YARN-6930. Admins should be able to explicitly enable specific LinuxContainerRuntime in the NodeManager. Contributed by Shane Kumpf

(cherry picked from commit b0b535d9d5)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java

@@ -1464,6 +1464,23 @@ public class YarnConfiguration extends Configuration {
   /** Prefix for runtime configuration constants. */
   public static final String LINUX_CONTAINER_RUNTIME_PREFIX = NM_PREFIX +
       "runtime.linux.";
+
+  /**
+   * Comma separated list of runtimes that are allowed when using
+   * LinuxContainerExecutor. The allowed values are:
+   * <ul>
+   *   <li>default</li>
+   *   <li>docker</li>
+   *   <li>javasandbox</li>
+   * </ul>
+   */
+  public static final String LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES =
+      LINUX_CONTAINER_RUNTIME_PREFIX + "allowed-runtimes";
+
+  /** The default list of allowed runtimes when using LinuxContainerExecutor. */
+  public static final String[] DEFAULT_LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES
+      = {"default"};
+
   public static final String DOCKER_CONTAINER_RUNTIME_PREFIX =
       LINUX_CONTAINER_RUNTIME_PREFIX + "docker.";
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml

@@ -1571,6 +1571,14 @@
     <value>false</value>
   </property>
 
+  <property>
+    <description>Comma separated list of runtimes that are allowed when using
+    LinuxContainerExecutor. The allowed values are default, docker, and
+    javasandbox.</description>
+    <name>yarn.nodemanager.runtime.linux.allowed-runtimes</name>
+    <value>default</value>
+  </property>
+
   <property>
     <description>This configuration setting determines the capabilities
       assigned to docker containers when they are launched. While these may not

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

@@ -51,6 +51,7 @@ import org.apache.hadoop.yarn.exceptions.ConfigurationException;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.ContainerDiagnosticsUpdateEvent;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.runtime.ContainerExecutionException;
 import org.apache.hadoop.yarn.server.nodemanager.executor.ContainerPrepareContext;
 import org.apache.hadoop.yarn.server.nodemanager.util.NodeManagerHardwareUtils;
 import org.apache.hadoop.yarn.server.nodemanager.executor.ContainerLivenessContext;
@@ -663,7 +664,8 @@ public abstract class ContainerExecutor implements Configurable {
   }
 
   // LinuxContainerExecutor overrides this method and behaves differently.
-  public String[] getIpAndHost(Container container) {
+  public String[] getIpAndHost(Container container)
+      throws ContainerExecutionException {
     return getLocalIpAndHost(container);
   }
 

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

@@ -625,7 +625,8 @@ public class LinuxContainerExecutor extends ContainerExecutor {
   }
 
   @Override
-  public String[] getIpAndHost(Container container) {
+  public String[] getIpAndHost(Container container)
+      throws ContainerExecutionException {
     return linuxContainerRuntime.getIpAndHost(container);
   }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/DelegatingLinuxContainerRuntime.java

@@ -20,9 +20,11 @@
 
 package org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.runtime;
 
+import com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.privileged.PrivilegedOperationExecutor;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.runtime.ContainerExecutionException;
@@ -31,6 +33,7 @@ import org.apache.hadoop.yarn.server.nodemanager.containermanager.runtime.Contai
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.EnumSet;
 import java.util.Map;
 
 /**
@@ -50,34 +53,62 @@ public class DelegatingLinuxContainerRuntime implements LinuxContainerRuntime {
   private DefaultLinuxContainerRuntime defaultLinuxContainerRuntime;
   private DockerLinuxContainerRuntime dockerLinuxContainerRuntime;
   private JavaSandboxLinuxContainerRuntime javaSandboxLinuxContainerRuntime;
+  private EnumSet<LinuxContainerRuntimeConstants.RuntimeType> allowedRuntimes =
+      EnumSet.noneOf(LinuxContainerRuntimeConstants.RuntimeType.class);
 
   @Override
   public void initialize(Configuration conf)
       throws ContainerExecutionException {
-    PrivilegedOperationExecutor privilegedOperationExecutor =
+    String[] configuredRuntimes = conf.getTrimmedStrings(
-        PrivilegedOperationExecutor.getInstance(conf);
+        YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
-    defaultLinuxContainerRuntime = new DefaultLinuxContainerRuntime(
+        YarnConfiguration.DEFAULT_LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES);
-        privilegedOperationExecutor);
+    for (String configuredRuntime : configuredRuntimes) {
-    defaultLinuxContainerRuntime.initialize(conf);
+      try {
-    dockerLinuxContainerRuntime = new DockerLinuxContainerRuntime(
+        allowedRuntimes.add(
-        privilegedOperationExecutor);
+            LinuxContainerRuntimeConstants.RuntimeType.valueOf(
-    dockerLinuxContainerRuntime.initialize(conf);
+                configuredRuntime.toUpperCase()));
-    javaSandboxLinuxContainerRuntime = new JavaSandboxLinuxContainerRuntime(
+      } catch (IllegalArgumentException e) {
-        privilegedOperationExecutor);
+        throw new ContainerExecutionException("Invalid runtime set in "
-    javaSandboxLinuxContainerRuntime.initialize(conf);
+            + YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES + " : "
+            + configuredRuntime);
+      }
+    }
+    if (isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.JAVASANDBOX)) {
+      javaSandboxLinuxContainerRuntime = new JavaSandboxLinuxContainerRuntime(
+          PrivilegedOperationExecutor.getInstance(conf));
+      javaSandboxLinuxContainerRuntime.initialize(conf);
+    }
+    if (isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DOCKER)) {
+      dockerLinuxContainerRuntime = new DockerLinuxContainerRuntime(
+          PrivilegedOperationExecutor.getInstance(conf));
+      dockerLinuxContainerRuntime.initialize(conf);
+    }
+    if (isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DEFAULT)) {
+      defaultLinuxContainerRuntime = new DefaultLinuxContainerRuntime(
+          PrivilegedOperationExecutor.getInstance(conf));
+      defaultLinuxContainerRuntime.initialize(conf);
+    }
   }
 
-  private LinuxContainerRuntime pickContainerRuntime(
+  @VisibleForTesting
-      Map<String, String> environment){
+  LinuxContainerRuntime pickContainerRuntime(
+      Map<String, String> environment) throws ContainerExecutionException {
     LinuxContainerRuntime runtime;
     //Sandbox checked first to ensure DockerRuntime doesn't circumvent controls
-    if (javaSandboxLinuxContainerRuntime.isSandboxContainerRequested()){
+    if (javaSandboxLinuxContainerRuntime != null &&
-        runtime = javaSandboxLinuxContainerRuntime;
+        javaSandboxLinuxContainerRuntime.isSandboxContainerRequested()){
-    } else if (DockerLinuxContainerRuntime
+      runtime = javaSandboxLinuxContainerRuntime;
-        .isDockerContainerRequested(environment)){
+    } else if (dockerLinuxContainerRuntime != null &&
+        DockerLinuxContainerRuntime.isDockerContainerRequested(environment)){
       runtime = dockerLinuxContainerRuntime;
-    } else {
+    } else if (defaultLinuxContainerRuntime != null &&
+        !DockerLinuxContainerRuntime.isDockerContainerRequested(environment)) {
       runtime = defaultLinuxContainerRuntime;
+    } else {
+      throw new ContainerExecutionException("Requested runtime not allowed.");
     }
 
     if (LOG.isDebugEnabled()) {
@@ -88,7 +119,8 @@ public class DelegatingLinuxContainerRuntime implements LinuxContainerRuntime {
     return runtime;
   }
 
-  private LinuxContainerRuntime pickContainerRuntime(Container container) {
+  private LinuxContainerRuntime pickContainerRuntime(Container container)
+      throws ContainerExecutionException {
     return pickContainerRuntime(container.getLaunchContext().getEnvironment());
   }
 
@@ -127,8 +159,15 @@ public class DelegatingLinuxContainerRuntime implements LinuxContainerRuntime {
   }
 
   @Override
-  public String[] getIpAndHost(Container container) {
+  public String[] getIpAndHost(Container container)
+      throws ContainerExecutionException {
     LinuxContainerRuntime runtime = pickContainerRuntime(container);
     return runtime.getIpAndHost(container);
   }
+
+  @VisibleForTesting
+  boolean isRuntimeAllowed(
+      LinuxContainerRuntimeConstants.RuntimeType runtimeType) {
+    return allowedRuntimes.contains(runtimeType);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/LinuxContainerRuntimeConstants.java

@@ -31,6 +31,15 @@ public final class LinuxContainerRuntimeConstants {
   private LinuxContainerRuntimeConstants() {
   }
 
+  /**
+   * Linux container runtime types for {@link DelegatingLinuxContainerRuntime}.
+   */
+  public enum RuntimeType {
+    DEFAULT,
+    DOCKER,
+    JAVASANDBOX;
+  }
+
   public static final Attribute<Map> LOCALIZED_RESOURCES = Attribute
       .attribute(Map.class, "localized_resources");
   public static final Attribute<List> CONTAINER_LAUNCH_PREFIX_COMMANDS =

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/monitor/ContainersMonitorImpl.java

@@ -38,6 +38,7 @@ import org.apache.hadoop.yarn.server.nodemanager.Context;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.ContainerImpl;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.ContainerKillEvent;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.runtime.ContainerExecutionException;
 import org.apache.hadoop.yarn.server.nodemanager.timelineservice.NMTimelinePublisher;
 import org.apache.hadoop.yarn.server.nodemanager.util.NodeManagerHardwareUtils;
 import org.apache.hadoop.yarn.util.ResourceCalculatorPlugin;
@@ -502,7 +503,8 @@ public class ContainersMonitorImpl extends AbstractService implements
      * @param entry process tree entry to fill in
      */
     private void initializeProcessTrees(
-            Entry<ContainerId, ProcessTreeInfo> entry) {
+            Entry<ContainerId, ProcessTreeInfo> entry)
+        throws ContainerExecutionException {
       ContainerId containerId = entry.getKey();
       ProcessTreeInfo ptInfo = entry.getValue();
       String pId = ptInfo.getPID();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/runtime/ContainerRuntime.java

@@ -77,6 +77,10 @@ public interface ContainerRuntime {
 
   /**
    * Return the host and ip of the container
+   *
+   * @param container the {@link Container}
+   * @throws ContainerExecutionException if an error occurs while getting the ip
+   * and hostname
    */
-  String[] getIpAndHost(Container container);
+  String[] getIpAndHost(Container container) throws ContainerExecutionException;
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/runtime/TestDelegatingLinuxContainerRuntime.java

@@ -0,0 +1,137 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.runtime;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.runtime.ContainerRuntime;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.runtime.ContainerRuntimeConstants;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test container runtime delegation.
+ */
+public class TestDelegatingLinuxContainerRuntime {
+
+  private DelegatingLinuxContainerRuntime delegatingLinuxContainerRuntime;
+  private Configuration conf;
+  private Map<String, String> env = new HashMap<>();
+
+  @Before
+  public void setUp() throws Exception {
+    delegatingLinuxContainerRuntime = new DelegatingLinuxContainerRuntime();
+    conf = new Configuration();
+    env.clear();
+  }
+
+  @Test
+  public void testIsRuntimeAllowedDefault() throws Exception {
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        YarnConfiguration.DEFAULT_LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES[0]);
+    System.out.println(conf.get(
+        YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES));
+    delegatingLinuxContainerRuntime.initialize(conf);
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DEFAULT));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DOCKER));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.JAVASANDBOX));
+  }
+
+  @Test
+  public void testIsRuntimeAllowedDocker() throws Exception {
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        "docker");
+    delegatingLinuxContainerRuntime.initialize(conf);
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DOCKER));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DEFAULT));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.JAVASANDBOX));
+  }
+
+  @Test
+  public void testIsRuntimeAllowedJavaSandbox() throws Exception {
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        "javasandbox");
+    delegatingLinuxContainerRuntime.initialize(conf);
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.JAVASANDBOX));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DEFAULT));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DOCKER));
+  }
+
+  @Test
+  public void testIsRuntimeAllowedMultiple() throws Exception {
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        "docker,javasandbox");
+    delegatingLinuxContainerRuntime.initialize(conf);
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DOCKER));
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.JAVASANDBOX));
+    assertFalse(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DEFAULT));
+  }
+
+  @Test
+  public void testIsRuntimeAllowedAll() throws Exception {
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        "default,docker,javasandbox");
+    delegatingLinuxContainerRuntime.initialize(conf);
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DEFAULT));
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.DOCKER));
+    assertTrue(delegatingLinuxContainerRuntime.isRuntimeAllowed(
+        LinuxContainerRuntimeConstants.RuntimeType.JAVASANDBOX));
+  }
+
+  @Test
+  public void testJavaSandboxNotAllowedButPermissive() throws Exception {
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        "default,docker");
+    conf.set(YarnConfiguration.YARN_CONTAINER_SANDBOX, "permissive");
+    delegatingLinuxContainerRuntime.initialize(conf);
+    ContainerRuntime runtime =
+        delegatingLinuxContainerRuntime.pickContainerRuntime(env);
+    assertTrue(runtime instanceof DefaultLinuxContainerRuntime);
+  }
+
+  @Test
+  public void testJavaSandboxNotAllowedButPermissiveDockerRequested()
+      throws Exception {
+    env.put(ContainerRuntimeConstants.ENV_CONTAINER_TYPE, "docker");
+    conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
+        "default,docker");
+    conf.set(YarnConfiguration.YARN_CONTAINER_SANDBOX, "permissive");
+    delegatingLinuxContainerRuntime.initialize(conf);
+    ContainerRuntime runtime =
+        delegatingLinuxContainerRuntime.pickContainerRuntime(env);
+    assertTrue(runtime instanceof DockerLinuxContainerRuntime);
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/DockerContainers.md

@@ -71,68 +71,83 @@ request. For example:
 The following properties should be set in yarn-site.xml:
 
 ```xml
-<property>
+<configuration>
-  <name>yarn.nodemanager.container-executor.class</name>
+  <property>
-  <value>org.apache.hadoop.yarn.server.nodemanager.LinuxContainerExecutor</value>
+    <name>yarn.nodemanager.container-executor.class</name>
-  <description>
+    <value>org.apache.hadoop.yarn.server.nodemanager.LinuxContainerExecutor</value>
-    This is the container executor setting that ensures that all applications
+    <description>
-    are started with the LinuxContainerExecutor.
+      This is the container executor setting that ensures that all applications
-  </description>
+      are started with the LinuxContainerExecutor.
-</property>
+    </description>
+  </property>
 
-<property>
+  <property>
-  <name>yarn.nodemanager.linux-container-executor.group</name>
+    <name>yarn.nodemanager.linux-container-executor.group</name>
-  <value>hadoop</value>
+    <value>hadoop</value>
-  <description>
+    <description>
-    The POSIX group of the NodeManager. It should match the setting in
+      The POSIX group of the NodeManager. It should match the setting in
-    "container-executor.cfg". This configuration is required for validating
+      "container-executor.cfg". This configuration is required for validating
-    the secure access of the container-executor binary.
+      the secure access of the container-executor binary.
-  </description>
+    </description>
-</property>
+  </property>
 
-<property>
+  <property>
-  <name>yarn.nodemanager.linux-container-executor.nonsecure-mode.limit-users</name>
+    <name>yarn.nodemanager.linux-container-executor.nonsecure-mode.limit-users</name>
-  <value>false</value>
+    <value>false</value>
-  <description>
+    <description>
-    Whether all applications should be run as the NodeManager process' owner.
+      Whether all applications should be run as the NodeManager process' owner.
-    When false, applications are launched instead as the application owner.
+      When false, applications are launched instead as the application owner.
-  </description>
+    </description>
-</property>
+  </property>
 
-<property>
+  <property>
-  <name>yarn.nodemanager.runtime.linux.docker.allowed-container-networks</name>
+    <name>yarn.nodemanager.runtime.linux.allowed-runtimes</name>
-  <value>host,none,bridge</value>
+    <value>default,docker</value>
-  <description>
+    <description>
-    Optional. A comma-separated set of networks allowed when launching
+      Comma separated list of runtimes that are allowed when using
-    containers. Valid values are determined by Docker networks available from
+      LinuxContainerExecutor. The allowed values are default, docker, and
-    `docker network ls`
+      javasandbox.
-  </description>
+    </description>
-</property>
+  </property>
 
-<property>
+  <property>
-  <description>The network used when launching Docker containers when no
+    <name>yarn.nodemanager.runtime.linux.docker.allowed-container-networks</name>
-    network is specified in the request. This network must be one of the
+    <value>host,none,bridge</value>
-    (configurable) set of allowed container networks.</description>
+    <description>
-  <name>yarn.nodemanager.runtime.linux.docker.default-container-network</name>
+      Optional. A comma-separated set of networks allowed when launching
-  <value>host</value>
+      containers. Valid values are determined by Docker networks available from
-</property>
+      `docker network ls`
+    </description>
+  </property>
 
-<property>
+  <property>
-  <name>yarn.nodemanager.runtime.linux.docker.privileged-containers.allowed</name>
+    <name>yarn.nodemanager.runtime.linux.docker.default-container-network</name>
-  <value>false</value>
+    <value>host</value>
-  <description>
+    <description>
-    Optional. Whether applications are allowed to run in privileged containers.
+      The network used when launching Docker containers when no
-  </description>
+      network is specified in the request. This network must be one of the
-</property>
+      (configurable) set of allowed container networks.
+    </description>
+  </property>
 
-<property>
+  <property>
-  <name>yarn.nodemanager.runtime.linux.docker.privileged-containers.acl</name>
+    <name>yarn.nodemanager.runtime.linux.docker.privileged-containers.allowed</name>
-  <value></value>
+    <value>false</value>
-  <description>
+    <description>
-    Optional. A comma-separated list of users who are allowed to request
+      Optional. Whether applications are allowed to run in privileged
-    privileged contains if privileged containers are allowed.
+      containers.
-  </description>
+    </description>
-</property>
+  </property>
+
+  <property>
+    <name>yarn.nodemanager.runtime.linux.docker.privileged-containers.acl</name>
+    <value></value>
+    <description>
+      Optional. A comma-separated list of users who are allowed to request
+      privileged contains if privileged containers are allowed.
+    </description>
+  </property>
+</configuration>
 ```
 
 In addition, a container-executer.cfg file must exist and contain settings for