rpc: include structured error information in responses

Include keyword arguments of exceptions in RPC responses. This is limited
to JSON-RPC, as XML-RPC does not support additional data in error
responses.

Include keyword arguments of messages in RPC responses.

Include keyword arguments of exceptions in batch command result.

https://fedorahosted.org/freeipa/ticket/4739

Reviewed-By: David Kupka <dkupka@redhat.com>

ipalib/messages.py

@@ -49,6 +49,12 @@ def add_message(version, result, message):
 
 
 def process_message_arguments(obj, format=None, message=None, **kw):
+    for key, value in kw.items():
+        if not isinstance(value, six.integer_types):
+            try:
+                kw[key] = unicode(value)
+            except UnicodeError:
+                pass
     obj.kw = kw
     name = obj.__class__.__name__
     if obj.format is not None and format is not None:
@@ -120,6 +126,7 @@ class PublicMessage(UserWarning):
             name=unicode(type(self).__name__),
             message=self.strerror,
             code=self.errno,
+            data=self.kw,
         )
 
     if six.PY3:

ipalib/plugins/batch.py

@@ -136,6 +136,7 @@ class batch(Command):
                     error=reported_error.strerror,
                     error_code=reported_error.errno,
                     error_name=unicode(type(reported_error).__name__),
+                    error_kw=reported_error.kw,
                 )
             results.append(result)
         return dict(count=len(results) , results=results)

ipalib/rpc.py

@@ -1097,7 +1097,9 @@ class JSONServerProxy(object):
                     server=self.__host,
                 )
             else:
-                raise error_class(message=error['message'])
+                kw = error.get('data', {})
+                kw['message'] = error['message']
+                raise error_class(**kw)
 
         return response['result']