77 lines
2.0 KiB
Go
77 lines
2.0 KiB
Go
package metrics
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"net"
|
|
"net/http"
|
|
_ "net/http/pprof"
|
|
"runtime"
|
|
"sync"
|
|
"time"
|
|
|
|
"golang.org/x/net/trace"
|
|
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
"github.com/prometheus/client_golang/prometheus/promhttp"
|
|
"github.com/sirupsen/logrus"
|
|
)
|
|
|
|
const (
|
|
shutdownTimeout = time.Second * 15
|
|
startupTime = time.Millisecond * 500
|
|
)
|
|
|
|
func ServeMetrics(l net.Listener, shutdownC <-chan struct{}, logger *logrus.Logger) (err error) {
|
|
var wg sync.WaitGroup
|
|
// Metrics port is privileged, so no need for further access control
|
|
trace.AuthRequest = func(*http.Request) (bool, bool) { return true, true }
|
|
// TODO: parameterize ReadTimeout and WriteTimeout. The maximum time we can
|
|
// profile CPU usage depends on WriteTimeout
|
|
server := &http.Server{
|
|
ReadTimeout: 10 * time.Second,
|
|
WriteTimeout: 10 * time.Second,
|
|
}
|
|
|
|
http.Handle("/metrics", promhttp.Handler())
|
|
http.Handle("/healthcheck", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
|
fmt.Fprintf(w, "OK\n")
|
|
}))
|
|
|
|
wg.Add(1)
|
|
go func() {
|
|
defer wg.Done()
|
|
err = server.Serve(l)
|
|
}()
|
|
logger.WithField("addr", fmt.Sprintf("%v/metrics", l.Addr())).Info("Starting metrics server")
|
|
// server.Serve will hang if server.Shutdown is called before the server is
|
|
// fully started up. So add artificial delay.
|
|
time.Sleep(startupTime)
|
|
|
|
<-shutdownC
|
|
ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
|
|
server.Shutdown(ctx)
|
|
cancel()
|
|
|
|
wg.Wait()
|
|
if err == http.ErrServerClosed {
|
|
logger.Info("Metrics server stopped")
|
|
return nil
|
|
}
|
|
logger.WithError(err).Error("Metrics server quit with error")
|
|
return err
|
|
}
|
|
|
|
func RegisterBuildInfo(buildTime string, version string) {
|
|
buildInfo := prometheus.NewGaugeVec(
|
|
prometheus.GaugeOpts{
|
|
// Don't namespace build_info, since we want it to be consistent across all Cloudflare services
|
|
Name: "build_info",
|
|
Help: "Build and version information",
|
|
},
|
|
[]string{"goversion", "revision", "version"},
|
|
)
|
|
prometheus.MustRegister(buildInfo)
|
|
buildInfo.WithLabelValues(runtime.Version(), buildTime, version).Set(1)
|
|
}
|