如何使用 gin 作为服务器来编写 prometheus 导出器指标

Posted 2023-02-16

【中文标题】如何使用 gin 作为服务器来编写 prometheus 导出器指标

【英文标题】：How to use gin as a server to write prometheus exporter metrics

【发布时间】：2021-04-12 22:58:39

【问题描述】：

这是官方prometheus golang-client示例：

package main

import (
    "log"
    "net/http"

    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
)

var cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts
        Name: "cpu_temperature_celsius",
        Help: "Current temperature of the CPU.",
    )


func init() 
    // Metrics have to be registered to be exposed:
    prometheus.MustRegister(cpuTemp)


func main() 
    cpuTemp.Set(65.3)

    // The Handler function provides a default handler to expose metrics
    // via an HTTP server. "/metrics" is the usual endpoint for that.
    http.Handle("/metrics", promhttp.Handler())
    log.Fatal(http.ListenAndServe(":8080", nil))

在此代码中，http 服务器使用promhttp 库。

在使用gin 框架时如何修改指标处理程序？我在documentation 中没有找到答案。

【问题讨论】：

gqlgen.com/recipes/gin

【参考方案1】：

我们只使用promhttp 处理程序。

package main

import (
    "github.com/gin-gonic/gin"
    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
)

var cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts
    Name: "cpu_temperature_celsius",
    Help: "Current temperature of the CPU.",
)

func init() 
    prometheus.MustRegister(cpuTemp)


func prometheusHandler() gin.HandlerFunc 
    h := promhttp.Handler()

    return func(c *gin.Context) 
        h.ServeHTTP(c.Writer, c.Request)
    


func main() 
    cpuTemp.Set(65.3)

    r := gin.New()

    r.GET("/", func(c *gin.Context) 
        c.JSON(200, "Hello world!")
    )

    r.GET("/metrics", prometheusHandler())

    r.Run()

或者我们总是可以切换到 Prometheus 中间件 - https://github.com/zsais/go-gin-prometheus

【参考方案2】：

我正在使用 prometheus 和其他库 https://github.com/Depado/ginprom:

package main

import (
    "github.com/Depado/ginprom"
    "github.com/gin-gonic/gin"
)

func main() 
    r := gin.Default()
    p := ginprom.New(
        ginprom.Engine(r),
        ginprom.Subsystem("gin"),
        ginprom.Path("/metrics"),
    )
    r.Use(p.Instrument())

    r.GET("/hello/:id", func(c *gin.Context) )
    r.GET("/world/:id", func(c *gin.Context) )
    r.Run("127.0.0.1:8080")