Spring Boot configuration to wire Spinnaker K8S v2 Provider annotations to Micrometer for use in Kayenta

deployment.yml

---
apiVersion: apps/v1
kind: Deployment
...
spec:
  template:
    spec:
      serviceAccountName: replicaset-annotations-service-account
...

service-account.yml

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: replicaset-annotations-service-account
  namespace: default
  labels:
    name: replicaset-annotations-service-account
    app: appname
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: replicaset-annotations-role
  namespace: default
  labels:
    name: replicaset-annotations-role
    app: appname
rules:
- apiGroups: ["apps"]
  resources: ["replicasets"]
  verbs: ["get"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: replicaset-annotations-role-binding
  namespace: default
  labels:
    name: replicaset-annotations-role-binding
    app: appname
subjects:
- kind: ServiceAccount
  name: replicaset-annotations-service-account
roleRef:
  kind: Role
  name: replicaset-annotations-role-binding
  apiGroup: rbac.authorization.k8s.io

SpinnakerMetricsConfiguration.java

@Configuration
public class PaneraMetricsAutoConfiguration {
  private final Logger logger = LoggerFactory.getLogger(PaneraMetricsAutoConfiguration.class);
​
  @Value("${spring.application.name:unknown}")
  private String appName;
​
  @Value("${HOSTNAME:unknown}")
  private String host;
​
  @Bean
  public MeterFilter httpDistributionStatistics() {
    return new MeterFilter() {
      @Override
      public DistributionStatisticConfig configure(Meter.Id id,
          DistributionStatisticConfig config) {
        if (id.getName().equals("http.server.requests")) {
          return DistributionStatisticConfig.builder().percentilesHistogram(true).build()
              .merge(config);
        }
        return config;
      }
    };
  }
​
  @Bean
  @ConditionalOnBean(KubernetesClient.class)
  public MeterFilter kubernetesMeterFilter(KubernetesClient k8sClient) {
    return new MeterFilter() {
      @Override
      public Meter.Id map(Meter.Id id) {
        try {
          // Spinnaker adds annotations to the replicaSet. So we need to determine the replicaSet by looking at the pod's owner
          // information.
          Map<String, String> annotations = k8sClient
              .pods()
              .withName(host)
              .get()
              .getMetadata()
              .getOwnerReferences()
              .stream()
              .findFirst()
              .map(ref -> k8sClient.apps().replicaSets().withName(ref.getName()).get())
              .map(replicaSet -> replicaSet.getMetadata().getAnnotations()).orElse(emptyMap());
​
          return id.withTags(Tags.of(
              "revision", annotations.getOrDefault("deployment.kubernetes.io/revision", "unknown"),
              "application", annotations.getOrDefault("moniker.spinnaker.io/application", appName),
              "cluster", annotations.getOrDefault("moniker.spinnaker.io/cluster", "unknown"),
              "location", annotations.getOrDefault("artifact.spinnaker.io/location", "unknown")));
        } catch (KubernetesClientException e) {
          logger.warn("Unable to apply kubernetes telemetry tags", e);
          
          // we tried... at least add application and host tags
          return id.withTag(Tag.of("application", appName, "host", host));
        }
      }
    };
  }
​
  @Bean
  @ConditionalOnMissingBean(KubernetesClient.class)
  public MeterFilter meterFilter() {
    return MeterFilter.commonTags(Tags.of("application", appName, "host", host));
  }
​
  @ConditionalOnMissingBean
  @Bean(destroyMethod = "pushAndClose")
  PrometheusRSocketClient prometheusRSocketClient(PrometheusMeterRegistry meterRegistry) {
    return new PrometheusRSocketClient(meterRegistry,
        WebsocketClientTransport.create("104.198.168.96", 8081),
        c -> c.retryBackoff(Long.MAX_VALUE, Duration.ofSeconds(3), Duration.ofMinutes(2)));
  }
}

Add dependency implementation 'io.fabric8:kubernetes-client'.

K8S does not allow access to replicaset annotations from the default service account (unless its privileges are elevated beyond the default). You must create a role binding granting replicasets/get and associate it with a service account that is attached to the deployment/statefulset.