How can I integrate Prometheus with my Go application?

How can I integrate Prometheus with my Go application?

To integrate Prometheus with your Go application, you can use the Prometheus Go client library. First, install it using go get github.com/prometheus/client_golang/prometheus. Then, you can create metrics and expose them via an HTTP endpoint.

What kind of metrics can I collect?

You can collect various metrics like counters, gauges, histograms, and summaries. For example, you can track request counts, response times, and error rates.

How do I expose the metrics over HTTP?

You can use the http.Handle function to expose the metrics. Typically, you would set up an endpoint like /metrics where Prometheus can scrape the data.

Can you show me a code example?

Sure! Here's a simple example:

package main

import (
    "net/http"
    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
)

var (
    requestCount = prometheus.NewCounterVec(
        prometheus.CounterOpts{
            Name: "http_requests_total",
            Help: "Total number of HTTP requests",
        },
        []string{"method"},
    )
)

func init() {
    prometheus.MustRegister(requestCount)
}

func handler(w http.ResponseWriter, r *http.Request) {
    requestCount.WithLabelValues(r.Method).Inc()
    w.Write([]byte("Hello, World!"))
}

func main() {
    http.HandleFunc("/", handler)
    http.Handle("/metrics", promhttp.Handler())
    http.ListenAndServe(":8080", nil)
}

This code sets up a basic HTTP server and exposes metrics.