YARN-9391. Fixed node manager environment leaks into Docker containers.

            Contributed by Jim Brennan

(cherry picked from commit 3c45762a0bfb403e069a03e30d35dd11432ee8b0)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerExecutor.java

@@ -403,16 +403,6 @@ public abstract class ContainerExecutor implements Configurable {
           sb.env(env.getKey(), env.getValue());
         }
       }
-      // Add the whitelist vars to the environment.  Do this after writing
-      // environment variables so they are not written twice.
-      for(String var : whitelistVars) {
-        if (!environment.containsKey(var)) {
-          String val = getNMEnvVar(var);
-          if (val != null) {
-            environment.put(var, val);
-          }
-        }
-      }
     }
 
     if (resources != null) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/TestContainerLaunch.java

@@ -468,10 +468,15 @@ public class TestContainerLaunch extends BaseContainerManagerTest {
     for (String envVar : env.keySet()) {
       Assert.assertTrue(shellContent.contains(envVar + "="));
     }
+    // The whitelist vars should not have been added to env
+    // They should only be in the launch script
     for (String wlVar : whitelistVars) {
+      Assert.assertFalse(env.containsKey(wlVar));
       Assert.assertTrue(shellContent.contains(wlVar + "="));
     }
+    // Non-whitelist nm vars should be in neither env nor in launch script
     for (String nwlVar : nonWhiteListEnv) {
+      Assert.assertFalse(env.containsKey(nwlVar));
       Assert.assertFalse(shellContent.contains(nwlVar + "="));
     }
     // Explicitly Set NM vars should be before user vars