How to push metrics to prometheus using client_golang? - go

Question

I have not yet able to find some good examples in using Gauge, Counter and Histogram in prometheus. Any help on this will do. I tried using the the documentation but I was not able to successfully create a working app.

Answer 1

You could find examples form the prometheus/client_golang. To get you started, you can just get the packages:
$ go get github.com/prometheus/client_golang/prometheus
$ go get github.com/prometheus/client_golang/prometheus/push
The you can just run the following example by setting your correct pushgateway address, which is http://localhost:9091/ in this example:
package main
import (
"fmt"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/push"
)
func ExamplePusher_Push() {
completionTime := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "db_backup_last_completion_timestamp_seconds",
Help: "The timestamp of the last successful completion of a DB backup.",
})
completionTime.SetToCurrentTime()
if err := push.New("http://localhost:9091/", "db_backup").
Collector(completionTime).
Grouping("db", "customers").
Push(); err != nil {
fmt.Println("Could not push completion time to Pushgateway:", err)
}
}
func main() {
ExamplePusher_Push()
}
Run your script:
$ go run pushExample.go
After running your code, you should see the metrics at your gateway (http://localhost:9091/). The interface looks like the following:

Answer 2

I have found this
`
package main
import (
"net/http"
"github.com/prometheus/client_golang/prometheus"
)
var (
cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{
Name: "cpu_temperature_celsius",
Help: "Current temperature of the CPU.",
})
hdFailures = prometheus.NewCounter(prometheus.CounterOpts{
Name: "hd_errors_total",
Help: "Number of hard-disk errors.",
})
)
func init() {
prometheus.MustRegister(cpuTemp)
prometheus.MustRegister(hdFailures)
}
func main() {
cpuTemp.Set(65.3)
hdFailures.Inc()
http.Handle("/metrics", prometheus.Handler())
http.ListenAndServe(":8080", nil)
}
`
This might be useful to some.

Answer 3

Prometheus is a pull-based system, if you want push-based monitoring, you need to use a gateway of some sort. A minimal example (without actually doing anything useful like starting an HTTP listener, or actually doing anything to a metric) follows:
import (
"github.com/prometheus/client_golang/prometheus"
"net/http"
)
var responseMetric = prometheus.NewHistogram(
prometheus.HistogramOpts{
Name: "request_duration_milliseconds",
Help: "Request latency distribution",
Buckets: prometheus.ExponentialBuckets(10.0, 1.13, 40),
})
func main() {
prometheus.MustRegister(responseMetric)
http.Handle("/metrics", prometheus.Handler())
// Any other setup, then an http.ListenAndServe here
}
You then need to configure Prometheus to scrape the /metrics page your binary provides.