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.receiver.envoy.metrics.adapters;
  
  import com.google.protobuf.Struct;
  import com.google.protobuf.Value;
  import io.prometheus.client.Metrics;
  import java.util.Map;
  import lombok.RequiredArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.skywalking.oap.server.library.util.StringUtil;
  import org.apache.skywalking.oap.server.receiver.envoy.EnvoyMetricReceiverConfig;
  import org.apache.skywalking.oap.server.receiver.envoy.als.ServiceMetaInfo;
  
  @Slf4j
  @RequiredArgsConstructor
  public class ClusterManagerMetricsAdapter {
      private static final String DEFAULT_VALUE = "-";
      private final EnvoyMetricReceiverConfig config;
  
      public String adaptMetricsName(final Metrics.MetricFamily metricFamily) {
  
          return "envoy_cluster_metrics";
      }
  
      public Map<String, String> adaptLabels(final Metrics.MetricFamily metricFamily, final Map<String, String> labels) {
          String metricsName = metricFamily.getName();
          labels.putIfAbsent("metrics_name", metricsName);
  
          String clusterName = null;
  
          try {
              clusterName = buildUpstreamServiceMetaInfo(metricFamily).getServiceName();
          } catch (Exception e) {
              log.error("Failed to build upstream serviceMetaInfo from metrics name. ", e);
          }
  
          if (StringUtil.isNotEmpty(clusterName)) {
              labels.putIfAbsent("cluster_name", clusterName);
          }
  
          return labels;
      }
  
      protected ServiceMetaInfo buildUpstreamServiceMetaInfo(final Metrics.MetricFamily metricFamily) throws Exception {
          String metricsName = metricFamily.getName();
          String serviceName = DEFAULT_VALUE;
          String ns = DEFAULT_VALUE;
          String version = DEFAULT_VALUE;
  
          String[] splitArrGeneral = StringUtils.split(metricsName, ".");
          if (metricsName.startsWith("cluster.outbound")) {
              String[] splitArrBound = metricsName.split("\\|");
              if (splitArrBound.length > 3) {
                  String[] splitArrClusterName = StringUtils.split(splitArrBound[3], ".");
                  version = splitArrBound[2];
                  if (splitArrClusterName.length > 1) {
                      if (StringUtil.isBlank(version)) {
                          version = "*";
                      }
                      serviceName = splitArrClusterName[0];
                      ns = splitArrClusterName[1];
                  }
              }
          } else if (metricsName.startsWith("cluster.inbound")) {
              String[] splitArrBound = metricsName.split("\\|");
              if (splitArrBound.length > 1) {
                  String[] splitArrClusterName = StringUtils.split(splitArrBound[0], ".");
                  if (splitArrClusterName.length > 1) {
                      serviceName = splitArrClusterName[1] + ":" + splitArrBound[1];
                  }
              }
          } else if (splitArrGeneral.length == 3) {
              serviceName = splitArrGeneral[1];
          }
  
          Value nsValue = Value.newBuilder().setStringValue(ns).build();
          Value nameValue = Value.newBuilder().setStringValue(serviceName).build();
          Value versionValue = Value.newBuilder().setStringValue(version).build();
          Struct labelStruct = Struct.newBuilder()
                                     .putFields("service.istio.io/canonical-name", nameValue)
                                     .putFields("app.kubernetes.io/name", nameValue)
                                     .putFields("app", nameValue)
                                     .putFields("service.istio.io/canonical-revision", versionValue)
                                     .putFields("version", versionValue).build();
          Value label = Value.newBuilder().setStructValue(labelStruct).build();
          Struct struct = Struct.newBuilder().putFields("NAMESPACE", nsValue).putFields("LABELS", label).build();
          return config.serviceMetaInfoFactory().fromStruct(struct);
      }
  }
  