runner: Allow previous catalyst jobs to finish (#234)

* runner: Allow previous catalyst jobs to finish

* runner: Ignore errors from previous attempts tho

* handler: Respond with 422 when task is not running

api/errors.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/golang/glog"
 	"github.com/livepeer/go-api-client"
+	"github.com/livepeer/task-runner/task"
 )
 
 type errorResponse struct {
@@ -20,6 +21,8 @@ func respondError(r *http.Request, rw http.ResponseWriter, defaultStatus int, er
 		response.Errors = append(response.Errors, err.Error())
 		if errors.Is(err, api.ErrNotExists) {
 			status = http.StatusNotFound
+		} else if errors.As(err, &task.InputError{}) {
+			status = http.StatusUnprocessableEntity
 		}
 	}
 	glog.Warningf("API ended in error. method=%s url=%q status=%d, errors=%+v", r.Method, r.URL, status, response.Errors)

task/runner.go

@@ -402,6 +402,10 @@ func (r *runner) getAssetAndOS(assetID string) (*api.Asset, *api.ObjectStore, dr
 	return asset, objectStore, osSession, nil
 }
 
+type InputError struct {
+	error
+}
+
 func (r *runner) HandleCatalysis(ctx context.Context, taskId, nextStep, attemptID string, callback *clients.CatalystCallback) error {
 	taskInfo, task, err := r.getTaskInfo(taskId, "catalysis", nil)
 	if err != nil {
@@ -413,10 +417,13 @@ func (r *runner) HandleCatalysis(ctx context.Context, taskId, nextStep, attemptI
 
 	if task.Status.Phase != api.TaskPhaseRunning &&
 		task.Status.Phase != api.TaskPhaseWaiting {
-		return fmt.Errorf("task %s is not running", taskId)
-	} else if curr := catalystTaskAttemptID(task); attemptID != "" && attemptID != curr {
-		return fmt.Errorf("outdated catalyst job callback, "+
-			"task has already been retried (callback: %s current: %s)", attemptID, curr)
+		return InputError{fmt.Errorf("task %s is not running", taskId)}
+	}
+	currAttempt := catalystTaskAttemptID(task)
+	isSameAttempt := attemptID == currAttempt
+	if !isSameAttempt {
+		glog.Warningf("Received outdated catalyst job callback, task has already been retried taskId=%s callbackAttempt=%s currentAttempt=%s",
+			task.ID, attemptID, currAttempt)
 	}
 
 	if callback.SourcePlayback != nil {
@@ -441,9 +448,12 @@ func (r *runner) HandleCatalysis(ctx context.Context, taskId, nextStep, attemptI
 	}
 
 	if callback.Status == catalystClients.TranscodeStatusError {
-		glog.Infof("Catalyst job failed for task type=%q id=%s error=%q unretriable=%v", task.Type, task.ID, callback.Error, callback.Unretriable)
-		err := NewCatalystError(callback.Error, callback.Unretriable)
-		return r.publishTaskResult(taskInfo, nil, err)
+		glog.Infof("Catalyst job failed for task type=%q id=%s attempt=%s error=%q unretriable=%v", task.Type, task.ID, attemptID, callback.Error, callback.Unretriable)
+		// Make sure not to fail the task with errors from previous attempts.
+		if isSameAttempt {
+			err := NewCatalystError(callback.Error, callback.Unretriable)
+			return r.publishTaskResult(taskInfo, nil, err)
+		}
 	} else if callback.Status == catalystClients.TranscodeStatusCompleted {
 		return r.scheduleTaskStep(task.ID, nextStep, callback)
 	}