exporter开发(下篇)

exporter开发(下篇)

准备工作已经在上篇讲过了，这里我们就直接开始撸代码

代码

目录结构：
.
├── collector
│   └── pid.go
└── main.go

main.go

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
package main

import (
	"custom_exporters/demo_04/collector"
	"fmt"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"net/http"
)

func main() {
	prometheus.MustRegister(collector.NewPidCollector())
	http.Handle("/metrics", promhttp.Handler())
	if err := http.ListenAndServe(":8080", nil); err != nil {
		fmt.Printf("Error occur when start server %v", err)
	}
}

pid.go 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
package collector

import (
  "github.com/prometheus/client_golang/prometheus"
  "github.com/shirou/gopsutil/host"
  "os"
  "sync"
)

type PidCollector struct {
  pidDesc    *prometheus.Desc   //当前collector的pid
  mutex          sync.Mutex
}

func NewPidCollector()PidCollector  {
  return PidCollector{pidDesc:  prometheus.NewDesc(
    "cur_collector_pid",
    "当前collector的pid",
    []string{"HOST_NAME"},
    nil)}

}
// Describe implements the prometheus.Collector interface.
func (p PidCollector) Describe(ch chan<- *prometheus.Desc) {
  ch <- p.pidDesc
}

// Collect implements the prometheus.Collector interface.This method may be called concurrently and must therefore be
// implemented in a concurrency safe way
func (p PidCollector) Collect(ch chan<- prometheus.Metric) {
  p.mutex.Lock()
  defer p.mutex.Unlock()
  host,_:= host.Info()
  ch <- prometheus.MustNewConstMetric(
    p.pidDesc,
    prometheus.GaugeValue,
    float64(os.Getpid()),
    host.Hostname,
  )
}

prometheus配置

1
2
3
4
5
6
7
8
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  # metrics_path defaults to '/metrics'
  # scheme defaults to 'http'.
  - job_name: 'pid collector'
    static_configs:
    - targets:
      - localhost:8080

效果

结尾

这只是一个简单的collector实践，如果有多个指标需要采集，我们就可以在 XXXCollector结构体里面定义多个Desc，具体指标值的获取，需要根据具体场景来实现。