Fixes #1467 (issue when deleting SparkApplication without metrics server) (#1530)

Author: aneagoe

charts/spark-operator-chart/Chart.yaml

@@ -1,8 +1,8 @@
 apiVersion: v2
 name: spark-operator
 description: A Helm chart for Spark on Kubernetes operator
-version: 1.1.21
-appVersion: v1beta2-1.3.5-3.1.1
+version: 1.1.22
+appVersion: v1beta2-1.3.6-3.1.1
 keywords:
   - spark
 home: https://github.com/GoogleCloudPlatform/spark-on-k8s-operator

pkg/controller/sparkapplication/controller.go

@@ -446,7 +446,9 @@ func (c *Controller) getAndUpdateAppState(app *v1beta2.SparkApplication) error {
 }
 
 func (c *Controller) handleSparkApplicationDeletion(app *v1beta2.SparkApplication) {
-	c.metrics.exportMetricsOnDelete(app)
+	if c.metrics != nil {
+		c.metrics.exportMetricsOnDelete(app)
+	}
 	// SparkApplication deletion requested, lets delete driver pod.
 	if err := c.deleteSparkResources(app); err != nil {
 		glog.Errorf("failed to delete resources associated with deleted SparkApplication %s/%s: %v", app.Namespace, app.Name, err)