cloudflare/cloudflared
Publicmirrored from https://github.com/cloudflare/cloudflaredAvailable
metrics/metrics.go
76lines · modecode
| 1 | package metrics |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "net" |
| 7 | "net/http" |
| 8 | _ "net/http/pprof" |
| 9 | "runtime" |
| 10 | "sync" |
| 11 | "time" |
| 12 | |
| 13 | "golang.org/x/net/trace" |
| 14 | |
| 15 | "github.com/prometheus/client_golang/prometheus" |
| 16 | "github.com/prometheus/client_golang/prometheus/promhttp" |
| 17 | "github.com/sirupsen/logrus" |
| 18 | ) |
| 19 | |
| 20 | const ( |
| 21 | shutdownTimeout = time.Second * 15 |
| 22 | startupTime = time.Millisecond * 500 |
| 23 | ) |
| 24 | |
| 25 | func ServeMetrics(l net.Listener, shutdownC <-chan struct{}, logger *logrus.Logger) (err error) { |
| 26 | var wg sync.WaitGroup |
| 27 | // Metrics port is privileged, so no need for further access control |
| 28 | trace.AuthRequest = func(*http.Request) (bool, bool) { return true, true } |
| 29 | // TODO: parameterize ReadTimeout and WriteTimeout. The maximum time we can |
| 30 | // profile CPU usage depends on WriteTimeout |
| 31 | server := &http.Server{ |
| 32 | ReadTimeout: 10 * time.Second, |
| 33 | WriteTimeout: 10 * time.Second, |
| 34 | } |
| 35 | |
| 36 | http.Handle("/metrics", promhttp.Handler()) |
| 37 | http.Handle("/healthcheck", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 38 | fmt.Fprintf(w, "OK\n") |
| 39 | })) |
| 40 | |
| 41 | wg.Add(1) |
| 42 | go func() { |
| 43 | defer wg.Done() |
| 44 | err = server.Serve(l) |
| 45 | }() |
| 46 | logger.WithField("addr", l.Addr()).Info("Starting metrics server") |
| 47 | // server.Serve will hang if server.Shutdown is called before the server is |
| 48 | // fully started up. So add artificial delay. |
| 49 | time.Sleep(startupTime) |
| 50 | |
| 51 | <-shutdownC |
| 52 | ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout) |
| 53 | server.Shutdown(ctx) |
| 54 | cancel() |
| 55 | |
| 56 | wg.Wait() |
| 57 | if err == http.ErrServerClosed { |
| 58 | logger.Info("Metrics server stopped") |
| 59 | return nil |
| 60 | } |
| 61 | logger.WithError(err).Error("Metrics server quit with error") |
| 62 | return err |
| 63 | } |
| 64 | |
| 65 | func RegisterBuildInfo(buildTime string, version string) { |
| 66 | buildInfo := prometheus.NewGaugeVec( |
| 67 | prometheus.GaugeOpts{ |
| 68 | // Don't namespace build_info, since we want it to be consistent across all Cloudflare services |
| 69 | Name: "build_info", |
| 70 | Help: "Build and version information", |
| 71 | }, |
| 72 | []string{"goversion", "revision", "version"}, |
| 73 | ) |
| 74 | prometheus.MustRegister(buildInfo) |
| 75 | buildInfo.WithLabelValues(runtime.Version(), buildTime, version).Set(1) |
| 76 | } |
| 77 | |