prometheus监控java应用的jvm指标

在k8s环境中我们有很多的java应用，需要监控其性能我们可以通过集成jmx的客户端，然后通过promethues的自动发现来实现监控数据的获取。
promethues的部署he相关配置可参考：promethues部署

准备jmx的客户端和配置文件

jmx_prometheus_javaagent-0.17.2.jar(版本自定义，可以直接打包到镜像里)

使用configmap挂载jmx-config.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-jmx-config
  namespace: monitor
data:
  prometheus-jmx-config.yaml: |
    lowercaseOutputLabelNames: true
    lowercaseOutputName: true
    whitelistObjectNames: ["java.lang:type=OperatingSystem"]
    blacklistObjectNames: []
    rules:
      - pattern: 'java.lang<type=OperatingSystem><>(committed_virtual_memory|free_physical_memory|free_swap_space|total_physical_memory|total_swap_space)_size:'
        name: os_$1_bytes
        type: GAUGE
        attrNameSnakeCase: true
      - pattern: 'java.lang<type=OperatingSystem><>((?!process_cpu_time)\w+):'
        name: os_$1
        type: GAUGE
        attrNameSnakeCase: true

部署应用（tomcat为例）

apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat
  namespace: monitor
spec:
  replicas: 2
  selector:
    matchLabels:
      app: tomcat
  template:
    metadata:
      labels:
        app: tomcat
    spec:
      containers:
      - name: tomcat
        image: tomcat:jdk8-openjdk-slim
        env:
        - name: JAVA_OPTS
          value: "-javaagent:/jmx_prometheus_javaagent-0.17.2.jar=8088:/jmx/jmx-config.yaml"  **# (添加的启动命令参数)**
        resources:
          requests:
            cpu: 300m
            memory: 512Mi
          limits:
            cpu: 500m
            memory: 1024Mi
        volumeMounts:
        - mountPath: "/jmx_prometheus_javaagent-0.17.2.jar"    **#(将客户端挂载到容器)**
          name: jmx-prometheus-javaagent
        - mountPath: "/jmx"
          name: prometheus-jmx-config       **#(通过configmap挂载配置文件)**
      volumes:
      - name: jmx-prometheus-javaagent
        hostPath:
          path: /data/k8s_yaml/jvm/jmx_prometheus_javaagent-0.17.2.jar  **# (使用的是挂在本地路径)**
      - configMap: 
          name: prometheus-jmx-config
        name: prometheus-jmx-config
      nodeSelector:
        kubernetes.io/hostname: 10.1.40.121

服务的service

apiVersion: v1
kind: Service
metadata:
  name: tomcat
  namespace: monitor
  labels:
    app: tomcat
  annotations:
    prometheus.io/port: "8088"     **#(jmx监听的端口)**
    prometheus.io/jvm: "true"
spec:
  type: NodePort
  selector:
    app: tomcat
  ports:
  - name: http
    port: 8080
    protocol: TCP
  - name: jmx-metrics
    port: 8088
    protocol: TCP