Revert "fix: avoid instance creation if the engine image is not ready"

Longhorn 11397, 11994, 11995

This reverts commit 5c4ea9b.

Author: shuo-wu

controller/engine_controller.go

@@ -444,14 +444,6 @@ func (ec *EngineController) CreateInstance(obj interface{}) (*longhorn.InstanceP
 	if e.Spec.VolumeName == "" || e.Spec.NodeID == "" {
 		return nil, fmt.Errorf("missing parameters for engine instance creation: %v", e)
 	}
-	isReady, err := ec.ds.CheckDataEngineImageReadiness(e.Spec.Image, e.Spec.DataEngine, e.Spec.NodeID)
-	if err != nil {
-		return nil, err
-	}
-	if !isReady {
-		return nil, fmt.Errorf("data engine %v image %v is not ready on node %v for engine %s instance creation", e.Spec.DataEngine, e.Spec.Image, e.Spec.NodeID, e.Name)
-	}
-
 	frontend := e.Spec.Frontend
 	if e.Spec.DisableFrontend {
 		frontend = longhorn.VolumeFrontendEmpty

controller/replica_controller.go

@@ -322,14 +322,7 @@ func (rc *ReplicaController) CreateInstance(obj interface{}) (*longhorn.Instance
 		return nil, fmt.Errorf("missing parameters for replica instance creation: %v", r)
 	}
 
-	isReady, err := rc.ds.CheckDataEngineImageReadiness(r.Spec.Image, r.Spec.DataEngine, r.Spec.NodeID)
-	if err != nil {
-		return nil, err
-	}
-	if !isReady {
-		return nil, fmt.Errorf("data engine %v image %v is not ready on node %v for replica %s instance creation", r.Spec.DataEngine, r.Spec.Image, r.Spec.NodeID, r.Name)
-	}
-
+	var err error
 	backingImagePath := ""
 	if r.Spec.BackingImage != "" {
 		if backingImagePath, err = rc.GetBackingImagePathForReplicaStarting(r); err != nil {