []*structs.TaskGroup{
+			{
+				Name:    "web",
+				Count:   1,
+				Migrate: structs.DefaultMigrateStrategy(),
+				RestartPolicy: &structs.RestartPolicy{
+					Attempts: 0,
+					Interval: 10 * time.Minute,
+					Delay:    1 * time.Minute,
+					Mode:     structs.RestartPolicyModeFail,
+				},
+				Tasks: []*structs.Task{
+					{
+						Name:   "web",
+						Driver: "mock_driver",
+						Config: map[string]interface{}{
+							"run_for": "1s",
+						},
+						LogConfig: structs.DefaultLogConfig(),
+						Resources: &structs.Resources{
+							CPU:      1000,
+							MemoryMB: 256,
+						},
+					},
+					{
+						Name:   "side",
+						Driver: "mock_driver",
+						Config: map[string]interface{}{
+							"run_for": "1s",
+						},
+						Lifecycle: &structs.TaskLifecycleConfig{
+							Hook:    structs.TaskLifecycleHookPrestart,
+							Sidecar: true,
+						},
+						LogConfig: structs.DefaultLogConfig(),
+						Resources: &structs.Resources{
+							CPU:      1000,
+							MemoryMB: 256,
+						},
+					},
+					{
+						Name:   "post",
+						Driver: "mock_driver",
+						Config: map[string]interface{}{
+							"run_for": "1s",
+						},
+						Lifecycle: &structs.TaskLifecycleConfig{
+							Hook: structs.TaskLifecycleHookPoststop,
+						},
+						LogConfig: structs.DefaultLogConfig(),
+						Resources: &structs.Resources{
+							CPU:      1000,
+							MemoryMB: 256,
+						},
+					},
+					{
+						Name:   "init",
+						Driver: "mock_driver",
+						Config: map[string]interface{}{
+							"run_for": "1s",
+						},
+						Lifecycle: &structs.TaskLifecycleConfig{
+							Hook:    structs.TaskLifecycleHookPrestart,
+							Sidecar: false,
+						},
+						LogConfig: structs.DefaultLogConfig(),
+						Resources: &structs.Resources{
+							CPU:      1000,
+							MemoryMB: 256,
+						},
+					},
+				},
+			},
+		},
+		Meta: map[string]string{
+			"owner": "armon",
+		},
+		Status:         structs.JobStatusPending,
+		Version:        0,
+		CreateIndex:    42,
+		ModifyIndex:    99,
+		JobModifyIndex: 99,
+	}
+	job.Canonicalize()
+	return job
+}
+
+func LifecycleAllocWithPoststopDeploy() *structs.Allocation {
+	alloc := &structs.Allocation{
+		ID:        uuid.Generate(),
+		EvalID:    uuid.Generate(),
+		NodeID:    "12345678-abcd-efab-cdef-123456789abc",
+		Namespace: structs.DefaultNamespace,
+		TaskGroup: "web",
+
+		// TODO Remove once clientv2 gets merged
+		Resources: &structs.Resources{
+			CPU:      500,
+			MemoryMB: 256,
+		},
+		TaskResources: map[string]*structs.Resources{
+			"web": {
+				CPU:      1000,
+				MemoryMB: 256,
+			},
+			"init": {
+				CPU:      1000,
+				MemoryMB: 256,
+			},
+			"side": {
+				CPU:      1000,
+				MemoryMB: 256,
+			},
+			"post": {
+				CPU:      1000,
+				MemoryMB: 256,
+			},
+		},
+
+		AllocatedResources: &structs.AllocatedResources{
+			Tasks: map[string]*structs.AllocatedTaskResources{
+				"web": {
+					Cpu: structs.AllocatedCpuResources{
+						CpuShares: 1000,
+					},
+					Memory: structs.AllocatedMemoryResources{
+						MemoryMB: 256,
+					},
+				},
+				"init": {
+					Cpu: structs.AllocatedCpuResources{
+						CpuShares: 1000,
+					},
+					Memory: structs.AllocatedMemoryResources{
+						MemoryMB: 256,
+					},
+				},
+				"side": {
+					Cpu: structs.AllocatedCpuResources{
+						CpuShares: 1000,
+					},
+					Memory: structs.AllocatedMemoryResources{
+						MemoryMB: 256,
+					},
+				},
+				"post": {
+					Cpu: structs.AllocatedCpuResources{
+						CpuShares: 1000,
+					},
+					Memory: structs.AllocatedMemoryResources{
+						MemoryMB: 256,
+					},
+				},
+			},
+		},
+		Job:           LifecycleJobWithPoststopDeploy(),
+		DesiredStatus: structs.AllocDesiredStatusRun,
+		ClientStatus:  structs.AllocClientStatusPending,
+	}
+	alloc.JobID = alloc.Job.ID
+	return alloc
+}
+
 func MaxParallelJob() *structs.Job {
 	update := *structs.DefaultUpdateStrategy
 	update.MaxParallel = 0