fix apiserver aggregator bug

staging/src/k8s.io/kube-aggregator/pkg/apiserver/handler_proxy.go

@@ -142,6 +142,7 @@ func (r *proxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	newReq := req.WithContext(context.Background())
 	newReq.Header = utilnet.CloneHeader(req.Header)
 	newReq.URL = location
+	newReq.Host = location.Host
 
 	if handlingInfo.proxyRoundTripper == nil {
 		proxyError(w, req, "", http.StatusNotFound)

staging/src/k8s.io/kube-aggregator/pkg/apiserver/handler_proxy_test.go

@@ -42,18 +42,21 @@ type targetHTTPHandler struct {
 	called  bool
 	headers map[string][]string
 	path    string
+	host    string
 }
 
 func (d *targetHTTPHandler) Reset() {
 	d.path = ""
 	d.called = false
 	d.headers = nil
+	d.host = ""
 }
 
 func (d *targetHTTPHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	d.path = r.URL.Path
 	d.called = true
 	d.headers = r.Header
+	d.host = r.Host
 	w.WriteHeader(http.StatusOK)
 }
 
@@ -258,6 +261,38 @@ func TestProxyHandler(t *testing.T) {
 			},
 			expectedStatusCode: http.StatusServiceUnavailable,
 		},
+		"change aggregator http request host": {
+			user: &user.DefaultInfo{
+				Name:   "username",
+				Groups: []string{"one", "two"},
+			},
+			path: "/request/path",
+			apiService: &apiregistration.APIService{
+				ObjectMeta: metav1.ObjectMeta{Name: "v1.foo"},
+				Spec: apiregistration.APIServiceSpec{
+					Service:               &apiregistration.ServiceReference{},
+					Group:                 "foo",
+					Version:               "v1",
+					InsecureSkipTLSVerify: true,
+				},
+				Status: apiregistration.APIServiceStatus{
+					Conditions: []apiregistration.APIServiceCondition{
+						{Type: apiregistration.Available, Status: apiregistration.ConditionTrue},
+					},
+				},
+			},
+			expectedStatusCode: http.StatusOK,
+			expectedCalled:     true,
+			expectedHeaders: map[string][]string{
+				"X-Forwarded-Proto": {"https"},
+				"X-Forwarded-Uri":   {"/request/path"},
+				"X-Forwarded-For":   {"127.0.0.1"},
+				"X-Remote-User":     {"username"},
+				"User-Agent":        {"Go-http-client/1.1"},
+				"Accept-Encoding":   {"gzip"},
+				"X-Remote-Group":    {"one", "two"},
+			},
+		},
 	}
 
 	for name, tc := range tests {
@@ -313,6 +348,10 @@ func TestProxyHandler(t *testing.T) {
 				t.Errorf("%s: expected %v, got %v", name, e, a)
 				return
 			}
+			if e, a := targetServer.Listener.Addr().String(), target.host; tc.expectedCalled && !reflect.DeepEqual(e, a) {
+				t.Errorf("%s: expected %v, got %v", name, e, a)
+				return
+			}
 		}()
 	}
 }