Merge branch 'master' into 'master'

Ensure that every string key and value of the json response from the network cache server is a str object

Please, @kazuhiko and @kirr, review this.

See merge request !1

slapos/libnetworkcache.py

@@ -49,6 +49,17 @@ class short_exc_info(tuple):
     l = ['%s:%s\n' % (filename, lineno)]
     l += traceback.format_exception_only(t, v)
     return ''.join(l).rstrip()
+    
+def byteify(input):
+  '''Transform every unicode string inside a list or dict into normal strings. '''
+  if isinstance(input, dict):
+    return dict([(byteify(key), byteify(value)) for key, value in input.iteritems()])
+  elif isinstance(input, list):
+    return [byteify(element) for element in input]
+  elif isinstance(input, unicode):
+    return input.encode('utf-8')
+  else:
+    return input
 
 
 class NetworkcacheClient(object):
@@ -263,7 +274,7 @@ class NetworkcacheClient(object):
     data_list = self.select_generic(key, self.signature_certificate_list)
     for information_json, signature in data_list:
       try:
-        information_dict = json.loads(information_json)
+        information_dict = byteify(json.loads(information_json))
       except Exception:
         logger.info('Failed to parse json-in-json response (%r)',
                     information_json)