Prometheus监控配置kubernetes_sd_config

官网对kubernetes_sd_config的详细说明文档

https://prometheus.io/docs/prometheus/latest/configuration/configuration/#kubernetes_sd_config

kubernetes_sd_config用于配置自动发现的。关于服务自动发现，还可以参考这篇实战：Prometheus kubernetes-cadvisor服务自动发现

Kubernetes SD configurations allow retrieving scrape targets from Kubernetes’ REST API and always staying synchronized with the cluster state.

role的类型有以下几种：node, service, pod, endpoints和ingress。

当role的值为endpoints时，官网说明：

The endpoints role discovers targets from listed endpoints of a service. For each endpoint address one target is discovered per port. If the endpoint is backed by a pod, all additional container ports of the pod, not bound to an endpoint port, are discovered as targets as well.

然后prometheus-additional.yaml的容是：

- job_name: 'kubernetes-service-endpoints'
  kubernetes_sd_configs:
  - role: endpoints
  relabel_configs:
  - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
    action: keep
    regex: true
  - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
    action: replace
    target_label: __scheme__
    regex: (https?)
  - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
    action: replace
    target_label: __metrics_path__
    regex: (.+)
  - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
    action: replace
    target_label: __address__
    regex: ([^:]+)(?::\d+)?;(\d+)
    replacement: $1:$2
  - action: labelmap
    regex: __meta_kubernetes_service_label_(.+)
  - source_labels: [__meta_kubernetes_namespace]
    action: replace
    target_label: kubernetes_namespace
  - source_labels: [__meta_kubernetes_service_name]
    action: replace
    target_label: kubernetes_name

我理解的逻辑是：

1. 首先查找ep,svc两个同时存在的
2. 然后查找svc的annotations标签__meta_kubernetes_service_annotation_prometheus_io_scrape的值为true的。
3. 最后看到ep里面有两个Addresses，所以显示两个Targets。