How can I integrate Prometheus with my Golang application?

How can I integrate Prometheus with my Golang application?

To integrate Prometheus with your Golang 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 such as 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 expose metrics by creating an HTTP handler using http.HandleFunc and calling prometheus.Handler(). Make sure to start an HTTP server to serve the metrics.

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 at the /metrics endpoint.