Updates CLMC to always set the HTTP Accept header to application/json -...

Updates CLMC to always set the HTTP Accept header to application/json - otherwise, error messages might be sent as HTML

src/service/clmcservice/__init__.py

@@ -60,6 +60,8 @@ def main(global_config, **settings):
 
     config = Configurator(settings=settings)
 
+    config.add_tween('clmcservice.tweens.accept_header_tween_factory')
+
     # add routes of the WHOAMI API
     config.add_route('whoami_endpoints', '/whoami/endpoints')
     config.add_route('whoami_endpoints_instance', 'whoami/endpoints/instance')

src/service/clmcservice/tweens.py

+#!/usr/bin/python3
+"""
+// © University of Southampton IT Innovation Centre, 2018
+//
+// Copyright in this software belongs to University of Southampton
+// IT Innovation Centre of Gamma House, Enterprise Road,
+// Chilworth Science Park, Southampton, SO16 7NS, UK.
+//
+// This software may not be used, sold, licensed, transferred, copied
+// or reproduced in whole or in part in any manner or form or in or
+// on any media by any person other than in accordance with the terms
+// of the Licence Agreement supplied with the software, or otherwise
+// without the prior written consent of the copyright owners.
+//
+// This software is distributed WITHOUT ANY WARRANTY, without even the
+// implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+// PURPOSE, except where stated in the Licence Agreement supplied with
+// the software.
+//
+//      Created By :            Nikolay Stanchev
+//      Created Date :          02-11-2018
+//      Created for Project :   FLAME
+"""
+
+
+def accept_header_tween_factory(handler, registry):
+    """
+    Since clmc-service is currently based on JSON only, make sure an application/json header is passed with the request
+    """
+
+    def accept_header_tween(request):
+        request.accept = 'application/json'
+        response = handler(request)
+        return response
+
+    return accept_header_tween