TwillContainerMain.java

/*
 * 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.twill.internal.container;

import com.google.common.base.Charsets;
import com.google.common.base.Preconditions;
import com.google.common.io.Files;
import com.google.common.util.concurrent.Service;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
import org.apache.twill.api.LocalFile;
import org.apache.twill.api.RunId;
import org.apache.twill.api.RuntimeSpecification;
import org.apache.twill.api.TwillRunnableSpecification;
import org.apache.twill.api.TwillSpecification;
import org.apache.twill.discovery.ZKDiscoveryService;
import org.apache.twill.internal.Arguments;
import org.apache.twill.internal.BasicTwillContext;
import org.apache.twill.internal.Constants;
import org.apache.twill.internal.ContainerInfo;
import org.apache.twill.internal.EnvContainerInfo;
import org.apache.twill.internal.EnvKeys;
import org.apache.twill.internal.RunIds;
import org.apache.twill.internal.ServiceMain;
import org.apache.twill.internal.json.ArgumentsCodec;
import org.apache.twill.internal.json.TwillSpecificationAdapter;
import org.apache.twill.zookeeper.RetryStrategies;
import org.apache.twill.zookeeper.ZKClient;
import org.apache.twill.zookeeper.ZKClientService;
import org.apache.twill.zookeeper.ZKClientServices;
import org.apache.twill.zookeeper.ZKClients;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.Reader;
import java.util.concurrent.TimeUnit;

/**
 *
 */
public final class TwillContainerMain extends ServiceMain {

  private static final Logger LOG = LoggerFactory.getLogger(TwillContainerMain.class);

  /**
   * Main method for launching a {@link TwillContainerService} which runs
   * a {@link org.apache.twill.api.TwillRunnable}.
   */
  public static void main(final String[] args) throws Exception {
    // Try to load the secure store from localized file, which AM requested RM to localize it for this container.
    loadSecureStore();

    String zkConnectStr = System.getenv(EnvKeys.TWILL_ZK_CONNECT);
    File twillSpecFile = new File(Constants.Files.TWILL_SPEC);
    RunId appRunId = RunIds.fromString(System.getenv(EnvKeys.TWILL_APP_RUN_ID));
    RunId runId = RunIds.fromString(System.getenv(EnvKeys.TWILL_RUN_ID));
    String runnableName = System.getenv(EnvKeys.TWILL_RUNNABLE_NAME);
    int instanceId = Integer.parseInt(System.getenv(EnvKeys.TWILL_INSTANCE_ID));
    int instanceCount = Integer.parseInt(System.getenv(EnvKeys.TWILL_INSTANCE_COUNT));

    ZKClientService zkClientService = ZKClientServices.delegate(
      ZKClients.reWatchOnExpire(
        ZKClients.retryOnFailure(ZKClientService.Builder.of(zkConnectStr).build(),
                                 RetryStrategies.fixDelay(1, TimeUnit.SECONDS))));

    ZKDiscoveryService discoveryService = new ZKDiscoveryService(zkClientService);

    TwillSpecification twillSpec = loadTwillSpec(twillSpecFile);
    renameLocalFiles(twillSpec.getRunnables().get(runnableName));
    
    TwillRunnableSpecification runnableSpec = twillSpec.getRunnables().get(runnableName).getRunnableSpecification();
    ContainerInfo containerInfo = new EnvContainerInfo();
    Arguments arguments = decodeArgs();
    BasicTwillContext context = new BasicTwillContext(
      runId, appRunId, containerInfo.getHost(),
      arguments.getRunnableArguments().get(runnableName).toArray(new String[0]),
      arguments.getArguments().toArray(new String[0]),
      runnableSpec, instanceId, discoveryService, discoveryService, instanceCount,
      containerInfo.getMemoryMB(), containerInfo.getVirtualCores()
    );

    Configuration conf = new YarnConfiguration(new HdfsConfiguration(new Configuration()));
    Service service = new TwillContainerService(context, containerInfo,
                                                getContainerZKClient(zkClientService, appRunId, runnableName),
                                                runId, runnableSpec, getClassLoader(),
                                                createAppLocation(conf));
    new TwillContainerMain().doMain(zkClientService, service);
  }

  private static void loadSecureStore() throws IOException {
    if (!UserGroupInformation.isSecurityEnabled()) {
      return;
    }

    File file = new File(Constants.Files.CREDENTIALS);
    if (file.exists()) {
      Credentials credentials = new Credentials();
      DataInputStream input = new DataInputStream(new FileInputStream(file));
      try {
        credentials.readTokenStorageStream(input);
      } finally {
        input.close();
      }

      UserGroupInformation.getCurrentUser().addCredentials(credentials);
      LOG.info("Secure store updated from {}", file);
    }
  }

  private static void renameLocalFiles(RuntimeSpecification runtimeSpec) {
    for (LocalFile file : runtimeSpec.getLocalFiles()) {
      if (file.isArchive()) {
        String path = file.getURI().toString();
        String name = file.getName() + (path.endsWith(".tar.gz") ? ".tar.gz" : path.substring(path.lastIndexOf('.')));
        Preconditions.checkState(new File(name).renameTo(new File(file.getName())),
                                 "Fail to rename file from %s to %s.",
                                 name, file.getName());
      }
    }
  }

  private static ZKClient getContainerZKClient(ZKClient zkClient, RunId appRunId, String runnableName) {
    return ZKClients.namespace(zkClient, String.format("/%s/runnables/%s", appRunId, runnableName));
  }

  /**
   * Returns the ClassLoader for the runnable.
   */
  private static ClassLoader getClassLoader() {
    ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
    if (classLoader == null) {
      return ClassLoader.getSystemClassLoader();
    }
    return classLoader;
  }

  private static TwillSpecification loadTwillSpec(File specFile) throws IOException {
    Reader reader = Files.newReader(specFile, Charsets.UTF_8);
    try {
      return TwillSpecificationAdapter.create().fromJson(reader);
    } finally {
      reader.close();
    }
  }

  private static Arguments decodeArgs() throws IOException {
    return ArgumentsCodec.decode(Files.newReaderSupplier(new File(Constants.Files.ARGUMENTS), Charsets.UTF_8));
  }

  @Override
  protected String getHostname() {
    return System.getenv(EnvKeys.YARN_CONTAINER_HOST);
  }

  @Override
  protected String getKafkaZKConnect() {
    return System.getenv(EnvKeys.TWILL_LOG_KAFKA_ZK);
  }
}