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.configuration.consul;
  
  import com.google.common.base.Strings;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.oap.server.configuration.api.AbstractConfigurationProvider;
  import org.apache.skywalking.oap.server.configuration.api.ConfigWatcherRegister;
  import org.apache.skywalking.oap.server.library.module.ModuleStartException;
  
  /**
   * Get configuration from Consul.
   */
  @Slf4j
  public class ConsulConfigurationProvider extends AbstractConfigurationProvider {
      private ConsulConfigurationCenterSettings settings;
  
      @Override
      public String name() {
          return "consul";
      }
  
      @Override
      public ConfigCreator newConfigCreator() {
          return new ConfigCreator<ConsulConfigurationCenterSettings>() {
              @Override
              public Class type() {
                  return ConsulConfigurationCenterSettings.class;
              }
  
              @Override
              public void onInitialized(final ConsulConfigurationCenterSettings initialized) {
                  settings = initialized;
              }
          };
      }
  
      @Override
      protected ConfigWatcherRegister initConfigReader() throws ModuleStartException {
          log.info("consul settings: {}", settings);
  
          if (Strings.isNullOrEmpty(settings.getHostAndPorts())) {
              throw new ModuleStartException("Consul hostAndPorts cannot be null or empty");
          }
  
          return new ConsulConfigurationWatcherRegister(settings);
      }
  }
  