From 081b81d170e2df4e0cc66ca6a4ead07aeead5e9b Mon Sep 17 00:00:00 2001
From: Roland Shoemaker <rolandshoemaker@gmail.com>
Date: Sat, 26 Sep 2015 18:01:03 -0700
Subject: [PATCH] Add a facebookgo/stats client that sends StatsD metrics for
 facebookgo/httpdown

---
 cmd/boulder-wfe/main.go    |  6 ++--
 cmd/ocsp-responder/main.go |  6 ++--
 metrics/metrics.go         | 68 +++++++++++++++++++++++++++-----------
 3 files changed, 55 insertions(+), 25 deletions(-)

diff --git a/cmd/boulder-wfe/main.go b/cmd/boulder-wfe/main.go
index e100ff9c5..d0892da87 100644
--- a/cmd/boulder-wfe/main.go
+++ b/cmd/boulder-wfe/main.go
@@ -126,14 +126,14 @@ func main() {
 
 		auditlogger.Info(fmt.Sprintf("Server running, listening on %s...\n", c.WFE.ListenAddress))
 		srv := &http.Server{
-			Addr:      c.WFE.ListenAddress,
-			ConnState: httpMonitor.ConnectionMonitor,
-			Handler:   httpMonitor.Handle(),
+			Addr:    c.WFE.ListenAddress,
+			Handler: httpMonitor.Handle(),
 		}
 
 		hd := &httpdown.HTTP{
 			StopTimeout: wfe.ShutdownStopTimeout,
 			KillTimeout: wfe.ShutdownKillTimeout,
+			Stats:       metrics.NewFBAdapter(stats, "WFE"),
 		}
 		err = httpdown.ListenAndServe(srv, hd)
 		cmd.FailOnError(err, "Error starting HTTP server")
diff --git a/cmd/ocsp-responder/main.go b/cmd/ocsp-responder/main.go
index 02e1c6724..4a15564c0 100644
--- a/cmd/ocsp-responder/main.go
+++ b/cmd/ocsp-responder/main.go
@@ -174,14 +174,14 @@ func main() {
 
 		httpMonitor := metrics.NewHTTPMonitor(stats, m, "OCSP")
 		srv := &http.Server{
-			Addr:      c.OCSPResponder.ListenAddress,
-			ConnState: httpMonitor.ConnectionMonitor,
-			Handler:   httpMonitor.Handle(),
+			Addr:    c.OCSPResponder.ListenAddress,
+			Handler: httpMonitor.Handle(),
 		}
 
 		hd := &httpdown.HTTP{
 			StopTimeout: stopTimeout,
 			KillTimeout: killTimeout,
+			Stats:       metrics.NewFBAdapter(stats, "OCSP"),
 		}
 		err = httpdown.ListenAndServe(srv, hd)
 		cmd.FailOnError(err, "Error starting HTTP server")
diff --git a/metrics/metrics.go b/metrics/metrics.go
index 96bf86639..0d1d031b2 100644
--- a/metrics/metrics.go
+++ b/metrics/metrics.go
@@ -7,7 +7,6 @@ package metrics
 
 import (
 	"fmt"
-	"net"
 	"net/http"
 	"strings"
 	"sync/atomic"
@@ -22,7 +21,6 @@ type HTTPMonitor struct {
 	statsPrefix         string
 	handler             http.Handler
 	connectionsInFlight int64
-	openConnections     int64
 }
 
 // NewHTTPMonitor returns a new initialized HTTPMonitor
@@ -32,26 +30,9 @@ func NewHTTPMonitor(stats statsd.Statter, handler http.Handler, prefix string) H
 		handler:             handler,
 		statsPrefix:         prefix,
 		connectionsInFlight: 0,
-		openConnections:     0,
 	}
 }
 
-// ConnectionMonitor provides states on open connection state
-func (h *HTTPMonitor) ConnectionMonitor(_ net.Conn, state http.ConnState) {
-	var open int64
-	switch state {
-	case http.StateNew:
-		open = atomic.AddInt64(&h.openConnections, 1)
-	case http.StateHijacked:
-		fallthrough
-	case http.StateClosed:
-		open = atomic.AddInt64(&h.openConnections, -1)
-	default:
-		return
-	}
-	h.stats.Gauge(fmt.Sprintf("%s.HTTP.OpenConnections", h.statsPrefix), open, 1.0)
-}
-
 // Handle wraps handlers and records various metrics about requests to these handlers
 // and sends them to StatsD
 func (h *HTTPMonitor) Handle() http.Handler {
@@ -85,3 +66,52 @@ func (h *HTTPMonitor) watchAndServe(w http.ResponseWriter, r *http.Request) {
 	}
 	h.stats.TimingDuration(fmt.Sprintf("%s.HTTP.ResponseTime.%s", h.statsPrefix, endpoint), cClosed, 1.0)
 }
+
+// FBAdapter provides a facebookgo/stats client interface that sends metrics via
+// a StatsD client
+type FBAdapter struct {
+	stats  statsd.Statter
+	prefix string
+}
+
+// NewFBAdapter returns a new adapter
+func NewFBAdapter(stats statsd.Statter, prefix string) FBAdapter {
+	return FBAdapter{stats: stats, prefix: prefix}
+}
+
+// BumpAvg is essentially statsd.Statter.Gauge
+func (fba FBAdapter) BumpAvg(key string, val float64) {
+	fba.stats.Gauge(fmt.Sprintf("%s.%s", fba.prefix, key), int64(val), 1.0)
+}
+
+// BumpSum is essentially statsd.Statter.Inc (httpdown only ever uses positive
+// deltas)
+func (fba FBAdapter) BumpSum(key string, val float64) {
+	fba.stats.Inc(fmt.Sprintf("%s.%s", fba.prefix, key), int64(val), 1.0)
+}
+
+type btHolder struct {
+	key     string
+	stats   statsd.Statter
+	started time.Time
+}
+
+func (bth btHolder) End() {
+	bth.stats.TimingDuration(bth.key, time.Since(bth.started), 1.0)
+}
+
+// BumpTime is essentially a (much better) statsd.Statter.TimingDuration
+func (fba FBAdapter) BumpTime(key string) interface {
+	End()
+} {
+	return btHolder{
+		key:     fmt.Sprintf("%s.%s", fba.prefix, key),
+		started: time.Now(),
+		stats:   fba.stats,
+	}
+}
+
+// BumpHistogram isn't used by facebookgo/httpdown
+func (fba FBAdapter) BumpHistogram(_ string, _ float64) {
+	return
+}