Set status 503 when backup is in progress. Fixes #5221

Author: ketan

server/src/main/java/com/thoughtworks/go/server/web/BackupFilter.java

@@ -82,6 +82,8 @@ public void doFilter(ServletRequest request, ServletResponse response, FilterCha
             } else {
                 generateHTMLResponse(response);
             }
+
+            ((HttpServletResponse) response).setStatus(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
         } else {
             chain.doFilter(request, response);
         }
@@ -130,7 +132,6 @@ private void generateAPIResponse(ServletRequest request, ServletResponse respons
         } catch (IOException e) {
             LOGGER.error("General IOException: {}", e.getMessage());
         }
-        ((HttpServletResponse) response).setStatus(503);
     }
 
     private boolean requestIsOfType(String type, HttpServletRequest request) {

server/src/test-fast/java/com/thoughtworks/go/server/web/BackupFilterTest.java

@@ -73,6 +73,7 @@ public void shouldPassRequestWhenBackupIsNotBeingTaken() throws Exception {
         backupFilter.doFilter(request, res, chain);
         verify(res, times(0)).setContentType("text/html");
         verify(writer, times(0)).print("some test data for my input stream");
+        verify(res, never()).setStatus(anyInt());
     }
 
     @Test
@@ -91,6 +92,7 @@ public void shouldWriteToResponseWhenBackupIsBeingTaken() throws Exception {
         verify(writer).print(content);
         verify(res).setHeader("Cache-Control", "private, max-age=0, no-cache");
         verify(res).setDateHeader("Expires", 0);
+        verify(res).setStatus(503);
     }
 
     @Test
@@ -109,6 +111,7 @@ public void shouldGenerateHTMLResponseWhenBackupIsBeingTakenAndMessageJsonIsCall
         verify(writer).print(content);
         verify(res).setHeader("Cache-Control", "private, max-age=0, no-cache");
         verify(res).setDateHeader("Expires", 0);
+        verify(res).setStatus(503);
     }
 
 
@@ -127,6 +130,7 @@ public void shouldReturnJsonResponseWhenBackupIsFinishedJsonAPIIsBeingCalled() t
         verify(writer).print(json);
         verify(res).setHeader("Cache-Control", "private, max-age=0, no-cache");
         verify(res).setDateHeader("Expires", 0);
+        verify(res, never()).setStatus(anyInt());
     }
 
     @Test
@@ -162,6 +166,7 @@ private void assertResponse(JsonObject json) {
         verify(writer).print(json);
         verify(res).setHeader("Cache-Control", "private, max-age=0, no-cache");
         verify(res).setDateHeader("Expires", 0);
+        verify(res).setStatus(503);
     }
 
     private Request request(HttpMethod method, String contentType, String uri) {