http: remove Connection header in ReverseProxy

Fixes #2342

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5302057

diff --git a/src/pkg/http/reverseproxy.go b/src/pkg/http/reverseproxy.go
index 3f8bfdc80c23d8278e5b6ef52f731390f8e801ab..3a63db009fc2c1eb7fe8bcaee5ce2e6129670f3c 100644 (file)
--- a/src/pkg/http/reverseproxy.go
+++ b/src/pkg/http/reverseproxy.go
@@ -69,6 +69,14 @@ func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy {
        return &ReverseProxy{Director: director}
 }
 
+func copyHeader(dst, src Header) {
+       for k, vv := range src {
+               for _, v := range vv {
+                       dst.Add(k, v)
+               }
+       }
+}
+
 func (p *ReverseProxy) ServeHTTP(rw ResponseWriter, req *Request) {
        transport := p.Transport
        if transport == nil {
@@ -84,6 +92,16 @@ func (p *ReverseProxy) ServeHTTP(rw ResponseWriter, req *Request) {
        outreq.ProtoMinor = 1
        outreq.Close = false
 
+       // Remove the connection header to the backend.  We want a
+       // persistent connection, regardless of what the client sent
+       // to us.  This is modifying the same underlying map from req
+       // (shallow copied above) so we only copy it if necessary.
+       if outreq.Header.Get("Connection") != "" {
+               outreq.Header = make(Header)
+               copyHeader(outreq.Header, req.Header)
+               outreq.Header.Del("Connection")
+       }
+
        if clientIp, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
                outreq.Header.Set("X-Forwarded-For", clientIp)
        }
@@ -95,12 +113,7 @@ func (p *ReverseProxy) ServeHTTP(rw ResponseWriter, req *Request) {
                return
        }
 
-       hdr := rw.Header()
-       for k, vv := range res.Header {
-               for _, v := range vv {
-                       hdr.Add(k, v)
-               }
-       }
+       copyHeader(rw.Header(), res.Header)
 
        rw.WriteHeader(res.StatusCode)
 

diff --git a/src/pkg/http/reverseproxy_test.go b/src/pkg/http/reverseproxy_test.go
index 8078c8d10df3b40dcd6cfdc92618c8a7fbe29cb7..663218d61b9950d10d95310176ce970ca656e7fe 100644 (file)
--- a/src/pkg/http/reverseproxy_test.go
+++ b/src/pkg/http/reverseproxy_test.go
@@ -24,6 +24,9 @@ func TestReverseProxy(t *testing.T) {
                if r.Header.Get("X-Forwarded-For") == "" {
                        t.Errorf("didn't get X-Forwarded-For header")
                }
+               if c := r.Header.Get("Connection"); c != "" {
+                       t.Errorf("handler got Connection header value %q", c)
+               }
                if g, e := r.Host, "some-name"; g != e {
                        t.Errorf("backend got Host header %q, want %q", g, e)
                }
@@ -43,6 +46,8 @@ func TestReverseProxy(t *testing.T) {
 
        getReq, _ := NewRequest("GET", frontend.URL, nil)
        getReq.Host = "some-name"
+       getReq.Header.Set("Connection", "close")
+       getReq.Close = true
        res, err := DefaultClient.Do(getReq)
        if err != nil {
                t.Fatalf("Get: %v", err)