为什么我的 Prometheus Operator ServiceMonitor 需要一个“release”标签才能正确 运行？

Question

当我部署这个时：

kind: ServiceMonitor
apiVersion: monitoring.coreos.com/v1
metadata:
  labels:
    app: complaints-monitor
    release: prometheus # <---------
  name: complaints-monitor-svc-monitor
  namespace: default
spec:
  endpoints:
    - path: /metrics
      port: web
  namespaceSelector:
    matchNames:
      - default
  selector:
    matchLabels:
      app: complaints-monitor

我的服务显示在 prometheus 目标下并正确运行。

如果我改为应用以下内容，目标就会消失：

kind: ServiceMonitor
apiVersion: monitoring.coreos.com/v1
metadata:
  labels:
    app: complaints-monitor
  name: complaints-monitor-svc-monitor
  namespace: default
spec:
  endpoints:
    - path: /metrics
      port: web
  namespaceSelector:
    matchNames:
      - default
  selector:
    matchLabels:
      app: complaints-monitor

Answer 1

查了kube-prometheus-stack的values.yaml才发现这个问题

• vaules.yaml

    ## If true, a nil or {} value for prometheus.prometheusSpec.serviceMonitorSelector will cause the
    ## prometheus resource to be created with selectors based on values in the helm deployment,
    ## which will also match the servicemonitors created
    ##
    serviceMonitorSelectorNilUsesHelmValues: true


    ## ServiceMonitors to be selected for target discovery.
    ## If {}, select all ServiceMonitors
    ##
    serviceMonitorSelector: {}
    ## Example which selects ServiceMonitors with label "prometheus" set to "somelabel"
    # serviceMonitorSelector:
    #   matchLabels:
    #     prometheus: somelabel

当您使用 helm 安装 kube-prometheus-stack 时，它会将标签 release: <prometheus-installed-namespace> 添加到 Kubernetes 资源。

如果设置 serviceMonitorSelectorNilUsesHelmValues 是 true 一个 select 或者将被添加到 prometheus.prometheusSpec.serviceMonitorSelector，在你的情况下是 release: prometheus.

您应该能够看到 select 或 prometheus 到 select serviceMonitor 使用命令

kubectl -n <prometheus-installed-namespace> get prometheus -o yaml

并搜索 serviceMonitorSelector.

您有两种选择可以在不添加 release 标签的情况下使其正常工作

1. 设置serviceMonitorSelectorNilUsesHelmValues为false，那么prometheus会select所有serviceMonitor

2. 或者，将 serviceMonitorSelector 设置为您喜欢的任何标签。