code: /*
   * 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.skywalking.oap.server.cluster.plugin.consul;
  
  import com.google.common.net.HostAndPort;
  import com.orbitz.consul.Consul;
  import com.orbitz.consul.ConsulException;
  import java.util.ArrayList;
  import java.util.List;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.skywalking.oap.server.core.CoreModule;
  import org.apache.skywalking.oap.server.core.cluster.ClusterCoordinator;
  import org.apache.skywalking.oap.server.core.cluster.ClusterModule;
  import org.apache.skywalking.oap.server.core.cluster.ClusterNodesQuery;
  import org.apache.skywalking.oap.server.core.cluster.ClusterRegister;
  import org.apache.skywalking.oap.server.library.module.ModuleProvider;
  import org.apache.skywalking.oap.server.library.module.ModuleStartException;
  import org.apache.skywalking.oap.server.library.module.ServiceNotProvidedException;
  import org.apache.skywalking.oap.server.library.util.Address;
  import org.apache.skywalking.oap.server.library.util.ConnectStringParseException;
  import org.apache.skywalking.oap.server.library.util.ConnectUtils;
  
  /**
   * Use consul to manage all service instances in SkyWalking cluster.
   */
  public class ClusterModuleConsulProvider extends ModuleProvider {
  
      private ClusterModuleConsulConfig config;
      private Consul client;
  
      @Override
      public String name() {
          return "consul";
      }
  
      @Override
      public Class module() {
          return ClusterModule.class;
      }
  
      @Override
      public ConfigCreator newConfigCreator() {
          return new ConfigCreator<ClusterModuleConsulConfig>() {
              @Override
              public Class type() {
                  return ClusterModuleConsulConfig.class;
              }
  
              @Override
              public void onInitialized(final ClusterModuleConsulConfig initialized) {
                  config = initialized;
              }
          };
      }
  
      @Override
      public void prepare() throws ServiceNotProvidedException, ModuleStartException {
          try {
              List<Address> addressList = ConnectUtils.parse(config.getHostPort());
  
              List<HostAndPort> hostAndPorts = new ArrayList<>();
              for (Address address : addressList) {
                  hostAndPorts.add(HostAndPort.fromParts(address.getHost(), address.getPort()));
              }
  
              Consul.Builder consulBuilder = Consul.builder()
                                                   //                    we should set this value or it will be blocked forever
                                                   .withConnectTimeoutMillis(3000);
  
              if (StringUtils.isNotEmpty(config.getAclToken())) {
                  consulBuilder.withAclToken(config.getAclToken());
              }
  
              if (hostAndPorts.size() > 1) {
                  client = consulBuilder.withMultipleHostAndPort(hostAndPorts, 5000).build();
              } else {
                  client = consulBuilder.withHostAndPort(hostAndPorts.get(0)).build();
              }
          } catch (ConnectStringParseException | ConsulException e) {
              throw new ModuleStartException(e.getMessage(), e);
          }
          ConsulCoordinator coordinator = new ConsulCoordinator(getManager(), config, client);
          this.registerServiceImplementation(ClusterRegister.class, coordinator);
          this.registerServiceImplementation(ClusterNodesQuery.class, coordinator);
          this.registerServiceImplementation(ClusterCoordinator.class, coordinator);
      }
  
      @Override
      public void start() {
      }
  
      @Override
      public void notifyAfterCompleted() {
      }
  
      @Override
      public String[] requiredModules() {
          return new String[] {CoreModule.NAME};
      }
  }
  