Support service account override

docs/running-on-kubernetes.md

@@ -17,8 +17,10 @@ cluster, you may setup a test cluster on your local machine using
 * You must have appropriate permissions to create and list [pods](https://kubernetes.io/docs/user-guide/pods/),
 [ConfigMaps](https://kubernetes.io/docs/tasks/configure-pod-container/configmap/) and
 [secrets](https://kubernetes.io/docs/concepts/configuration/secret/) in your cluster. You can verify that
-you can list these resources by running `kubectl get pods` `kubectl get configmap`, and `kubectl get secrets` which
+you can list these resources by running `kubectl get pods`, `kubectl get configmap`, and `kubectl get secrets` which
 should give you a list of pods and configmaps (if any) respectively.
+  * The service account or credentials used by the driver pods must have appropriate permissions
+    as well for editing pod spec.
 * You must have a spark distribution with Kubernetes support. This may be obtained from the
 [release tarball](https://github.com/apache-spark-on-k8s/spark/releases) or by
 [building Spark with Kubernetes support](../resource-managers/kubernetes/README.md#building-spark-with-kubernetes-support).
@@ -107,6 +109,18 @@ Finally, notice that in the above example we specify a jar with a specific URI w
 the location of the example jar that is already in the Docker image. Using dependencies that are on your machine's local
 disk is discussed below.
 
+When Kubernetes [RBAC](https://kubernetes.io/docs/admin/authorization/rbac/) is enabled,
+the `default` service account used by the driver may not have appropriate pod `edit` permissions
+for launching executor pods. We recommend to add another service account, say `spark`, with
+the necessary privilege. For example:
+
+    kubectl create serviceaccount spark
+    kubectl create clusterrolebinding spark-edit --clusterrole edit  \
+        --serviceaccount default:spark --namespace default
+
+With this, one can add `--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark` to
+the spark-submit command line above to specify the service account to use.
+
 ## Dependency Management
 
 Application dependencies that are being submitted from your machine need to be sent to a **resource staging server**

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/kubernetes/submit/submitsteps/DriverKubernetesCredentialsStep.scala

@@ -44,6 +44,7 @@ private[spark] class DriverKubernetesCredentialsStep(
       s"$APISERVER_AUTH_DRIVER_MOUNTED_CONF_PREFIX.$CLIENT_CERT_FILE_CONF_SUFFIX")
   private val maybeMountedCaCertFile = submissionSparkConf.getOption(
       s"$APISERVER_AUTH_DRIVER_MOUNTED_CONF_PREFIX.$CA_CERT_FILE_CONF_SUFFIX")
+  private val driverServiceAccount = submissionSparkConf.get(KUBERNETES_SERVICE_ACCOUNT_NAME)
 
   override def configureDriver(driverSpec: KubernetesDriverSpec): KubernetesDriverSpec = {
     val driverSparkConf = driverSpec.driverSparkConf.clone()
@@ -81,7 +82,16 @@ private[spark] class DriverKubernetesCredentialsStep(
             .endVolume()
           .endSpec()
         .build()
-    }.getOrElse(driverSpec.driverPod)
+    }.getOrElse(
+      driverServiceAccount.map { account =>
+          new PodBuilder(driverSpec.driverPod)
+            .editOrNewSpec()
+              .withServiceAccount(account)
+              .withServiceAccountName(account)
+              .endSpec()
+            .build()
+      }.getOrElse(driverSpec.driverPod)
+    )
     val driverContainerWithMountedSecretVolume = kubernetesCredentialsSecret.map { secret =>
       new ContainerBuilder(driverSpec.driverContainer)
         .addNewVolumeMount()