[SPARK-24428][K8S] Fix unused code

## What changes were proposed in this pull request?

Remove code that is misleading and is a leftover from a previous implementation.

## How was this patch tested?
Manually.

Author: Stavros Kontopoulos <stavros.kontopoulos@lightbend.com>

Closes #21462 from skonto/fix-k8s-docs.

Author: Stavros Kontopoulos

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

@@ -25,9 +25,6 @@ private[spark] object Constants {
   val SPARK_POD_DRIVER_ROLE = "driver"
   val SPARK_POD_EXECUTOR_ROLE = "executor"
 
-  // Annotations
-  val SPARK_APP_NAME_ANNOTATION = "spark-app-name"
-
   // Credentials secrets
   val DRIVER_CREDENTIALS_SECRETS_BASE_DIR =
     "/mnt/secrets/spark-kubernetes-credentials"
@@ -50,17 +47,14 @@ private[spark] object Constants {
   val DEFAULT_BLOCKMANAGER_PORT = 7079
   val DRIVER_PORT_NAME = "driver-rpc-port"
   val BLOCK_MANAGER_PORT_NAME = "blockmanager"
-  val EXECUTOR_PORT_NAME = "executor"
 
   // Environment Variables
-  val ENV_EXECUTOR_PORT = "SPARK_EXECUTOR_PORT"
   val ENV_DRIVER_URL = "SPARK_DRIVER_URL"
   val ENV_EXECUTOR_CORES = "SPARK_EXECUTOR_CORES"
   val ENV_EXECUTOR_MEMORY = "SPARK_EXECUTOR_MEMORY"
   val ENV_APPLICATION_ID = "SPARK_APPLICATION_ID"
   val ENV_EXECUTOR_ID = "SPARK_EXECUTOR_ID"
   val ENV_EXECUTOR_POD_IP = "SPARK_EXECUTOR_POD_IP"
-  val ENV_MOUNTED_CLASSPATH = "SPARK_MOUNTED_CLASSPATH"
   val ENV_JAVA_OPT_PREFIX = "SPARK_JAVA_OPT_"
   val ENV_CLASSPATH = "SPARK_CLASSPATH"
   val ENV_DRIVER_BIND_ADDRESS = "SPARK_DRIVER_BIND_ADDRESS"

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/scheduler/cluster/k8s/KubernetesClusterManager.scala

@@ -48,8 +48,6 @@ private[spark] class KubernetesClusterManager extends ExternalClusterManager wit
       sc: SparkContext,
       masterURL: String,
       scheduler: TaskScheduler): SchedulerBackend = {
-    val executorSecretNamesToMountPaths = KubernetesUtils.parsePrefixedKeyValuePairs(
-      sc.conf, KUBERNETES_EXECUTOR_SECRETS_PREFIX)
     val kubernetesClient = SparkKubernetesClientFactory.createKubernetesClient(
       KUBERNETES_MASTER_INTERNAL_URL,
       Some(sc.conf.get(KUBERNETES_NAMESPACE)),

resource-managers/kubernetes/docker/src/main/dockerfiles/spark/entrypoint.sh

@@ -51,12 +51,10 @@ esac
 
 SPARK_CLASSPATH="$SPARK_CLASSPATH:${SPARK_HOME}/jars/*"
 env | grep SPARK_JAVA_OPT_ | sort -t_ -k4 -n | sed 's/[^=]*=\(.*\)/\1/g' > /tmp/java_opts.txt
-readarray -t SPARK_JAVA_OPTS < /tmp/java_opts.txt
-if [ -n "$SPARK_MOUNTED_CLASSPATH" ]; then
-  SPARK_CLASSPATH="$SPARK_CLASSPATH:$SPARK_MOUNTED_CLASSPATH"
-fi
-if [ -n "$SPARK_MOUNTED_FILES_DIR" ]; then
-  cp -R "$SPARK_MOUNTED_FILES_DIR/." .
+readarray -t SPARK_EXECUTOR_JAVA_OPTS < /tmp/java_opts.txt
+
+if [ -n "$SPARK_EXTRA_CLASSPATH" ]; then
+  SPARK_CLASSPATH="$SPARK_CLASSPATH:$SPARK_EXTRA_CLASSPATH"
 fi
 
 if [ -n "$PYSPARK_FILES" ]; then
@@ -101,7 +99,7 @@ case "$SPARK_K8S_CMD" in
   executor)
     CMD=(
       ${JAVA_HOME}/bin/java
-      "${SPARK_JAVA_OPTS[@]}"
+      "${SPARK_EXECUTOR_JAVA_OPTS[@]}"
       -Xms$SPARK_EXECUTOR_MEMORY
       -Xmx$SPARK_EXECUTOR_MEMORY
       -cp "$SPARK_CLASSPATH"