ctrl/prometheus.go

package steward

import (
	"log"
	"net"
	"net/http"
	"os"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

// metrics are generally used to hold the structure around metrics
// handling
type metrics struct {
	// The channel to pass metrics that should be processed
	promRegistry *prometheus.Registry
	// host and port where prometheus metrics will be exported
	hostAndPort string
}

// newMetrics will prepare and return a *metrics
func newMetrics(hostAndPort string) *metrics {
	m := metrics{
		promRegistry: prometheus.NewRegistry(),
		hostAndPort:  hostAndPort,
	}

	return &m
}

func (s *server) startMetrics() {

	//http.Handle("/metrics", promhttp.Handler())
	//http.ListenAndServe(":2112", nil)
	n, err := net.Listen("tcp", s.metrics.hostAndPort)
	if err != nil {
		log.Printf("error: failed to open prometheus listen port: %v\n", err)
		os.Exit(1)
	}
	m := http.NewServeMux()
	m.Handle("/metrics", promhttp.Handler())
	http.Serve(n, m)
}