net/http/httptrace: refer http.Client users to the blog post

Fixes #17152.

Change-Id: I4dd5e505c65f3efe736e46d3781cccf31d7f574f
Reviewed-on: https://go-review.googlesource.com/32117
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/net/http/httptrace/trace.go b/src/net/http/httptrace/trace.go
index 807bc4ed69323781e96a69cd59edb44f50cb65ce..3b7417911fa6cf28ec9b2688818d130483c34007 100644 (file)
--- a/src/net/http/httptrace/trace.go
+++ b/src/net/http/httptrace/trace.go
@@ -70,6 +70,12 @@ func WithClientTrace(ctx context.Context, trace *ClientTrace) context.Context {
 // HTTP request. Any particular hook may be nil. Functions may be
 // called concurrently from different goroutines and some may be called
 // after the request has completed or failed.
+//
+// ClientTrace currently traces a single HTTP request & response
+// during a single round trip and has no hooks that span a series
+// of redirected requests.
+//
+// See https://blog.golang.org/http-tracing for more.
 type ClientTrace struct {
        // GetConn is called before a connection is created or
        // retrieved from an idle pool. The hostPort is the