YARN-8569. Create an interface to provide cluster information to application. Contributed by Eric Yang

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

@@ -273,7 +273,14 @@ public interface ApplicationConstants {
      * Final, Docker run support ENTRY_POINT.
      */
     YARN_CONTAINER_RUNTIME_DOCKER_RUN_OVERRIDE_DISABLE(
-        "YARN_CONTAINER_RUNTIME_DOCKER_RUN_OVERRIDE_DISABLE");
+        "YARN_CONTAINER_RUNTIME_DOCKER_RUN_OVERRIDE_DISABLE"),
+
+    /**
+     * $YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE
+     * Final, expose cluster information to container.
+     */
+    YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE(
+        "YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE");
 
     private final String variable;
     private Environment(String variable) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/ServiceMaster.java

@@ -45,6 +45,7 @@ import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.security.AMRMTokenIdentifier;
 import org.apache.hadoop.yarn.security.client.ClientToAMTokenSecretManager;
+import org.apache.hadoop.yarn.service.api.records.Service;
 import org.apache.hadoop.yarn.service.api.records.ServiceState;
 import org.apache.hadoop.yarn.service.exceptions.BadClusterStateException;
 import org.apache.hadoop.yarn.service.monitor.ServiceMonitor;
@@ -302,6 +303,12 @@ public class ServiceMaster extends CompositeService {
       LOG.info("Service state changed from {} -> {}", curState,
           scheduler.getApp().getState());
     }
+    populateYarnSysFS(scheduler);
+  }
+
+  private static void populateYarnSysFS(ServiceScheduler scheduler) {
+    Service service = scheduler.getApp();
+    scheduler.syncSysFs(service);
   }
 
   private void printSystemEnv() {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/ServiceScheduler.java

@@ -21,6 +21,9 @@ package org.apache.hadoop.yarn.service;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.sun.jersey.api.client.ClientResponse;
+import com.sun.jersey.api.client.WebResource.Builder;
+
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.hadoop.conf.Configuration;
@@ -38,6 +41,7 @@ import org.apache.hadoop.registry.client.types.yarn.YarnRegistryAttributes;
 import org.apache.hadoop.security.HadoopKerberosName;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.service.CompositeService;
+import org.apache.hadoop.yarn.api.ApplicationConstants;
 import org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
@@ -77,6 +81,7 @@ import org.apache.hadoop.yarn.service.provider.ProviderUtils;
 import org.apache.hadoop.yarn.service.registry.YarnRegistryViewForProviders;
 import org.apache.hadoop.yarn.service.timelineservice.ServiceMetricsSink;
 import org.apache.hadoop.yarn.service.timelineservice.ServiceTimelinePublisher;
+import org.apache.hadoop.yarn.service.utils.HttpUtil;
 import org.apache.hadoop.yarn.service.utils.ServiceApiUtil;
 import org.apache.hadoop.yarn.service.utils.ServiceRegistryUtils;
 import org.apache.hadoop.yarn.service.utils.ServiceUtils;
@@ -90,6 +95,7 @@ import org.slf4j.LoggerFactory;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.URI;
+import java.net.URISyntaxException;
 import java.nio.ByteBuffer;
 import java.text.MessageFormat;
 import java.util.Collection;
@@ -1027,4 +1033,65 @@ public class ServiceScheduler extends CompositeService {
   public ServiceUtils.ProcessTerminationHandler getTerminationHandler() {
     return terminationHandler;
   }
+
+  public void syncSysFs(Service yarnApp) {
+    boolean success = true;
+    Configuration conf = getConfig();
+    String spec;
+    boolean useKerberos = UserGroupInformation.isSecurityEnabled();
+    boolean printSyncResult = false;
+    try {
+      String port = conf.get("yarn.nodemanager.webapp.address").split(":")[1];
+      spec = ServiceApiUtil.jsonSerDeser.toJson(yarnApp);
+      for (org.apache.hadoop.yarn.service.api.records.Component c :
+          yarnApp.getComponents()) {
+        Set<String> nodes = new HashSet<String>();
+        boolean update = Boolean.parseBoolean(c.getConfiguration()
+            .getEnv(ApplicationConstants.Environment
+                .YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE.name()));
+        if (!update) {
+          continue;
+        }
+        printSyncResult = true;
+        for (org.apache.hadoop.yarn.service.api.records.Container container :
+            c.getContainers()) {
+          String bareHost = container.getBareHost();
+          nodes.add(bareHost);
+        }
+        for (String bareHost : nodes) {
+          StringBuilder requestPath = new StringBuilder();
+          if (YarnConfiguration.useHttps(conf)) {
+            requestPath.append("https://");
+          } else {
+            requestPath.append("http://");
+          }
+          requestPath.append(bareHost);
+          requestPath.append(":");
+          requestPath.append(port);
+          requestPath.append("/ws/v1/node/yarn/sysfs/");
+          requestPath.append(UserGroupInformation.getCurrentUser()
+              .getShortUserName());
+          requestPath.append("/");
+          requestPath.append(yarnApp.getId());
+          if (!useKerberos) {
+            requestPath.append("?user.name=");
+            requestPath.append(UserGroupInformation.getCurrentUser()
+                .getShortUserName());
+          }
+          Builder builder = HttpUtil.connect(requestPath.toString());
+          ClientResponse response = builder.put(ClientResponse.class, spec);
+          if (response.getStatus()!=ClientResponse.Status.OK.getStatusCode()) {
+            LOG.warn("Error synchronize YARN sysfs: " +
+                response.getEntity(String.class));
+            success = false;
+          }
+        }
+      }
+      if (printSyncResult && success) {
+        LOG.info("YARN sysfs synchronized.");
+      }
+    } catch (IOException | URISyntaxException | InterruptedException e) {
+      LOG.error("Fail to sync service spec: {}", e);
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/client/ServiceClient.java

@@ -20,10 +20,14 @@ package org.apache.hadoop.yarn.service.client;
 
 import com.google.common.annotations.VisibleForTesting;
 
+import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
+import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
+import org.apache.commons.compress.utils.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.curator.framework.CuratorFramework;
 import org.apache.curator.framework.CuratorFrameworkFactory;
 import org.apache.curator.retry.RetryNTimes;
+import org.apache.curator.shaded.com.google.common.io.Files;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
@@ -73,6 +77,8 @@ import org.apache.hadoop.yarn.service.api.records.ComponentContainers;
 import org.apache.hadoop.yarn.service.api.records.Container;
 import org.apache.hadoop.yarn.service.api.records.ContainerState;
 import org.apache.hadoop.yarn.service.api.records.Component;
+import org.apache.hadoop.yarn.service.api.records.ConfigFile;
+import org.apache.hadoop.yarn.service.api.records.ConfigFile.TypeEnum;
 import org.apache.hadoop.yarn.service.api.records.Service;
 import org.apache.hadoop.yarn.service.api.records.ServiceState;
 import org.apache.hadoop.yarn.service.conf.SliderExitCodes;
@@ -97,12 +103,18 @@ import org.apache.hadoop.yarn.util.Times;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.BufferedOutputStream;
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
 import java.text.MessageFormat;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
@@ -929,6 +941,8 @@ public class ServiceClient extends AppAdminClient implements SliderExitCodes,
     addJarResource(serviceName, localResources);
     // add keytab if in secure env
     addKeytabResourceIfSecure(fs, localResources, app);
+    // add yarn sysfs to localResources
+    addYarnSysFs(appRootDir, localResources, app);
     if (LOG.isDebugEnabled()) {
       printLocalResources(localResources);
     }
@@ -938,8 +952,8 @@ public class ServiceClient extends AppAdminClient implements SliderExitCodes,
     String cmdStr = buildCommandLine(app, conf, appRootDir, hasAMLog4j);
     submissionContext.setResource(Resource.newInstance(YarnServiceConf
         .getLong(YarnServiceConf.AM_RESOURCE_MEM,
-            YarnServiceConf.DEFAULT_KEY_AM_RESOURCE_MEM, app.getConfiguration(),
-            conf), 1));
+            YarnServiceConf.DEFAULT_KEY_AM_RESOURCE_MEM,
+            app.getConfiguration(), conf), 1));
     String queue = app.getQueue();
     if (StringUtils.isEmpty(queue)) {
       queue = conf.get(YARN_QUEUE, DEFAULT_YARN_QUEUE);
@@ -963,6 +977,128 @@ public class ServiceClient extends AppAdminClient implements SliderExitCodes,
     return submissionContext.getApplicationId();
   }
 
+  /**
+   * Compress (tar) the input files to the output file.
+   *
+   * @param files The files to compress
+   * @param output The resulting output file (should end in .tar.gz)
+   * @param bundleRoot
+   * @throws IOException
+   */
+  public static File compressFiles(Collection<File> files, File output,
+      String bundleRoot) throws IOException {
+    try (FileOutputStream fos = new FileOutputStream(output);
+        TarArchiveOutputStream taos = new TarArchiveOutputStream(
+            new BufferedOutputStream(fos))) {
+      taos.setLongFileMode(TarArchiveOutputStream.LONGFILE_GNU);
+      for (File f : files) {
+        addFilesToCompression(taos, f, "sysfs", bundleRoot);
+      }
+    }
+    return output;
+  }
+
+  /**
+   * Compile file list for compression and going recursive for
+   * nested directories.
+   *
+   * @param taos The archive
+   * @param file The file to add to the archive
+   * @param dir The directory that should serve as
+   *            the parent directory in the archive
+   * @throws IOException
+   */
+  private static void addFilesToCompression(TarArchiveOutputStream taos,
+      File file, String dir, String bundleRoot) throws IOException {
+    if (!file.isHidden()) {
+      // Create an entry for the file
+      if (!dir.equals(".")) {
+        if (File.separator.equals("\\")) {
+          dir = dir.replaceAll("\\\\", "/");
+        }
+      }
+      taos.putArchiveEntry(
+          new TarArchiveEntry(file, dir + "/" + file.getName()));
+      if (file.isFile()) {
+        // Add the file to the archive
+        try (FileInputStream input = new FileInputStream(file)) {
+          IOUtils.copy(input, taos);
+          taos.closeArchiveEntry();
+        }
+      } else if (file.isDirectory()) {
+        // close the archive entry
+        if (!dir.equals(".")) {
+          taos.closeArchiveEntry();
+        }
+        // go through all the files in the directory and using recursion, add
+        // them to the archive
+        File[] allFiles = file.listFiles();
+        if (allFiles != null) {
+          for (File childFile : allFiles) {
+            addFilesToCompression(taos, childFile,
+                file.getPath().substring(bundleRoot.length()), bundleRoot);
+          }
+        }
+      }
+    }
+  }
+
+  private void addYarnSysFs(Path path,
+      Map<String, LocalResource> localResources, Service app)
+          throws IOException {
+    List<Component> componentsWithYarnSysFS = new ArrayList<Component>();
+    for(Component c : app.getComponents()) {
+      boolean enabled = Boolean.parseBoolean(c.getConfiguration()
+          .getEnv(ApplicationConstants.Environment
+              .YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE.name()));
+      if (enabled) {
+        componentsWithYarnSysFS.add(c);
+      }
+    }
+    if(componentsWithYarnSysFS.size() == 0) {
+      return;
+    }
+    String buffer = ServiceApiUtil.jsonSerDeser.toJson(app);
+    File tmpDir = Files.createTempDir();
+    if (tmpDir.exists()) {
+      String serviceJsonPath = tmpDir.getAbsolutePath() + "/app.json";
+      File localFile = new File(serviceJsonPath);
+      if (localFile.createNewFile()) {
+        try (Writer writer = new OutputStreamWriter(
+            new FileOutputStream(localFile), StandardCharsets.UTF_8)) {
+          writer.write(buffer);
+        }
+      } else {
+        throw new IOException("Fail to write app.json to temp directory");
+      }
+      File destinationFile = new File(tmpDir.getAbsolutePath() + "/sysfs.tar");
+      if (!destinationFile.createNewFile()) {
+        throw new IOException("Fail to localize sysfs.tar.");
+      }
+      List<File> files = new ArrayList<File>();
+      files.add(localFile);
+      compressFiles(files, destinationFile, "sysfs");
+      LocalResource localResource =
+          fs.submitFile(destinationFile, path, ".", "sysfs.tar");
+      Path serviceJson = new Path(path, "sysfs.tar");
+      for (Component c  : componentsWithYarnSysFS) {
+        ConfigFile e = new ConfigFile();
+        e.type(TypeEnum.ARCHIVE);
+        e.srcFile(serviceJson.toString());
+        e.destFile("/hadoop/yarn");
+        if (!c.getConfiguration().getFiles().contains(e)) {
+          c.getConfiguration().getFiles().add(e);
+        }
+      }
+      localResources.put("sysfs", localResource);
+      if (!tmpDir.delete()) {
+        LOG.warn("Failed to delete temp file: " + tmpDir.getAbsolutePath());
+      }
+    } else {
+      throw new IOException("Fail to localize sysfs resource.");
+    }
+  }
+
   private void setLogAggregationContext(Service app, Configuration conf,
       ApplicationSubmissionContext submissionContext) {
     LogAggregationContext context = Records.newRecord(LogAggregationContext
@@ -1565,4 +1701,5 @@ public class ServiceClient extends AppAdminClient implements SliderExitCodes,
       this.principalName = principalName;
     }
   }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/utils/HttpUtil.java

@@ -0,0 +1,123 @@
+/*
+ * 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.service.utils;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.charset.StandardCharsets;
+import java.security.PrivilegedExceptionAction;
+
+import javax.ws.rs.core.HttpHeaders;
+import javax.ws.rs.core.MediaType;
+
+import org.apache.commons.codec.binary.Base64;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.authentication.client.AuthenticationException;
+import org.apache.hadoop.security.authentication.util.KerberosUtil;
+import org.ietf.jgss.GSSContext;
+import org.ietf.jgss.GSSException;
+import org.ietf.jgss.GSSManager;
+import org.ietf.jgss.GSSName;
+import org.ietf.jgss.Oid;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.sun.jersey.api.client.Client;
+import com.sun.jersey.api.client.WebResource.Builder;
+
+/**
+ * Http connection utilities.
+ *
+ */
+public class HttpUtil {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(HttpUtil.class);
+  private static final Base64 BASE_64_CODEC = new Base64(0);
+
+  protected HttpUtil() {
+    // prevents calls from subclass
+    throw new UnsupportedOperationException();
+  }
+
+  /**
+   * Generate SPNEGO challenge request token.
+   *
+   * @param server - hostname to contact
+   * @throws IOException
+   * @throws InterruptedException
+   */
+  public static String generateToken(String server) throws
+      IOException, InterruptedException {
+    UserGroupInformation currentUser = UserGroupInformation.getCurrentUser();
+    LOG.debug("The user credential is {}", currentUser);
+    String challenge = currentUser
+        .doAs(new PrivilegedExceptionAction<String>() {
+          @Override
+          public String run() throws Exception {
+            try {
+              // This Oid for Kerberos GSS-API mechanism.
+              Oid mechOid = KerberosUtil.getOidInstance("GSS_KRB5_MECH_OID");
+              GSSManager manager = GSSManager.getInstance();
+              // GSS name for server
+              GSSName serverName = manager.createName("HTTP@" + server,
+                  GSSName.NT_HOSTBASED_SERVICE);
+              // Create a GSSContext for authentication with the service.
+              // We're passing client credentials as null since we want them to
+              // be read from the Subject.
+              GSSContext gssContext = manager.createContext(
+                  serverName.canonicalize(mechOid), mechOid, null,
+                  GSSContext.DEFAULT_LIFETIME);
+              gssContext.requestMutualAuth(true);
+              gssContext.requestCredDeleg(true);
+              // Establish context
+              byte[] inToken = new byte[0];
+              byte[] outToken = gssContext.initSecContext(inToken, 0,
+                  inToken.length);
+              gssContext.dispose();
+              // Base64 encoded and stringified token for server
+              LOG.debug("Got valid challenge for host {}", serverName);
+              return new String(BASE_64_CODEC.encode(outToken),
+                  StandardCharsets.US_ASCII);
+            } catch (GSSException | IllegalAccessException
+                | NoSuchFieldException | ClassNotFoundException e) {
+              LOG.error("Error: {}", e);
+              throw new AuthenticationException(e);
+            }
+          }
+        });
+    return challenge;
+  }
+
+  public static Builder connect(String url) throws URISyntaxException,
+      IOException, InterruptedException {
+    boolean useKerberos = UserGroupInformation.isSecurityEnabled();
+    URI resource = new URI(url);
+    Client client = Client.create();
+    Builder builder = client
+        .resource(url).type(MediaType.APPLICATION_JSON);
+    if (useKerberos) {
+      String challenge = generateToken(resource.getHost());
+      builder.header(HttpHeaders.AUTHORIZATION, "Negotiate " +
+          challenge);
+      LOG.debug("Authorization: Negotiate {}", challenge);
+    }
+    return builder;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/main/java/org/apache/hadoop/yarn/service/utils/ServiceApiUtil.java

@@ -95,8 +95,6 @@ public class ServiceApiUtil {
   private static final PatternValidator userNamePattern
       = new PatternValidator("[a-z][a-z0-9-.]*");
 
-
-
   @VisibleForTesting
   public static void setJsonSerDeser(JsonSerDeser jsd) {
     jsonSerDeser = jsd;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-services/hadoop-yarn-services-core/src/test/java/org/apache/hadoop/yarn/service/TestServiceAM.java

@@ -18,7 +18,6 @@
 
 package org.apache.hadoop.yarn.service;
 
-import com.google.common.base.Supplier;
 import com.google.common.collect.ImmutableMap;
 import org.apache.commons.io.FileUtils;
 import org.apache.curator.test.TestingCluster;
@@ -426,4 +425,35 @@ public class TestServiceAM extends ServiceTestUtils{
         am.getComponent("compa").getPendingInstances().size());
     am.stop();
   }
+
+  @Test(timeout = 30000)
+  public void testSyncSysFS() {
+    ApplicationId applicationId = ApplicationId.newInstance(
+        System.currentTimeMillis(), 1);
+    Service exampleApp = new Service();
+    exampleApp.setId(applicationId.toString());
+    exampleApp.setVersion("v1");
+    exampleApp.setName("tensorflow");
+
+    Component compA = createComponent("compa", 1, "pwd");
+    compA.getConfiguration().getEnv().put(
+        "YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE", "true");
+    Artifact artifact = new Artifact();
+    artifact.setType(Artifact.TypeEnum.TARBALL);
+    compA.artifact(artifact);
+    exampleApp.addComponent(compA);
+    try {
+      MockServiceAM am = new MockServiceAM(exampleApp);
+      am.init(conf);
+      am.start();
+      ServiceScheduler scheduler = am.context.scheduler;
+      scheduler.syncSysFs(exampleApp);
+      scheduler.close();
+      am.stop();
+      am.close();
+    } catch (Exception e) {
+      LOG.error("Fail to sync sysfs: {}", e);
+      Assert.fail("Fail to sync sysfs.");
+    }
+  }
 }

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

@@ -258,6 +258,18 @@ public abstract class ContainerExecutor implements Configurable {
   public abstract boolean isContainerAlive(ContainerLivenessContext ctx)
       throws IOException;
 
+  /**
+   * Update cluster information inside container.
+   *
+   * @param ctx ContainerRuntimeContext
+   * @param user Owner of application
+   * @param appId YARN application ID
+   * @param spec Service Specification
+   * @throws IOException if there is a failure while writing spec to disk
+   */
+  public abstract void updateYarnSysFS(Context ctx, String user,
+      String appId, String spec) throws IOException;
+
   /**
    * Recover an already existing container. This is a blocking call and returns
    * only when the container exits.  Note that the container must have been

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

@@ -46,6 +46,7 @@ import org.apache.hadoop.fs.FileUtil;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.UnsupportedFileSystemException;
 import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.service.ServiceStateException;
 import org.apache.hadoop.util.Shell;
 import org.apache.hadoop.util.Shell.CommandExecutor;
 import org.apache.hadoop.util.Shell.ExitCodeException;
@@ -1038,4 +1039,10 @@ public class DefaultContainerExecutor extends ContainerExecutor {
     }
     return paths;
   }
+
+  @Override
+  public void updateYarnSysFS(Context ctx, String user,
+      String appId, String spec) throws IOException {
+    throw new ServiceStateException("Implementation unavailable");
+  }
 }

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

@@ -67,6 +67,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.nio.charset.Charset;
@@ -996,4 +997,46 @@ public class LinuxContainerExecutor extends ContainerExecutor {
           "containerId: {}. Exception: ", containerId, e);
     }
   }
+
+  @Override
+  public synchronized void updateYarnSysFS(Context ctx, String user,
+      String appId, String spec) throws IOException {
+    LocalDirsHandlerService dirsHandler = nmContext.getLocalDirsHandler();
+    Path sysFSPath = dirsHandler.getLocalPathForWrite(
+        "nmPrivate/" + appId + "/sysfs/app.json");
+    File file = new File(sysFSPath.toString());
+    List<String> localDirs = dirsHandler.getLocalDirs();
+    if (file.exists()) {
+      if (!file.delete()) {
+        LOG.warn("Unable to delete " + sysFSPath.toString());
+      }
+    }
+    if (file.createNewFile()) {
+      FileOutputStream output = new FileOutputStream(file);
+      try {
+        output.write(spec.getBytes("UTF-8"));
+      } finally {
+        output.close();
+      }
+    }
+    PrivilegedOperation privOp = new PrivilegedOperation(
+        PrivilegedOperation.OperationType.SYNC_YARN_SYSFS);
+    String runAsUser = getRunAsUser(user);
+    privOp.appendArgs(runAsUser,
+        user,
+        Integer.toString(PrivilegedOperation.RunAsUserCommand
+        .SYNC_YARN_SYSFS.getValue()),
+        appId, StringUtils.join(PrivilegedOperation
+            .LINUX_FILE_PATH_SEPARATOR, localDirs));
+    privOp.disableFailureLogging();
+    PrivilegedOperationExecutor privilegedOperationExecutor =
+        PrivilegedOperationExecutor.getInstance(nmContext.getConf());
+    try {
+      privilegedOperationExecutor.executePrivilegedOperation(null,
+            privOp, null, null, false, false);
+    } catch (PrivilegedOperationException e) {
+      throw new IOException(e);
+    }
+  }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/linux/privileged/PrivilegedOperation.java

@@ -56,7 +56,8 @@ public class PrivilegedOperation {
     LIST_AS_USER(""), // no CLI switch supported yet.
     ADD_NUMA_PARAMS(""), // no CLI switch supported yet.
     REMOVE_DOCKER_CONTAINER("--remove-docker-container"),
-    INSPECT_DOCKER_CONTAINER("--inspect-docker-container");
+    INSPECT_DOCKER_CONTAINER("--inspect-docker-container"),
+    SYNC_YARN_SYSFS("");
 
     private final String option;
 
@@ -153,7 +154,8 @@ public class PrivilegedOperation {
     SIGNAL_CONTAINER(2),
     DELETE_AS_USER(3),
     LAUNCH_DOCKER_CONTAINER(4),
-    LIST_AS_USER(5);
+    LIST_AS_USER(5),
+    SYNC_YARN_SYSFS(6);
 
     private int value;
     RunAsUserCommand(int value) {

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

@@ -179,6 +179,12 @@ import static org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.r
  *     This feature is disabled by default. When this feature is disabled or set
  *     to false, the container will be removed as soon as it exits.
  *   </li>
+ *   <li>
+ *     {@code YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE} allows export yarn
+ *     service json to docker container.  This feature is disabled by default.
+ *     when this feature is set, app.json will be available in
+ *     /hadoop/yarn/sysfs/app.json.
+ *   </li>
  * </ul>
  */
 @InterfaceAudience.Private
@@ -231,6 +237,11 @@ public class DockerLinuxContainerRuntime implements LinuxContainerRuntime {
   @InterfaceAudience.Private
   public static final String ENV_DOCKER_CONTAINER_DELAYED_REMOVAL =
       "YARN_CONTAINER_RUNTIME_DOCKER_DELAYED_REMOVAL";
+  @InterfaceAudience.Private
+  public static final String ENV_DOCKER_CONTAINER_YARN_SYSFS =
+      "YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE";
+  public static final String YARN_SYSFS_PATH =
+      "/hadoop/yarn/sysfs";
   private Configuration conf;
   private Context nmContext;
   private DockerClient dockerClient;
@@ -964,6 +975,12 @@ public class DockerLinuxContainerRuntime implements LinuxContainerRuntime {
 
     addCGroupParentIfRequired(resourcesOpts, containerIdStr, runCommand);
 
+    if(environment.containsKey(ENV_DOCKER_CONTAINER_YARN_SYSFS) &&
+        Boolean.parseBoolean(environment
+            .get(ENV_DOCKER_CONTAINER_YARN_SYSFS))) {
+      runCommand.setYarnSysFS(true);
+    }
+
     if (useEntryPoint) {
       runCommand.setOverrideDisabled(true);
       runCommand.addEnv(environment);
@@ -1438,4 +1455,5 @@ public class DockerLinuxContainerRuntime implements LinuxContainerRuntime {
       }
     }
   }
+
 }

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

@@ -217,4 +217,10 @@ public class DockerRunCommand extends DockerCommand {
   public final void addEnv(Map<String, String> environment) {
     userEnv.putAll(environment);
   }
+
+  public DockerRunCommand setYarnSysFS(boolean toggle) {
+    String value = Boolean.toString(toggle);
+    super.addCommandArguments("use-yarn-sysfs", value);
+    return this;
+  }
 }

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

@@ -38,6 +38,7 @@ import org.slf4j.LoggerFactory;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.ws.rs.GET;
+import javax.ws.rs.PUT;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
@@ -56,6 +57,7 @@ import org.apache.hadoop.classification.InterfaceAudience.Public;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.http.JettyUtils;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.service.ServiceStateException;
 import org.apache.hadoop.yarn.api.records.ApplicationAccessType;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.ContainerId;
@@ -554,6 +556,31 @@ public class NMWebServices {
     return new NMResourceInfo();
   }
 
+  @PUT
+  @Path("/yarn/sysfs/{user}/{appId}")
+  @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
+                MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
+  public Response syncYarnSysFS(@javax.ws.rs.core.Context
+      HttpServletRequest req,
+      @PathParam("user") String user,
+      @PathParam("appId") String appId,
+      String spec) {
+    if (UserGroupInformation.isSecurityEnabled()) {
+      if (!req.getRemoteUser().equals(user)) {
+        return Response.status(Status.FORBIDDEN).build();
+      }
+    }
+    try {
+      nmContext.getContainerExecutor().updateYarnSysFS(nmContext, user, appId,
+          spec);
+    } catch (IOException | ServiceStateException e) {
+      LOG.error("Fail to sync yarn sysfs for application ID: {}, reason: ",
+          appId, e);
+      return Response.status(Status.INTERNAL_SERVER_ERROR).entity(e).build();
+    }
+    return Response.ok().build();
+  }
+
   private long parseLongParam(String bytes) {
     if (bytes == null || bytes.isEmpty()) {
       return Long.MAX_VALUE;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/container-executor.c

@@ -76,6 +76,7 @@ static const char* DEFAULT_BANNED_USERS[] = {"yarn", "mapred", "hdfs", "bin", 0}
 static const int DEFAULT_DOCKER_SUPPORT_ENABLED = 0;
 static const int DEFAULT_TC_SUPPORT_ENABLED = 0;
 static const int DEFAULT_MOUNT_CGROUP_SUPPORT_ENABLED = 0;
+static const int DEFAULT_YARN_SYSFS_SUPPORT_ENABLED = 0;
 
 static const char* PROC_PATH = "/proc";
 
@@ -506,6 +507,11 @@ int is_mount_cgroups_support_enabled() {
                               &executor_cfg);
 }
 
+int is_yarn_sysfs_support_enabled() {
+  return is_feature_enabled(YARN_SYSFS_SUPPORT_ENABLED_KEY,
+                            DEFAULT_YARN_SYSFS_SUPPORT_ENABLED, &executor_cfg);
+}
+
 /**
  * Utility function to concatenate argB to argA using the concat_pattern.
  */
@@ -1778,6 +1784,27 @@ int create_user_filecache_dirs(const char * user, char* const* local_dirs) {
   return rc;
 }
 
+int create_yarn_sysfs(const char* user, const char *app_id,
+    const char *container_id, const char *work_dir, char* const* local_dirs) {
+  int result = OUT_OF_MEMORY;
+  const mode_t perms = S_IRWXU | S_IXGRP;
+  char* const* local_dir_ptr;
+  for(local_dir_ptr = local_dirs; *local_dir_ptr != NULL; ++local_dir_ptr) {
+    char *container_dir = get_container_work_directory(*local_dir_ptr, user, app_id,
+                                                container_id);
+    if (container_dir == NULL) {
+      return OUT_OF_MEMORY;
+    }
+    char *yarn_sysfs_dir = make_string("%s/%s", container_dir, "sysfs");
+    if (mkdir(yarn_sysfs_dir, perms) == 0) {
+      result = 0;
+    }
+    free(yarn_sysfs_dir);
+    free(container_dir);
+  }
+  return result;
+}
+
 int launch_docker_container_as_user(const char * user, const char *app_id,
                               const char *container_id, const char *work_dir,
                               const char *script_name, const char *cred_file,
@@ -1834,6 +1861,14 @@ int launch_docker_container_as_user(const char * user, const char *app_id,
     goto cleanup;
   }
 
+  exit_code = create_yarn_sysfs(user, app_id, container_id, work_dir, local_dirs);
+  if (exit_code != 0) {
+    fprintf(ERRORFILE, "Could not create user yarn sysfs directory");
+    fflush(ERRORFILE);
+    exit(-1);
+    goto cleanup;
+  }
+
   docker_command = construct_docker_command(command_file);
   docker_binary = get_docker_binary(&CFG);
 
@@ -2799,6 +2834,68 @@ struct configuration* get_cfg() {
   return &CFG;
 }
 
+char *locate_sysfs_path(const char *src) {
+  char *result = NULL;
+  DIR *dir;
+  struct dirent *entry;
+  if (!(dir = opendir(src))) {
+    return NULL;
+  }
+  while ((entry = readdir(dir)) != NULL) {
+    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
+      continue;
+    }
+    char *new_src = make_string("%s/%s", src, entry->d_name);
+    if (str_ends_with(new_src, "/sysfs.tar/sysfs")) {
+      result = new_src;
+      goto cleanup;
+    }
+    result = locate_sysfs_path(new_src);
+    if (result != NULL) {
+      goto cleanup;
+    }
+  }
+cleanup:
+  closedir(dir);
+  return result;
+}
+
+int sync_yarn_sysfs(char* const* local_dir, const char *running_user, const char *end_user, const char *app_id) {
+  int result = OUT_OF_MEMORY;
+  char *src = NULL;
+  char *dest = NULL;
+  char* const* local_dir_ptr;
+
+  for(local_dir_ptr = local_dir; *local_dir_ptr != NULL; ++local_dir_ptr) {
+    char *appcache_dir = make_string("%s/usercache/%s/appcache/%s", *local_dir_ptr, end_user, app_id);
+    char *sysfs_dir = locate_sysfs_path(appcache_dir);
+    char *nm_private_app_dir = make_string("%s/nmPrivate/%s/sysfs", *local_dir_ptr, app_id);
+    if (sysfs_dir == NULL) {
+      return OUT_OF_MEMORY;
+    }
+    src = make_string("%s/%s", nm_private_app_dir, "app.json");
+    dest = make_string("%s/%s", sysfs_dir, "app.json");
+    // open up the spec file
+    int spec_file = open_file_as_nm(src);
+    if (spec_file == -1) {
+      continue;
+    }
+
+    delete_path(dest, 0);
+    if (copy_file(spec_file, src, dest, S_IRWXU | S_IRGRP | S_IXGRP) == 0) {
+      result = 0;
+    }
+    // continue on to create other work directories
+    free(sysfs_dir);
+    free(src);
+    free(dest);
+    if (result == 0) {
+      break;
+    }
+  }
+  return result;
+}
+
 /**
  * Flatten docker launch command
  */

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/container-executor.h

@@ -32,7 +32,8 @@ enum command {
   SIGNAL_CONTAINER = 2,
   DELETE_AS_USER = 3,
   LAUNCH_DOCKER_CONTAINER = 4,
-  LIST_AS_USER = 5
+  LIST_AS_USER = 5,
+  SYNC_YARN_SYSFS = 6
 };
 
 enum operations {
@@ -49,7 +50,8 @@ enum operations {
   RUN_DOCKER = 11,
   RUN_AS_USER_LIST = 12,
   REMOVE_DOCKER_CONTAINER = 13,
-  INSPECT_DOCKER_CONTAINER = 14
+  INSPECT_DOCKER_CONTAINER = 14,
+  RUN_AS_USER_SYNC_YARN_SYSFS = 15
 };
 
 #define NM_GROUP_KEY "yarn.nodemanager.linux-container-executor.group"
@@ -67,6 +69,7 @@ enum operations {
 #define DOCKER_SUPPORT_ENABLED_KEY "feature.docker.enabled"
 #define TC_SUPPORT_ENABLED_KEY "feature.tc.enabled"
 #define MOUNT_CGROUP_SUPPORT_ENABLED_KEY "feature.mount-cgroup.enabled"
+#define YARN_SYSFS_SUPPORT_ENABLED_KEY "feature.yarn.sysfs.enabled"
 #define TMP_DIR "tmp"
 
 extern struct passwd *user_detail;
@@ -293,6 +296,21 @@ int run_docker_with_pty(const char *command_file);
  */
 int exec_docker_command(char *docker_command, char **argv, int argc);
 
+/** Check if yarn sysfs is enabled in configuration. */
+int is_yarn_sysfs_support_enabled();
+
+/**
+ * Create YARN SysFS
+ */
+int create_yarn_sysfs(const char* user, const char *app_id,
+    const char *container_id, const char *work_dir, char* const* local_dirs);
+
+/**
+ * Sync YARN SysFS
+ */
+int sync_yarn_sysfs(char* const* local_dirs, const char *running_user,
+    const char *end_user, const char *app_id);
+
 /*
  * Compile the regex_str and determine if the input string matches.
  * Return 0 on match, 1 of non-match.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/main.c

@@ -99,11 +99,21 @@ static void display_usage(FILE *stream) {
     fprintf(stream, "\n");
   }
 
-   fprintf(stream,
+  fprintf(stream,
       "            signal container:      %2d container-pid signal\n"
       "            delete as user:        %2d relative-path\n"
       "            list as user:          %2d relative-path\n",
       SIGNAL_CONTAINER, DELETE_AS_USER, LIST_AS_USER);
+
+  if(is_yarn_sysfs_support_enabled()) {
+    fprintf(stream,
+        "            sync yarn sysfs:       %2d app-id nm-local-dirs\n",
+        SYNC_YARN_SYSFS);
+  } else {
+    fprintf(stream,
+        "[DISABLED]  sync yarn sysfs:       %2d app-id nm-local-dirs\n",
+        SYNC_YARN_SYSFS);
+  }
 }
 
 /* Sets up log files for normal/error logging */
@@ -566,6 +576,11 @@ static int validate_run_as_user_commands(int argc, char **argv, int *operation)
     cmd_input.target_dir = argv[optind++];
     *operation = RUN_AS_USER_LIST;
     return 0;
+  case SYNC_YARN_SYSFS:
+    cmd_input.app_id = argv[optind++];
+    cmd_input.local_dirs = argv[optind++];
+    *operation = RUN_AS_USER_SYNC_YARN_SYSFS;
+    return 0;
   default:
     fprintf(ERRORFILE, "Invalid command %d not supported.",command);
     fflush(ERRORFILE);
@@ -723,6 +738,19 @@ int main(int argc, char **argv) {
 
     exit_code = list_as_user(cmd_input.target_dir);
     break;
+  case RUN_AS_USER_SYNC_YARN_SYSFS:
+    exit_code = set_user(cmd_input.run_as_user_name);
+    if (exit_code != 0) {
+      break;
+    }
+    if (is_yarn_sysfs_support_enabled()) {
+      exit_code = sync_yarn_sysfs(split(cmd_input.local_dirs),
+          cmd_input.run_as_user_name, cmd_input.yarn_user_name,
+          cmd_input.app_id);
+    } else {
+      exit_code = FEATURE_DISABLED;
+    }
+    break;
   }
 
   flush_and_close_log_files();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/utils/string-utils.c

@@ -17,6 +17,9 @@
  */
 #include "util.h"
 
+#include <unistd.h>
+#include <sys/types.h>
+#include <dirent.h>
 #include <limits.h>
 #include <errno.h>
 #include <strings.h>
@@ -180,3 +183,9 @@ char *make_string(const char *fmt, ...) {
   }
   return buf;
 }
+
+int str_ends_with(const char *s, const char *suffix) {
+    size_t slen = strlen(s);
+    size_t suffix_len = strlen(suffix);
+    return suffix_len <= slen && !strcmp(s + slen - suffix_len, suffix);
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/utils/string-utils.h

@@ -38,4 +38,10 @@ int get_numbers_split_by_comma(const char* input, int** numbers, size_t* n_numbe
  * String format utility
  */
 char *make_string(const char *fmt, ...);
+
+/*
+ * Compare string end with a suffix.
+ * return 1 if succeeded
+ */
+int str_ends_with(const char *s, const char *suffix);
 #endif

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/test/test-container-executor.c

@@ -105,6 +105,7 @@ int write_config_file(char *file_name, int banned) {
     fprintf(file, "min.user.id=0\n");
   }
   fprintf(file, "allowed.system.users=allowedUser,daemon\n");
+  fprintf(file, "feature.yarn.sysfs.enabled=1\n");
   fclose(file);
   return 0;
 }
@@ -524,6 +525,63 @@ void test_is_feature_enabled() {
   free_configuration(&exec_cfg);
 }
 
+void test_yarn_sysfs() {
+  char *app_id = "app-1";
+  char *container_id = "container-1";
+  // Test create sysfs without container.
+  int result = create_yarn_sysfs(username, app_id, container_id, "work", local_dirs);
+  if (result == 0) {
+    printf("Should not be able to create yarn sysfs without container directories.\n");
+    exit(1);
+  }
+
+  result = sync_yarn_sysfs(local_dirs, username, username, app_id);
+  if (result == 0) {
+    printf("sync_yarn_sysfs failed.\n");
+    exit(1);
+  }
+
+  // Create container directories and init app.json
+  char* const* local_dir_ptr;
+  for (local_dir_ptr = local_dirs; *local_dir_ptr != 0; ++local_dir_ptr) {
+    char *user_dir = make_string("%s/usercache/%s", *local_dir_ptr, username);
+    if (mkdirs(user_dir, 0750) != 0) {
+      printf("Can not make user directories: %s\n", user_dir);
+      exit(1);
+    }
+    free(user_dir);
+    char *app_dir = make_string("%s/usercache/%s/appcache/%s/%s", *local_dir_ptr, username, app_id);
+    if (mkdirs(app_dir, 0750) != 0) {
+      printf("Can not make app directories: %s\n", app_dir);
+      exit(1);
+    }
+    free(app_dir);
+    // Simulate distributed cache created directory structures.
+    char *cache_dir = make_string("%s/usercache/%s/appcache/%s/filecache/%s/sysfs.tar/sysfs", *local_dir_ptr, username, app_id, container_id);
+    if (mkdirs(cache_dir, 0750) != 0) {
+      printf("Can not make container directories: %s\n", cache_dir);
+      exit(1);
+    }
+    free(cache_dir);
+    char *nm_dir = make_string("%s/nmPrivate/%s/sysfs", *local_dir_ptr, app_id);
+    if (mkdirs(nm_dir, 0750) != 0) {
+      printf("Can not make nmPrivate directories: %s\n", nm_dir);
+      exit(1);
+    }
+    char *sysfs_path = make_string("%s/%s", nm_dir, "app.json");
+    FILE *file = fopen(sysfs_path, "w");
+    fprintf(file, "{}\n");
+    fclose(file);
+    free(nm_dir);
+  }
+
+  result = sync_yarn_sysfs(local_dirs, username, username, app_id);
+  if (result != 0) {
+    printf("sync_yarn_sysfs failed.\n");
+    exit(1);
+  }
+}
+
 void test_delete_user() {
   printf("\nTesting delete_user\n");
   char* app_dir = get_app_directory(TEST_ROOT "/local-1", yarn_username, "app_3");
@@ -1551,6 +1609,9 @@ int main(int argc, char **argv) {
   printf("\nTesting is_feature_enabled()\n");
   test_is_feature_enabled();
 
+  printf("\nTesting yarn sysfs\n");
+  test_yarn_sysfs();
+
   test_check_user(0);
 
   test_cleaning_docker_cgroups();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/TestLinuxContainerExecutor.java

@@ -706,6 +706,17 @@ public class TestLinuxContainerExecutor {
     verify(lce, times(1)).execContainer(ctx);
   }
 
+  @Test
+  public void testUpdateYarnSysFS() throws Exception {
+    String user = System.getProperty("user.name");
+    String appId="app-1";
+    String spec="";
+    Context ctx = mock(Context.class);
+    LinuxContainerExecutor lce = mock(LinuxContainerExecutor.class);
+    lce.updateYarnSysFS(ctx, user, appId, spec);
+    verify(lce, times(1)).updateYarnSysFS(ctx, user, appId, spec);
+  }
+
   private static class TestResourceHandler implements LCEResourcesHandler {
     static Set<ContainerId> postExecContainers = new HashSet<ContainerId>();
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/monitor/TestContainersMonitorResourceChange.java

@@ -128,6 +128,10 @@ public class TestContainersMonitorResourceChange {
         throws IOException {
       return true;
     }
+    @Override
+    public void updateYarnSysFS(Context ctx, String user, String appId,
+        String spec) throws IOException {
+    }
   }
 
   private static class MockContainerEventHandler implements

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

@@ -287,6 +287,7 @@ The following properties are optional:
 | `banned.users` | A comma-separated list of usernames who should not be allowed to launch applications. The default setting is: yarn, mapred, hdfs, and bin. |
 | `allowed.system.users` | A comma-separated list of usernames who should be allowed to launch applications even if their UIDs are below the configured minimum. If a user appears in allowed.system.users and banned.users, the user will be considered banned. |
 | `feature.tc.enabled` | Must be "true" or "false". "false" means traffic control commands are disabled. "true" means traffic control commands are allowed. |
+| `feature.yarn.sysfs.enabled` | Must be "true" or "false". See YARN sysfs support for detail. The default setting is disabled. |
 
 Part of a container-executor.cfg which allows Docker containers to be launched is below:
 
@@ -369,6 +370,7 @@ environment variables in the application's environment:
 | `YARN_CONTAINER_RUNTIME_DOCKER_MOUNTS` | Adds additional volume mounts to the Docker container. The value of the environment variable should be a comma-separated list of mounts. All such mounts must be given as `source:dest[:mode]` and the mode must be "ro" (read-only) or "rw" (read-write) to specify the type of access being requested. If neither is specified, read-write will be  assumed. The mode may include a bind propagation option. In that case, the mode should either be of the form `[option]`, `rw+[option]`, or `ro+[option]`. Valid bind propagation options are shared, rshared, slave, rslave, private, and rprivate. The requested mounts will be validated by container-executor based on the values set in container-executor.cfg for `docker.allowed.ro-mounts` and `docker.allowed.rw-mounts`. |
 | `YARN_CONTAINER_RUNTIME_DOCKER_TMPFS_MOUNTS` | Adds additional tmpfs mounts to the Docker container. The value of the environment variable should be a comma-separated list of absolute mount points within the container. |
 | `YARN_CONTAINER_RUNTIME_DOCKER_DELAYED_REMOVAL` | Allows a user to request delayed deletion of the Docker container on a per container basis. If true, Docker containers will not be removed until the duration defined by yarn.nodemanager.delete.debug-delay-sec has elapsed. Administrators can disable this feature through the yarn-site property yarn.nodemanager.runtime.linux.docker.delayed-removal.allowed. This feature is disabled by default. When this feature is disabled or set to false, the container will be removed as soon as it exits. |
+| `YARN_CONTAINER_RUNTIME_YARN_SYSFS_ENABLE` | Enable mounting of container working directory sysfs sub-directory into Docker container /hadoop/yarn/sysfs.  This is useful for populating cluster information into container. |
 
 The first two are required. The remainder can be set as needed. While
 controlling the container type through environment variables is somewhat less
@@ -767,3 +769,17 @@ In yarn-env.sh, define:
 ```
 export YARN_CONTAINER_RUNTIME_DOCKER_RUN_OVERRIDE_DISABLE=true
 ```
+
+Docker Container YARN SysFS Support
+-----------------------------------
+
+YARN SysFS is a pseudo file system provided by the YARN framework that
+exports information about clustering information to Docker container.
+Cluster information is exported to /hadoop/yarn/sysfs path.  This
+API allows application developer to obtain clustering information
+without external service dependencies.  Custom application master can
+populate cluster information by calling node manager REST API.
+YARN service framework automatically populates cluster information
+to /hadoop/yarn/sysfs/app.json.  For more information about
+YARN service, see: [YARN Service](./yarn-service/Overview.html).
+