Read error from failed upgrade attempts

pkg/client/unversioned/remotecommand/remotecommand.go

@@ -130,10 +130,6 @@ func (e *streamExecutor) Dial(protocols ...string) (httpstream.Connection, strin
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode != http.StatusSwitchingProtocols {
-		return nil, "", fmt.Errorf("unexpected response status code %d (%s)", resp.StatusCode, http.StatusText(resp.StatusCode))
-	}
-
 	conn, err := e.upgrader.NewConnection(resp)
 	if err != nil {
 		return nil, "", err

pkg/util/httpstream/spdy/roundtripper.go

@@ -205,7 +205,7 @@ func (s *SpdyRoundTripper) RoundTrip(req *http.Request) (*http.Response, error)
 func (s *SpdyRoundTripper) NewConnection(resp *http.Response) (httpstream.Connection, error) {
 	connectionHeader := strings.ToLower(resp.Header.Get(httpstream.HeaderConnection))
 	upgradeHeader := strings.ToLower(resp.Header.Get(httpstream.HeaderUpgrade))
-	if !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(HeaderSpdy31)) {
+	if (resp.StatusCode != http.StatusSwitchingProtocols) || !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(HeaderSpdy31)) {
 		defer resp.Body.Close()
 		responseError := ""
 		responseErrorBytes, err := ioutil.ReadAll(resp.Body)

pkg/util/httpstream/spdy/roundtripper_test.go

@@ -39,30 +39,42 @@ func TestRoundTripAndNewConnection(t *testing.T) {
 		clientTLS              *tls.Config
 		serverConnectionHeader string
 		serverUpgradeHeader    string
+		serverStatusCode       int
 		shouldError            bool
 	}{
 		"no headers": {
 			serverFunc:             httptest.NewServer,
 			serverConnectionHeader: "",
 			serverUpgradeHeader:    "",
+			serverStatusCode:       http.StatusSwitchingProtocols,
 			shouldError:            true,
 		},
 		"no upgrade header": {
 			serverFunc:             httptest.NewServer,
 			serverConnectionHeader: "Upgrade",
 			serverUpgradeHeader:    "",
+			serverStatusCode:       http.StatusSwitchingProtocols,
 			shouldError:            true,
 		},
 		"no connection header": {
 			serverFunc:             httptest.NewServer,
 			serverConnectionHeader: "",
 			serverUpgradeHeader:    "SPDY/3.1",
+			serverStatusCode:       http.StatusSwitchingProtocols,
+			shouldError:            true,
+		},
+		"no switching protocol status code": {
+			serverFunc:             httptest.NewServer,
+			serverConnectionHeader: "Upgrade",
+			serverUpgradeHeader:    "SPDY/3.1",
+			serverStatusCode:       http.StatusForbidden,
 			shouldError:            true,
 		},
 		"http": {
 			serverFunc:             httptest.NewServer,
 			serverConnectionHeader: "Upgrade",
 			serverUpgradeHeader:    "SPDY/3.1",
+			serverStatusCode:       http.StatusSwitchingProtocols,
 			shouldError:            false,
 		},
 		"https (invalid hostname + InsecureSkipVerify)": {
@@ -81,6 +93,7 @@ func TestRoundTripAndNewConnection(t *testing.T) {
 			clientTLS:              &tls.Config{InsecureSkipVerify: true},
 			serverConnectionHeader: "Upgrade",
 			serverUpgradeHeader:    "SPDY/3.1",
+			serverStatusCode:       http.StatusSwitchingProtocols,
 			shouldError:            false,
 		},
 		"https (valid hostname + RootCAs)": {
@@ -99,6 +112,7 @@ func TestRoundTripAndNewConnection(t *testing.T) {
 			clientTLS:              &tls.Config{RootCAs: localhostPool},
 			serverConnectionHeader: "Upgrade",
 			serverUpgradeHeader:    "SPDY/3.1",
+			serverStatusCode:       http.StatusSwitchingProtocols,
 			shouldError:            false,
 		},
 	}
@@ -112,7 +126,7 @@ func TestRoundTripAndNewConnection(t *testing.T) {
 
 				w.Header().Set(httpstream.HeaderConnection, testCase.serverConnectionHeader)
 				w.Header().Set(httpstream.HeaderUpgrade, testCase.serverUpgradeHeader)
-				w.WriteHeader(http.StatusSwitchingProtocols)
+				w.WriteHeader(testCase.serverStatusCode)
 
 				return
 			}