k8s之Prometheus-node-down解决

# prometheus-server配置如下
[root@k8s-master-1 prometheus-server]# cat prometheus-config.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-prometheus
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s 
      scrape_timeout: 10s
      evaluation_interval: 1m
    scrape_configs:
    - job_name: 'kubernetes-node'
      kubernetes_sd_configs:
      - role: node
    - job_name: 'prometheus-server'
      static_configs:
      - targets: ['localhost:9090']
      relabel_configs:
      - source_labels: [instance]  
        regex: '(.*)'
        replacement: 'prometheus-server:9090'
        target_label: instance
        action: replace

• 通过上述可以发现，当我们在node_exporter部署好了以后，默认会去http://IP:10250/metrics拉取数据，但是我们一般都是设置node_exporter与宿主机共享网络，所以应该是要去http://IP:9100/metrics拉取数据，故而要重新relabels一下标签

# prometheus配置
[root@k8s-master-1 prometheus-server]# cat prometheus-config.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-prometheus
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s 
      scrape_timeout: 10s
      evaluation_interval: 1m
    scrape_configs:
    - job_name: 'kubernetes-node'
      kubernetes_sd_configs:
      - role: node
      relabel_configs:
      - source_labels: [__address__]          # 将__address__=192.168.0.10:10250 -> 192.168.0.10:9100,node_exporter默认是9100，且我已事先与宿主机共享网络空间了
        regex: '(.*):10250'
        replacement: '${1}:9100'
        target_label: __address__
        action: replace
      - action: labelmap                 
        regex: __meta__kubernetes_node_label_(.*)  # 保留__meta__kubernetes_node_label_标签后面的值作为新标签
    - job_name: 'prometheus-server'
      static_configs:
      - targets: ['localhost:9090']
      relabel_configs:
      - source_labels: [instance]             # 将instance=localhost:9090 -> instance=prometheus-server:9090
        regex: '(.*)'
        replacement: 'prometheus-server:9090'
        target_label: instance
        action: replace

• 可以发现将__address__修改成IP：9100后，即可正常获取metrics