Posting to pushgateway using prometheus go client

[Anurupa Dhamala]

I am trying to push my metrics to a pushgateway in a go routine. But I keep getting 
```collected metric "packet_received" { label:{name:"client_name" value:"machine1"} counter:{value:1 created_timestamp:{seconds:1728120095 nanos:654777418}}} was collected before with the same name and label values``` this error

I dont understand how to push the metrics. Here is how I have implemented my code 

package main

import (

    "context"

    "fmt"

    "os"

    "os/signal"

    "syscall"

    "time"

    "example.com/logger"

    "github.com/prometheus/client_golang/prometheus"

    "github.com/prometheus/client_golang/prometheus/push"

)

var prometheusMetrics *logger.PrometheusMetrics

func main() {

    prom := "http://172.17.0.1:9091"

    go initPrometheus(prom)

    quit := make(chan os.Signal, 1)

    signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)

    <-quit

}

func initPrometheus(url string) {

    ctx, cancel := context.WithCancel(context.Background())

    defer cancel()

    i := 0

    pusher := push.New(url, "verulink_test").Grouping("instance", "test")

    prometheusMetrics = logger.NewPrometheusMetrics()

    ticker := time.NewTicker(5 * time.Second)

    defer ticker.Stop()

    for {

        select {

        case <-ctx.Done():

            fmt.Println("Stopping metric push...")

            return

        case <-ticker.C:

            prometheusMetrics.AddInPackets("machine1", i)

            gatherer := prometheus.Gatherers{

                prometheusMetrics.Registry,

            }

            fmt.Println("Attempting to push metrics...")

            if err := pusher.Gatherer(gatherer).Push(); err != nil {

                fmt.Printf("Error pushing metrics to Pushgateway: %s\n", err)

            } else {

                fmt.Println("Metrics pushed successfully.")

            }

            i++

        }

    }

}

[Bjoern Rabenstein]

On 05.10.24 02:24, Anurupa Dhamala wrote:
> I am trying to push my metrics to a pushgateway in a go routine. But I keep
> getting
> ```collected metric "packet_received" { label:{name:"client_name"
> value:"machine1"} counter:{value:1 created_timestamp:{seconds:1728120095
> nanos:654777418}}} was collected before with the same name and label
> values``` this error

Where exactly is this error message coming from?

I would guess it is created before the push is even attempted. It
probably happens during metrics collection (which happens before
metrics are pushed). Such a message is created if there are two
metrics with the same name and label set. Presumably, there is a bug
in the `logger` package.


--
Björn Rabenstein
[PGP-ID] 0x851C3DA17D748D03
[email] bjo...@rabenste.in

[Anurupa Dhamala]

The error log was " was collected before with the same name and label values  " but I did manage to solve this. 
I had been creating a new gatherer inside the for loop, and every new gatherer is appended. So while pushing there were multiple gatherer with same metrics name and label set. I solved it by pushing the gatherer to pusher object outside of the for loop. 

func initPrometheus(url string) {

    ctx, cancel := context.WithCancel(context.Background())

    defer cancel()

    i := 0

    pusher := push.New(url, "test").Grouping("instance", "test")

    prometheusMetrics = logger.NewPrometheusMetrics()

    pusher.Gatherer(prometheusMetrics.Registry)

    ticker := time.NewTicker(5 * time.Second)

    defer ticker.Stop()

    for {

        select {

        case <-ctx.Done():

            fmt.Println("Stopping metric push...")

            return

        case <-ticker.C:

            prometheusMetrics.AddInPackets("machine1", i)

            fmt.Println("Attempting to push metrics...")

            if err := pusher.Push(); err != nil {

                fmt.Printf("Error pushing metrics to Pushgateway: %s\n", err)

            } else {

                fmt.Println("Metrics pushed successfully.")

            }

            i++

        }

    }

}