Add locking around tracer.

It can be called concurrently, and after the request has finished.

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>

diff --git a/prober/http.go b/prober/http.go
index 95d65f14a444d702e0f30669098439f7f4cea97e..bd9722d0f43a2c1866aab07b456bd0f351767753 100644 (file)
--- a/prober/http.go
+++ b/prober/http.go
@@ -28,6 +28,7 @@ import (
        "regexp"
        "strconv"
        "strings"
+       "sync"
        "time"
 
        "github.com/go-kit/kit/log"
@@ -149,8 +150,10 @@ type transport struct {
        NoServerNameTransport http.RoundTripper
        firstHost             string
        logger                log.Logger
-       traces                []*roundTripTrace
-       current               *roundTripTrace
+
+       mu      sync.Mutex
+       traces  []*roundTripTrace
+       current *roundTripTrace
 }
 
 func newTransport(rt, noServerName http.RoundTripper, logger log.Logger) *transport {
@@ -188,12 +191,18 @@ func (t *transport) RoundTrip(req *http.Request) (*http.Response, error) {
 }
 
 func (t *transport) DNSStart(_ httptrace.DNSStartInfo) {
+       t.mu.Lock()
+       defer t.mu.Unlock()
        t.current.start = time.Now()
 }
 func (t *transport) DNSDone(_ httptrace.DNSDoneInfo) {
+       t.mu.Lock()
+       defer t.mu.Unlock()
        t.current.dnsDone = time.Now()
 }
 func (ts *transport) ConnectStart(_, _ string) {
+       ts.mu.Lock()
+       defer ts.mu.Unlock()
        t := ts.current
        // No DNS resolution because we connected to IP directly.
        if t.dnsDone.IsZero() {
@@ -202,12 +211,18 @@ func (ts *transport) ConnectStart(_, _ string) {
        }
 }
 func (t *transport) ConnectDone(net, addr string, err error) {
+       t.mu.Lock()
+       defer t.mu.Unlock()
        t.current.connectDone = time.Now()
 }
 func (t *transport) GotConn(_ httptrace.GotConnInfo) {
+       t.mu.Lock()
+       defer t.mu.Unlock()
        t.current.gotConn = time.Now()
 }
 func (t *transport) GotFirstResponseByte() {
+       t.mu.Lock()
+       defer t.mu.Unlock()
        t.current.responseStart = time.Now()
 }
 
@@ -478,6 +493,8 @@ func ProbeHTTP(ctx context.Context, target string, module config.Module, registr
        if resp == nil {
                resp = &http.Response{}
        }
+       tt.mu.Lock()
+       defer tt.mu.Unlock()
        for i, trace := range tt.traces {
                level.Info(logger).Log(
                        "msg", "Response timings for roundtrip",