Fixed #1520 - Ended task can be removed

core/scheduler_event/scheduler_event.go

@@ -28,6 +28,7 @@ const (
 	TaskDeleted            = "Scheduler.TaskDeleted"
 	TaskStarted            = "Scheduler.TaskStarted"
 	TaskStopped            = "Scheduler.TaskStopped"
+	TaskEnded              = "Scheduler.TaskEnded"
 	TaskDisabled           = "Scheduler.TaskDisabled"
 	MetricCollected        = "Scheduler.MetricsCollected"
 	MetricCollectionFailed = "Scheduler.MetricCollectionFailed"
@@ -70,6 +71,15 @@ func (e TaskStoppedEvent) Namespace() string {
 	return TaskStopped
 }
 
+type TaskEndedEvent struct {
+	TaskID string
+	Source string
+}
+
+func (e TaskEndedEvent) Namespace() string {
+	return TaskEnded
+}
+
 type TaskDisabledEvent struct {
 	TaskID string
 	Why    string

core/task.go

@@ -52,7 +52,7 @@ var (
 		TaskStopped:  "Stopped",  // stopped but resumable
 		TaskSpinning: "Running",  // running
 		TaskFiring:   "Running",  // running (firing can happen so briefly we don't want to try and render it as a string state)
-		TaskEnded:    "Ended",    // ended, not resumable because the schedule will not fire again
+		TaskEnded:    "Ended",    // ended, but resumable if the schedule is still valid and might fire again
 		TaskStopping: "Stopping", // channel has been closed, wait for TaskStopped state
 	}
 )
@@ -65,6 +65,7 @@ type TaskWatcherHandler interface {
 	CatchCollection([]Metric)
 	CatchTaskStarted()
 	CatchTaskStopped()
+	CatchTaskEnded()
 	CatchTaskDisabled(string)
 }
 

docs/TASKS.md

@@ -12,10 +12,9 @@ A task can be in the following states:
 - **running:** a running task
 - **stopped:** a task that is not running
 - **disabled:** a task in a state not allowed to start. This happens when the task produces consecutive errors. A disabled task must be re-enabled before it can be started again. 
+- **ended:** a task for which the schedule is ended. At present this happens only for windowed schedule with defined _stop_timestamp_. An ended task is resumable if the schedule is still valid.
 
-
-![newtaskstatediagram2](https://cloud.githubusercontent.com/assets/21182867/19282545/a4179520-8fa3-11e6-9056-4fc3aa610983.png)
-
+![statediagram](https://cloud.githubusercontent.com/assets/11335874/23362447/0f0b9f74-fcf6-11e6-93d7-889a7ccdc45f.png)
 
 	    How To				                        |  Command
     ----------------------------------------|------------------------

mgmt/rest/client/task.go

@@ -157,7 +157,7 @@ func (c *Client) WatchTask(id string) *WatchTasksResult {
 				case rbody.TaskWatchTaskDisabled:
 					r.EventChan <- ste
 					r.Close()
-				case rbody.TaskWatchTaskStopped, rbody.TaskWatchTaskStarted, rbody.TaskWatchMetricEvent:
+				case rbody.TaskWatchTaskStopped, rbody.TaskWatchTaskEnded, rbody.TaskWatchTaskStarted, rbody.TaskWatchMetricEvent:
 					r.EventChan <- ste
 				}
 			}

mgmt/rest/rest_v1_test.go

@@ -119,7 +119,7 @@ func watchTask(id string, port int) *watchTaskResult {
 					r.eventChan <- ste.EventType
 					r.close()
 					return
-				case rbody.TaskWatchTaskStopped, rbody.TaskWatchTaskStarted, rbody.TaskWatchMetricEvent:
+				case rbody.TaskWatchTaskStopped, rbody.TaskWatchTaskEnded, rbody.TaskWatchTaskStarted, rbody.TaskWatchMetricEvent:
 					log.Info(ste.EventType)
 					r.eventChan <- ste.EventType
 				}

mgmt/rest/v1/rbody/task.go

@@ -36,6 +36,7 @@ const (
 	ScheduledTaskType              = "scheduled_task"
 	ScheduledTaskStartedType       = "scheduled_task_started"
 	ScheduledTaskStoppedType       = "scheduled_task_stopped"
+	ScheduledTaskEndedType         = "scheduled_task_ended"
 	ScheduledTaskRemovedType       = "scheduled_task_removed"
 	ScheduledTaskWatchingEndedType = "schedule_task_watch_ended"
 	ScheduledTaskEnabledType       = "scheduled_task_enabled"
@@ -46,6 +47,7 @@ const (
 	TaskWatchTaskDisabled = "task-disabled"
 	TaskWatchTaskStarted  = "task-started"
 	TaskWatchTaskStopped  = "task-stopped"
+	TaskWatchTaskEnded    = "task-ended"
 )
 
 type ScheduledTaskListReturned struct {

mgmt/rest/v1/task.go

@@ -149,7 +149,7 @@ func (s *apiV1) watchTask(w http.ResponseWriter, r *http.Request, p httprouter.P
 				// The client can decide to stop receiving on the stream on Task Stopped.
 				// We write the event to the buffer
 				fmt.Fprintf(w, "data: %s\n\n", e.ToJSON())
-			case rbody.TaskWatchTaskDisabled, rbody.TaskWatchTaskStopped:
+			case rbody.TaskWatchTaskDisabled, rbody.TaskWatchTaskStopped, rbody.TaskWatchTaskEnded:
 				// A disabled task should end the streaming and close the connection
 				fmt.Fprintf(w, "data: %s\n\n", e.ToJSON())
 				// Flush since we are sending nothing new
@@ -289,6 +289,12 @@ func (t *TaskWatchHandler) CatchTaskStopped() {
 	}
 }
 
+func (t *TaskWatchHandler) CatchTaskEnded() {
+	t.mChan <- rbody.StreamedTaskEvent{
+		EventType: rbody.TaskWatchTaskEnded,
+	}
+}
+
 func (t *TaskWatchHandler) CatchTaskDisabled(why string) {
 	t.mChan <- rbody.StreamedTaskEvent{
 		EventType: rbody.TaskWatchTaskDisabled,

mgmt/rest/v2/watch.go

@@ -37,6 +37,7 @@ const (
 	TaskWatchTaskDisabled = "task-disabled"
 	TaskWatchTaskStarted  = "task-started"
 	TaskWatchTaskStopped  = "task-stopped"
+	TaskWatchTaskEnded    = "task-ended"
 )
 
 // The amount of time to buffer streaming events before flushing in seconds
@@ -95,7 +96,7 @@ func (s *apiV2) watchTask(w http.ResponseWriter, r *http.Request, p httprouter.P
 				// The client can decide to stop receiving on the stream on Task Stopped.
 				// We write the event to the buffer
 				fmt.Fprintf(w, "data: %s\n\n", e.ToJSON())
-			case TaskWatchTaskDisabled, TaskWatchTaskStopped:
+			case TaskWatchTaskDisabled, TaskWatchTaskStopped, TaskWatchTaskEnded:
 				// A disabled task should end the streaming and close the connection
 				fmt.Fprintf(w, "data: %s\n\n", e.ToJSON())
 				// Flush since we are sending nothing new
@@ -165,6 +166,12 @@ func (t *TaskWatchHandler) CatchTaskStopped() {
 	}
 }
 
+func (t *TaskWatchHandler) CatchTaskEnded() {
+	t.mChan <- StreamedTaskEvent{
+		EventType: TaskWatchTaskEnded,
+	}
+}
+
 func (t *TaskWatchHandler) CatchTaskDisabled(why string) {
 	t.mChan <- StreamedTaskEvent{
 		EventType: TaskWatchTaskDisabled,

scheduler/scheduler.go

@@ -64,6 +64,8 @@ var (
 	ErrTaskDisabledNotRunnable = errors.New("Task is disabled. Cannot be started.")
 	// ErrTaskDisabledNotStoppable - The error message for when a task is disabled and cannot be stopped
 	ErrTaskDisabledNotStoppable = errors.New("Task is disabled. Only running tasks can be stopped.")
+	// ErrTaskEndedNotStoppable - The error message for when a task is ended and cannot be stopped
+	ErrTaskEndedNotStoppable = errors.New("Task is ended. Only running tasks can be stopped.")
 )
 
 type schedulerState int
@@ -471,6 +473,7 @@ func (s *scheduler) startTask(id, source string) []serror.SnapError {
 			serror.New(ErrTaskDisabledNotRunnable),
 		}
 	}
+
 	if t.state == core.TaskFiring || t.state == core.TaskSpinning {
 		logger.WithFields(log.Fields{
 			"task-id":    t.ID(),
@@ -481,6 +484,16 @@ func (s *scheduler) startTask(id, source string) []serror.SnapError {
 		}
 	}
 
+	// Ensure the schedule is valid at this point and time.
+	if err := t.schedule.Validate(); err != nil {
+		errs := []serror.SnapError{
+			serror.New(err),
+		}
+		f := buildErrorsLog(errs, logger)
+		f.Error("schedule passed not valid")
+		return errs
+	}
+
 	// Group dependencies by the node they live on
 	// and subscribe to them.
 	depGroups := getWorkflowPlugins(t.workflow.processNodes, t.workflow.publishNodes, t.workflow.metrics)
@@ -559,6 +572,14 @@ func (s *scheduler) stopTask(id, source string) []serror.SnapError {
 		return []serror.SnapError{
 			serror.New(ErrTaskAlreadyStopped),
 		}
+	case core.TaskEnded:
+		logger.WithFields(log.Fields{
+			"task-id":    t.ID(),
+			"task-state": t.State(),
+		}).Error("task is already ended")
+		return []serror.SnapError{
+			serror.New(ErrTaskEndedNotStoppable),
+		}
 	case core.TaskDisabled:
 		logger.WithFields(log.Fields{
 			"task-id":    t.ID(),
@@ -768,6 +789,14 @@ func (s *scheduler) HandleGomitEvent(e gomit.Event) {
 			"task-id":         v.TaskID,
 		}).Debug("event received")
 		s.taskWatcherColl.handleTaskStopped(v.TaskID)
+	case *scheduler_event.TaskEndedEvent:
+		log.WithFields(log.Fields{
+			"_module":         "scheduler-events",
+			"_block":          "handle-events",
+			"event-namespace": e.Namespace(),
+			"task-id":         v.TaskID,
+		}).Debug("event received")
+		s.taskWatcherColl.handleTaskEnded(v.TaskID)
 	case *scheduler_event.TaskDisabledEvent:
 		log.WithFields(log.Fields{
 			"_module":         "scheduler-events",