content: /*
   * 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.kafka.connect.cli;
  
  import org.apache.kafka.common.utils.Time;
  import org.apache.kafka.connect.connector.policy.ConnectorClientConfigOverridePolicy;
  import org.apache.kafka.connect.json.JsonConverter;
  import org.apache.kafka.connect.json.JsonConverterConfig;
  import org.apache.kafka.connect.runtime.Worker;
  import org.apache.kafka.connect.runtime.WorkerConfigTransformer;
  import org.apache.kafka.connect.runtime.distributed.DistributedConfig;
  import org.apache.kafka.connect.runtime.distributed.DistributedHerder;
  import org.apache.kafka.connect.runtime.isolation.Plugins;
  import org.apache.kafka.connect.runtime.rest.RestClient;
  import org.apache.kafka.connect.runtime.rest.RestServer;
  import org.apache.kafka.connect.storage.ConfigBackingStore;
  import org.apache.kafka.connect.storage.Converter;
  import org.apache.kafka.connect.storage.KafkaConfigBackingStore;
  import org.apache.kafka.connect.storage.KafkaOffsetBackingStore;
  import org.apache.kafka.connect.storage.KafkaStatusBackingStore;
  import org.apache.kafka.connect.storage.StatusBackingStore;
  import org.apache.kafka.connect.util.ConnectUtils;
  import org.apache.kafka.connect.util.SharedTopicAdmin;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  import static org.apache.kafka.clients.CommonClientConfigs.CLIENT_ID_CONFIG;
  
  /**
   * <p>
   * Command line utility that runs Kafka Connect in distributed mode. In this mode, the process joins a group of other
   * workers and work (connectors and tasks) is distributed among them. This is useful for running Connect as a service,
   * where connectors can be submitted to the cluster to be automatically executed in a scalable, distributed fashion.
   * This also allows you to easily scale out horizontally, elastically adding or removing capacity simply by starting or
   * stopping worker instances.
   * </p>
   */
  public class ConnectDistributed extends AbstractConnectCli<DistributedHerder, DistributedConfig> {
  
      public ConnectDistributed(String... args) {
          super(args);
      }
  
      @Override
      protected String usage() {
          return "ConnectDistributed worker.properties";
      }
  
      @Override
      protected DistributedHerder createHerder(DistributedConfig config, String workerId, Plugins plugins,
                                    ConnectorClientConfigOverridePolicy connectorClientConfigOverridePolicy,
                                    RestServer restServer, RestClient restClient) {
  
          String kafkaClusterId = config.kafkaClusterId();
          String clientIdBase = ConnectUtils.clientIdBase(config);
          // Create the admin client to be shared by all backing stores.
          Map<String, Object> adminProps = new HashMap<>(config.originals());
          ConnectUtils.addMetricsContextProperties(adminProps, config, kafkaClusterId);
          adminProps.put(CLIENT_ID_CONFIG, clientIdBase + "shared-admin");
          SharedTopicAdmin sharedAdmin = new SharedTopicAdmin(adminProps);
  
          KafkaOffsetBackingStore offsetBackingStore = new KafkaOffsetBackingStore(sharedAdmin, () -> clientIdBase,
                  plugins.newInternalConverter(true, JsonConverter.class.getName(),
                          Collections.singletonMap(JsonConverterConfig.SCHEMAS_ENABLE_CONFIG, "false")));
          offsetBackingStore.configure(config);
  
          Worker worker = new Worker(workerId, Time.SYSTEM, plugins, config, offsetBackingStore, connectorClientConfigOverridePolicy);
          WorkerConfigTransformer configTransformer = worker.configTransformer();
  
          Converter internalValueConverter = worker.getInternalValueConverter();
          StatusBackingStore statusBackingStore = new KafkaStatusBackingStore(Time.SYSTEM, internalValueConverter, sharedAdmin, clientIdBase);
          statusBackingStore.configure(config);
  
          ConfigBackingStore configBackingStore = new KafkaConfigBackingStore(
                  internalValueConverter,
                  config,
                  configTransformer,
                  sharedAdmin,
                  clientIdBase);
  
          // Pass the shared admin to the distributed herder as an additional AutoCloseable object that should be closed when the
          // herder is stopped. This is easier than having to track and own the lifecycle ourselves.
          return new DistributedHerder(config, Time.SYSTEM, worker,
                  kafkaClusterId, statusBackingStore, configBackingStore,
                  restServer.advertisedUrl().toString(), restClient, connectorClientConfigOverridePolicy,
                  Collections.emptyList(), sharedAdmin);
      }
  
      @Override
      protected DistributedConfig createConfig(Map<String, String> workerProps) {
          return new DistributedConfig(workerProps);
      }
  
      public static void main(String[] args) {
          ConnectDistributed connectDistributed = new ConnectDistributed(args);
          connectDistributed.run();
      }
  }
  