put mutex around installplan creation

Signed-off-by: akihikokuroda <akihikokuroda2020@gmail.com>

pkg/controller/operators/catalog/operator.go

@@ -116,6 +116,7 @@ type Operator struct {
 	installPlanTimeout       time.Duration
 	bundleUnpackTimeout      time.Duration
 	clientFactory            clients.Factory
+	muInstallPlan            sync.Mutex
 }
 
 type CatalogSourceSyncFunc func(logger *logrus.Entry, in *v1alpha1.CatalogSource) (out *v1alpha1.CatalogSource, continueSync bool, syncError error)
@@ -1168,6 +1169,9 @@ func (o *Operator) ensureInstallPlan(logger *logrus.Entry, namespace string, gen
 		return nil, err
 	}
 
+	o.muInstallPlan.Lock()
+	defer o.muInstallPlan.Unlock()
+
 	for _, installPlan := range installPlans {
 		if installPlan.Spec.Generation == gen {
 			return reference.GetReference(installPlan)