TUN-528: Move cloudflared into a separate repo

metrics/config.go

@@ -0,0 +1,7 @@
+package metrics
+
+type HistogramConfig struct {
+	BucketsStart float64
+	BucketsWidth float64
+	BucketsCount int
+}

metrics/metrics.go

@@ -0,0 +1,72 @@
+package metrics
+
+import (
+	"net"
+	"net/http"
+	_ "net/http/pprof"
+	"runtime"
+	"sync"
+	"time"
+
+	"golang.org/x/net/context"
+	"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())
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		err = server.Serve(l)
+	}()
+	logger.WithField("addr", 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)
+}

metrics/timer.go

@@ -0,0 +1,47 @@
+package metrics
+
+import (
+  "time"
+  "github.com/prometheus/client_golang/prometheus"
+)
+
+// Timer assumes the metrics is partitioned by one label
+type Timer struct {
+  startTime   map[string]time.Time
+  metrics     *prometheus.HistogramVec
+  measureUnit time.Duration
+  labelKey    string
+}
+
+func NewTimer(metrics *prometheus.HistogramVec, unit time.Duration, labelKey string) *Timer {
+  return &Timer{
+    startTime:   make(map[string]time.Time),
+    measureUnit: unit,
+    metrics:     metrics,
+    labelKey:    labelKey,
+  }
+}
+
+func (i *Timer) Start(labelVal string) {
+  i.startTime[labelVal] = time.Now()
+}
+
+func (i *Timer) End(labelVal string) time.Duration {
+  if start, ok := i.startTime[labelVal]; ok {
+    return Latency(start, time.Now())
+  }
+  return 0
+}
+
+func (i *Timer) Observe(measurement time.Duration, labelVal string) {
+  metricsLabels := prometheus.Labels{i.labelKey: labelVal}
+  i.metrics.With(metricsLabels).Observe(float64(measurement / i.measureUnit))
+}
+
+func (i *Timer) EndAndObserve(labelVal string) {
+  i.Observe(i.End(labelVal), labelVal)
+}
+
+func Latency(startTime, endTime time.Time) time.Duration {
+  return endTime.Sub(startTime)
+}

metrics/timer_test.go

@@ -0,0 +1,24 @@
+package metrics
+
+import (
+  "testing"
+  "time"
+
+  "github.com/prometheus/client_golang/prometheus"
+  "github.com/stretchr/testify/assert"
+)
+
+func TestEnd(t *testing.T) {
+  m := prometheus.NewHistogramVec(
+    prometheus.HistogramOpts{
+      Namespace: "TestCallLatencyWithoutMeasurement",
+      Name:      "Latency",
+      Buckets: prometheus.LinearBuckets(0, 50, 100),
+    },
+    []string{"key"},
+  )
+  timer := NewTimer(m, time.Millisecond, "key")
+  assert.Equal(t, time.Duration(0), timer.End("dne"))
+  timer.Start("test")
+  assert.NotEqual(t, time.Duration(0), timer.End("test"))
+}