Check content-type on response

Author: detiber

cluster-autoscaler/cloudprovider/packet/packet_manager_rest.go

@@ -45,7 +45,10 @@ import (
 	schedulerframework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
 )
 
-const userAgent = "kubernetes/cluster-autoscaler/" + version.ClusterAutoscalerVersion
+const (
+	userAgent                    = "kubernetes/cluster-autoscaler/" + version.ClusterAutoscalerVersion
+	expectedAPIContentTypePrefix = "application/json"
+)
 
 type instanceType struct {
 	InstanceName string
@@ -368,6 +371,13 @@ func (mgr *packetManagerRest) request(ctx context.Context, method, url string, j
 		return nil, fmt.Errorf("failed to read response body: %w", err)
 	}
 
+	ct := resp.Header.Get("Content-Type")
+	if !strings.HasPrefix(ct, expectedAPIContentTypePrefix) {
+		errorResponse := &ErrorResponse{Response: resp}
+		errorResponse.SingleError = fmt.Sprintf("Unexpected Content-Type: %s with status: %s", ct, resp.Status)
+		return nil, errorResponse
+	}
+
 	// If the response is good return early
 	if resp.StatusCode >= 200 && resp.StatusCode < 300 {
 		return body, nil

cluster-autoscaler/cloudprovider/packet/packet_manager_rest_test.go

@@ -77,7 +77,7 @@ func newTestPacketManagerRest(t *testing.T, url string) *packetManagerRest {
 }
 func TestListPacketDevices(t *testing.T) {
 	var m *packetManagerRest
-	server := NewHttpServerMock()
+	server := NewHttpServerMockWithContentType()
 	defer server.Close()
 	if len(os.Getenv("PACKET_AUTH_TOKEN")) > 0 {
 		// If auth token set in env, hit the actual Packet API
@@ -87,7 +87,7 @@ func TestListPacketDevices(t *testing.T) {
 		m = newTestPacketManagerRest(t, server.URL)
 		t.Logf("server URL: %v", server.URL)
 		t.Logf("default packetManagerNodePool baseURL: %v", m.packetManagerNodePools["default"].baseURL)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(listPacketDevicesResponse).Times(2)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", listPacketDevicesResponse).Times(2)
 	}
 
 	_, err := m.listPacketDevices(context.TODO())

cluster-autoscaler/cloudprovider/packet/packet_node_group_test.go

@@ -37,7 +37,7 @@ const deletePacketDeviceResponsePool3 = ``
 
 func TestIncreaseDecreaseSize(t *testing.T) {
 	var m *packetManagerRest
-	server := NewHttpServerMock()
+	server := NewHttpServerMockWithContentType()
 	defer server.Close()
 	assert.Equal(t, true, true)
 	if len(os.Getenv("PACKET_AUTH_TOKEN")) > 0 {
@@ -46,15 +46,15 @@ func TestIncreaseDecreaseSize(t *testing.T) {
 	} else {
 		// Set up a mock Packet API
 		m = newTestPacketManagerRest(t, server.URL)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(listPacketDevicesResponse).Times(3)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(createPacketDeviceResponsePool3).Times(1)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(listPacketDevicesResponseAfterIncreasePool3).Times(2)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(createPacketDeviceResponsePool2).Times(1)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(listPacketDevicesResponseAfterIncreasePool2).Times(3)
-		server.On("handle", "/devices/0f5609af-1c27-451b-8edd-a1283f2c9440").Return(deletePacketDeviceResponsePool2).Times(1)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(listPacketDevicesResponseAfterIncreasePool3).Times(3)
-		server.On("handle", "/devices/8fa90049-e715-4794-ba31-81c1c78cee84").Return(deletePacketDeviceResponsePool3).Times(1)
-		server.On("handle", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return(listPacketDevicesResponse).Times(3)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", listPacketDevicesResponse).Times(3)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", createPacketDeviceResponsePool3).Times(1)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", listPacketDevicesResponseAfterIncreasePool3).Times(2)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", createPacketDeviceResponsePool2).Times(1)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", listPacketDevicesResponseAfterIncreasePool2).Times(3)
+		server.On("handleWithContentType", "/devices/0f5609af-1c27-451b-8edd-a1283f2c9440").Return("application/json", deletePacketDeviceResponsePool2).Times(1)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", listPacketDevicesResponseAfterIncreasePool3).Times(3)
+		server.On("handleWithContentType", "/devices/8fa90049-e715-4794-ba31-81c1c78cee84").Return("application/json", deletePacketDeviceResponsePool3).Times(1)
+		server.On("handleWithContentType", "/projects/"+m.packetManagerNodePools["default"].projectID+"/devices").Return("application/json", listPacketDevicesResponse).Times(3)
 	}
 	clusterUpdateLock := sync.Mutex{}
 	ngPool2 := &packetNodeGroup{

cluster-autoscaler/utils/test/test_utils.go

@@ -258,3 +258,24 @@ func (l *HttpServerMock) handleWithStatusCode(url string) (int, string) {
 	args := l.Called(url)
 	return args.Int(0), args.String(1)
 }
+
+// NewHttpServerMockWithContentType creates new HttpServerMock.
+func NewHttpServerMockWithContentType() *HttpServerMock {
+	httpServerMock := &HttpServerMock{}
+	mux := http.NewServeMux()
+	mux.HandleFunc("/",
+		func(w http.ResponseWriter, req *http.Request) {
+			contentType, result := httpServerMock.handleWithContentType(req.URL.Path)
+			w.Header().Set("Content-Type", contentType)
+			_, _ = w.Write([]byte(result))
+		})
+
+	server := httptest.NewServer(mux)
+	httpServerMock.Server = server
+	return httpServerMock
+}
+
+func (l *HttpServerMock) handleWithContentType(url string) (string, string) {
+	args := l.Called(url)
+	return args.String(0), args.String(1)
+}