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.cassandra.locator;
  
  import java.io.IOException;
  
  import com.google.common.collect.ImmutableMap;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import org.apache.cassandra.exceptions.ConfigurationException;
  import org.apache.cassandra.locator.AbstractCloudMetadataServiceConnector.DefaultCloudMetadataServiceConnector;
  import org.apache.cassandra.tcm.membership.Location;
  import org.apache.cassandra.utils.JsonUtils;
  
  import static java.lang.String.format;
  import static org.apache.cassandra.locator.AbstractCloudMetadataServiceConnector.METADATA_URL_PROPERTY;
  
  public class AzureCloudLocationProvider extends CloudMetadataLocationProvider
  {
      static final String DEFAULT_METADATA_SERVICE_URL = "http://169.254.169.254";
      static final String METADATA_QUERY_TEMPLATE = "/metadata/instance/compute?api-version=%s&format=json";
      static final String METADATA_HEADER = "Metadata";
      static final String API_VERSION_PROPERTY_KEY = "azure_api_version";
      static final String DEFAULT_API_VERSION = "2021-12-13";
  
      /**
       * Used via reflection by DatabaseDescriptor::createInitialLocationProvider
       */
      public AzureCloudLocationProvider() throws IOException
      {
          this(new SnitchProperties());
      }
  
      public AzureCloudLocationProvider(SnitchProperties properties) throws IOException
      {
          this(new DefaultCloudMetadataServiceConnector(properties.putIfAbsent(METADATA_URL_PROPERTY,
                                                                               DEFAULT_METADATA_SERVICE_URL)));
      }
  
      public AzureCloudLocationProvider(AbstractCloudMetadataServiceConnector connector) throws IOException
      {
          super(connector, AzureCloudLocationProvider::resolveLocation);
      }
  
      static Location resolveLocation(AbstractCloudMetadataServiceConnector connector) throws IOException
      {
          String apiVersion = connector.getProperties().get(API_VERSION_PROPERTY_KEY, DEFAULT_API_VERSION);
          String response = connector.apiCall(format(METADATA_QUERY_TEMPLATE, apiVersion),
                                              ImmutableMap.of(METADATA_HEADER, "true"));
          JsonNode jsonNode = JsonUtils.JSON_OBJECT_MAPPER.readTree(response);
  
          JsonNode location = jsonNode.get("location");
          JsonNode zone = jsonNode.get("zone");
          JsonNode platformFaultDomain = jsonNode.get("platformFaultDomain");
  
          String datacenter;
          String rack;
  
          if (location == null || location.isNull() || location.asText().isEmpty())
              throw new ConfigurationException("Unable to retrieve initial location from cloud metadata service. " +
                                               "This is required for registration, please check configuration");
          else
              datacenter = location.asText();
  
          if (zone == null || zone.isNull() || zone.asText().isEmpty())
          {
              if (platformFaultDomain == null || platformFaultDomain.isNull() || platformFaultDomain.asText().isEmpty())
              {
                  throw new ConfigurationException("Unable to retrieve initial zone or platform fault domain from cloud metadata service. " +
                                                   "This is required for registration, please check configuration");
              }
              else
              {
                  rack = platformFaultDomain.asText();
              }
          }
          else
          {
              rack = zone.asText();
          }
  
          return new Location(datacenter + connector.getProperties().getDcSuffix(), "rack-" + rack);
      }
  }
  