目前公司在用的Prometheus是安装在k8s集群中，安装方式类似如下如下链接：
https://blog.csdn.net/zhangshaohuas/article/details/107681209
安装于k8s集群中的Prometheus如果要监控k8s集群外的服务或者服务器，那么需要用到k8s的endpoint资源，将外部服务映射为集群的内部服务，然后进行访问通信。
Kubernetes-服务连接和暴露（endpoints）（二十） (juejin.cn)
创建好能连接外部资源的endponit 后，再创建service 和serviceMonitor资源 就能监控到一个外部服务，如下是范例yaml文件：

监控外部linux主机的serviceMonitor\service\endpoint的yaml

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: linux-metrics-sm
  namespace: monitoring
  labels:
    prometheus: k8s
spec:
  namespaceSelector:
    matchNames:
    - monitoring
  selector:
    matchLabels:
      k8s-app: linux-metrics
  endpoints:
  - port: metrics
    interval: 10s
 
---
 
apiVersion: v1
kind: Service
metadata:
  name: linux-metrics
  namespace: monitoring
  labels:
    k8s-app: linux-metrics
spec:
  type: ExternalName
  externalName: 192.168.0.20
  clusterIP: ""
  ports:
  - name: metrics
    port: 9100
    protocol: TCP
    targetPort: 9100
 
---
 
apiVersion: v1
kind: Endpoints
metadata:
  name: linux-metrics   #name与service的name一致
  namespace: monitoring
  labels:
    k8s-app: linux-metrics
subsets:
  - addresses:
    - ip: 192.168.0.20
    ports:
      - name: metrics
        port: 9100
        protocol: TCP