kube-prometheus-stack 监控CoreDNS

在部署 Docker运行CoreDNS 之后，需要修订 kube-prometheus-stack 来监控独立部署的 CoreDNS :

• 采用独立抓取(scrap)主机节点端口 553 Metrics

• 关闭默认通过k8s的 prometheus_sd_config 方式获取coredns targets(原因是废弃了k8s集群内置coredns

默认CoreDNS scrap

• 默认 values.yaml 中配置scrap coreDns的配置如下:

默认coreDns的scrap配置

## Component scraping coreDns. Use either this or kubeDns
##
coreDns:
  enabled: true
  service:
    port: 9153
    targetPort: 9153
    # selector:
    #   k8s-app: kube-dns
  serviceMonitor:
    ## Scrape interval. If not set, the Prometheus default scrape interval is used.
    ##
    interval: ""

    ## SampleLimit defines per-scrape limit on number of scraped samples that will be accepted.
    ##
    sampleLimit: 0

    ## TargetLimit defines a limit on the number of scraped targets that will be accepted.
    ##
    targetLimit: 0

    ## Per-scrape limit on number of labels that will be accepted for a sample. Only valid in Prometheus versions 2.27.0 and newer.
    ##
    labelLimit: 0

    ## Per-scrape limit on length of labels name that will be accepted for a sample. Only valid in Prometheus versions 2.27.0 and newer.
    ##
    labelNameLengthLimit: 0

    ## Per-scrape limit on length of labels value that will be accepted for a sample. Only valid in Prometheus versions 2.27.0 and newer.
    ##
    labelValueLengthLimit: 0

    ## proxyUrl: URL of a proxy that should be used for scraping.
    ##
    proxyUrl: ""

    ## MetricRelabelConfigs to apply to samples after scraping, but before ingestion.
    ## ref: https://github.com/prometheus-operator/prometheus-operator/blob/main/Documentation/api.md#relabelconfig
    ##
    metricRelabelings: []
    # - action: keep
    #   regex: 'kube_(daemonset|deployment|pod|namespace|node|statefulset).+'
    #   sourceLabels: [__name__]

    ## RelabelConfigs to apply to samples before scraping
    ## ref: https://github.com/prometheus-operator/prometheus-operator/blob/main/Documentation/api.md#relabelconfig
    ##
    relabelings: []
    # - sourceLabels: [__meta_kubernetes_pod_node_name]
    #   separator: ;
    #   regex: ^(.*)$
    #   targetLabel: nodename
    #   replacement: $1
    #   action: replace

    ## Additional labels
    ##
    additionalLabels: {}
    #  foo: bar

修订node抓取配置