address comments

Author: dcoliversun

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/KubernetesUtils.scala

@@ -387,27 +387,20 @@ object KubernetesUtils extends Logging {
    */
   @Since("3.4.0")
   def buildEnvVars(env: Map[String, String]): Seq[EnvVar] = {
-    if (env.isEmpty) {
-      Seq.empty
-    } else {
       env.filter( env => env._2 != null)
          .map { env =>
            new EnvVarBuilder()
              .withName(env._1)
              .withValue(env._2)
              .build()
-      }
-    }.toSeq
+      }.toSeq
   }
 
   /**
    * This function builds the EnvVar objects for each field ref env.
    */
   @Since("3.4.0")
   def buildEnvVarsWithFieldRef(env: Seq[(String, String, String)]): Seq[EnvVar] = {
-    if (env.isEmpty) {
-      Seq.empty
-    } else {
       env.filter( env => env._2 != null && env._3 != null)
          .map { env =>
            new EnvVarBuilder()
@@ -417,6 +410,5 @@ object KubernetesUtils extends Logging {
                .build())
              .build()
       }
-    }
   }
 }

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/features/BasicDriverFeatureStep.scala

@@ -75,7 +75,7 @@ private[spark] class BasicDriverFeatureStep(conf: KubernetesDriverConf)
 
   override def configurePod(pod: SparkPod): SparkPod = {
     val driverCustomEnvs = KubernetesUtils.buildEnvVars(
-      conf.environment + (ENV_APPLICATION_ID -> conf.appId))
+      Map(ENV_APPLICATION_ID -> conf.appId) ++ conf.environment)
     val driverCpuQuantity = new Quantity(driverCoresRequest)
     val driverMemoryQuantity = new Quantity(s"${driverMemoryWithOverheadMiB}Mi")
     val maybeCpuLimitQuantity = driverLimitCores.map { limitCores =>

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/features/BasicExecutorFeatureStep.scala

@@ -140,10 +140,10 @@ private[spark] class BasicExecutorFeatureStep(
           // This is to set the SPARK_CONF_DIR to be /opt/spark/conf
           ENV_SPARK_CONF_DIR -> SPARK_CONF_DIR_INTERNAL,
           ENV_EXECUTOR_ID -> kubernetesConf.executorId,
-          ENV_RESOURCE_PROFILE_ID -> resourceProfile.id.toString,
-          ENV_CLASSPATH-> kubernetesConf.get(EXECUTOR_CLASS_PATH).orNull)
+          ENV_RESOURCE_PROFILE_ID -> resourceProfile.id.toString)
           ++ kubernetesConf.environment
           ++ sparkAuthSecret
+          ++ Map(ENV_CLASSPATH-> kubernetesConf.get(EXECUTOR_CLASS_PATH).orNull)
           ++ allOpts) ++
         KubernetesUtils.buildEnvVarsWithFieldRef(
           Seq(