feat(alerting): adds ok as no data option

closes #6866

pkg/models/alert.go

@@ -20,9 +20,10 @@ const (
 )
 
 const (
+	NoDataSetOK       NoDataOption = "ok"
 	NoDataSetNoData   NoDataOption = "no_data"
-	NoDataSetAlerting NoDataOption = "alerting"
 	NoDataKeepState   NoDataOption = "keep_state"
+	NoDataSetAlerting NoDataOption = "alerting"
 )
 
 const (
@@ -35,7 +36,7 @@ func (s AlertStateType) IsValid() bool {
 }
 
 func (s NoDataOption) IsValid() bool {
-	return s == NoDataSetNoData || s == NoDataSetAlerting || s == NoDataKeepState
+	return s == NoDataSetNoData || s == NoDataSetAlerting || s == NoDataKeepState || s == NoDataSetOK
 }
 
 func (s NoDataOption) ToAlertState() AlertStateType {

public/app/features/alerting/alert_def.ts

@@ -47,6 +47,7 @@ var noDataModes = [
   {text: 'Alerting', value: 'alerting'},
   {text: 'No Data', value: 'no_data'},
   {text: 'Keep Last State', value: 'keep_state'},
+  {text: 'Ok', value: 'ok'},
 ];
 
 var executionErrorModes = [