node-exporter新增自定义模块

业务效果

源码修改

1.添加源码模块

go 1.16以后不再需要把源码包存储到gopath目录下，可以放到服务器的任何目录下即可

package collector

import (
    "github.com/go-kit/log"
    "github.com/prometheus/client_golang/prometheus"
    "os/exec"
    "strconv"
    "strings"
    "fmt"
)

const (
    errLogSubSystem = "errlog"
)

func init() {
    registerCollector(errLogSubSystem,defaultEnabled,NewErrLogCollector)
}


type errLogCollector struct {
    logger log.Logger
}

func NewErrLogCollector(logger log.Logger) (Collector,error) {
   return &errLogCollector{logger},nil
}


func errLogGrep() string {
    errLogCmd := `grep -i error /var/log/messages | awk '{a[$5]++}END{for(i in a) print i,a[i]}'`
    cmd := exec.Command("sh","-c",errLogCmd)
    output,_ := cmd.CombinedOutput()
    return string(output)
}

func (c *errLogCollector) Update( ch chan<- prometheus.Metric) error {
     var metricType prometheus.ValueType
         metricType = prometheus.GaugeValue

         output := errLogGrep()
         for _, line := range strings.Split(output,"\n") {
             l := strings.Split(line,":")
             if len(l) != 2 {
                 continue
             }

             name := strings.TrimSpace(l[0])
             value := strings.TrimSpace(l[1])

             v, _ := strconv.Atoi(value)
             name = strings.Replace(name,"-","_",-1)

             ch <- prometheus.MustNewConstMetric(
                 prometheus.NewDesc(
                     prometheus.BuildFQName(namespace,errLogSubSystem,name),
                     fmt.Sprintf("/var/log/message err log %s.", name),
                     nil,
                     nil,
                 ),
                 metricType, float64(v),
             )

         }
         return nil
}