更新 opentelemetry prometheus 导出器中的标签

如何解决更新 opentelemetry prometheus 导出器中的标签

在运行 opentelemetry prometheus 导出器的指标示例时得到了预期

    prometheus metrics:
    # HELP ex_com_one A ValueObserver set to 1.0
    # TYPE ex_com_one histogram
    ex_com_one_bucket{ex_com_lemons="13",le="+Inf"} 1
    ex_com_one_sum{ex_com_lemons="13"} 1
    ex_com_one_count{ex_com_lemons="13"} 1
    # HELP ex_com_three 
    # TYPE ex_com_three counter
    ex_com_three{ex_com_lemons="13"} 22
    ex_com_three{A="1",B="2",C="3",ex_com_lemons="10"} 12
    # HELP ex_com_two 
    # TYPE ex_com_two histogram
    ex_com_two_bucket{ex_com_lemons="13",le="+Inf"} 1
    ex_com_two_sum{ex_com_lemons="13"} 2
    ex_com_two_count{ex_com_lemons="13"} 1
    ex_com_two_bucket{A="1",ex_com_lemons="10",le="+Inf"} 1
    ex_com_two_sum{A="1",ex_com_lemons="10"} 2
    ex_com_two_count{A="1",ex_com_lemons="10"} 1

在 []label.keyvalue 中添加了一些虚拟值，所以我得到了指标，但我打算得到方法 指标中的名称和主机名。所以我添加了一个匿名函数并在变量中分配了返回值。 正如您在下面的源代码中看到的那样。

// copyright The OpenTelemetry Authors
//
// Licensed under the Apache License,Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,software
// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package metrics

import (
    "context"
    "fmt"
    "log"
    "net/http"
    "sync"
    "time"

    "go.opentelemetry.io/otel"
    "go.opentelemetry.io/otel/exporters/metric/prometheus"
    "go.opentelemetry.io/otel/label"
    "go.opentelemetry.io/otel/metric"
)

type MyResponseWriter struct {
    rw http.ResponseWriter
    r *http.Request
}
var (
    lemonsKey = label.Key("ex.com/lemons")
    //commonLabels = [...]label.keyvalue{}
    
)

func initMeter() {
    exporter,err := prometheus.InstallNewPipeline(prometheus.Config{})
    
    if err != nil {
        log.Panicf("Failed to initialize prometheus exporter %v",err)
    }
    http.HandleFunc("/",exporter.ServeHTTP)
    go func() {
        http.ListenAndServe(":2222",nil)
    }()

    fmt.Println("Prometheus server running on :2222")
}

func init() {
    initMeter()
    
    meter := otel.Meter("prometheus")

    //meter.
    observerLock := new(sync.RWMutex)
    observerValuetoReport := new(float64)
    observerLabelsToReport := new([]label.keyvalue)
    cb := func(_ context.Context,result metric.Float64ObserverResult) {
        (*observerLock).RLock()
        value := *observerValuetoReport
        labels := *observerLabelsToReport
        (*observerLock).RUnlock()
        result.Observe(value,labels...)
    }
    _ = metric.Must(meter).NewFloat64ValueObserver("mem_usage_per_app",cb,metric.WithDescription("cpu"),)
    _ = metric.Must(meter).NewFloat64ValueObserver("cpu_usage_per_app",metric.WithDescription("Memory"),)

    valuerecorder := metric.Must(meter).NewFloat64ValueRecorder("HTTP_Request_duration_seconds_bucket")
    counter := metric.Must(meter).NewFloat64Counter("HTTP_Request_duration_seconds_count")
    


    commonLabels:=func(rw http.ResponseWriter,r *http.Request)[]label.keyvalue{
        return []label.keyvalue{lemonsKey.Int(10),label.String("Method","a"),label.String("B","2"),label.String("C","3")}
    }
    
    notSoCommonLabels := []label.keyvalue{lemonsKey.Int(13)}

    ctx := context.Background()

    (*observerLock).Lock()
    *observerValuetoReport = 1.0
    *observerLabelsToReport = commonLabels
    (*observerLock).Unlock()
    
    meter.RecordBatch(
        ctx,commonLabels,valuerecorder.Measurement(2.0),counter.Measurement(12.0),)

    time.Sleep(5 * time.Second)

    (*observerLock).Lock()
    *observerValuetoReport = 1.0
    *observerLabelsToReport = notSoCommonLabels
    (*observerLock).Unlock()
    meter.RecordBatch(
        ctx,notSoCommonLabels,counter.Measurement(22.0),)

    fmt.Println("Example finished updating,please visit :2222")

    
}

但出现错误

Cannot use 'commonLabels' (type func(rw http.ResponseWriter,r *http.Request) []label.keyvalue) as type []label.keyvalue`

谁能帮我解决这个问题。

解决方法

根据你的描述，我认为是语法问题。

试试这个：

commonLabels := []label.KeyValue{
    lemonsKey.Int(10),label.String("Method",r.Method),label.String("Host",r.URL.Host),label.String("C","test"),}

或者如果您需要请求

commonLabels := func(rw http.ResponseWriter,r *http.Request)[]label.KeyValue{
        return []label.KeyValue{
        lemonsKey.Int(10),}
}(rw,r)

这将定义并调用一个返回 []label.KeyValue

的函子