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.meter.analyzer.dsl.tagOpt;
  
  import com.google.common.base.Strings;
  import com.google.common.collect.ImmutableMap;
  import com.google.common.collect.Maps;
  import java.util.Arrays;
  import java.util.Map;
  import org.apache.skywalking.oap.meter.analyzer.dsl.Sample;
  import org.apache.skywalking.oap.meter.analyzer.k8s.K8sInfoRegistry;
  
  public enum K8sRetagType implements Retag {
      Pod2Service {
          @Override
          public Sample[] execute(final Sample[] ss,
                                  final String newLabelName,
                                  final String existingLabelName,
                                  final String namespaceLabelName) {
              return Arrays.stream(ss).map(sample -> {
                  String podName = sample.getLabels().get(existingLabelName);
                  String namespace = sample.getLabels().get(namespaceLabelName);
                  if (!Strings.isNullOrEmpty(podName) && !Strings.isNullOrEmpty(namespace)) {
                      String serviceName = K8sInfoRegistry.getInstance().findServiceName(namespace, podName);
                      if (Strings.isNullOrEmpty(serviceName)) {
                          serviceName = BLANK;
                      }
                      Map<String, String> labels = Maps.newHashMap(sample.getLabels());
                      labels.put(newLabelName, serviceName);
                      return sample.toBuilder().labels(ImmutableMap.copyOf(labels)).build();
                  }
                  return sample;
              }).toArray(Sample[]::new);
          }
      }
  }
  