sheepdog returns 500 status and non-descriptive error message

[jacquayj]

When creating a project record, if a validation error occurs, a non-descriptive error message ({ "error": "service failure - try again later"}) is returned with a status of 500.

Viewing the pod logs, I get more info:

[2019-09-26 19:21:47,461][sheepdog.api][  ERROR] Value '' not in allowed value list for ['Open', 'Restricted'] for property availability_type.
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/lib/python2.7/site-packages/flask/app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/sheepdog/sheepdog/utils/__init__.py", line 123, in check
    return func(program, *args, **kwargs)
  File "/sheepdog/sheepdog/blueprint/routes/views/program/__init__.py", line 186, in create_project
    node.props.update(base_doc)
  File "/usr/lib/python2.7/site-packages/psqlgraph/attributes.py", line 57, in update
    setattr(self.source, key, val)
  File "/usr/lib/python2.7/site-packages/sqlalchemy/ext/hybrid.py", line 900, in __set__
    self.fset(instance, value)
  File "/usr/lib/python2.7/site-packages/psqlgraph/base.py", line 281, in hybrid_prop
    validate(fset, value, fset.__pg_types__, fset.__pg_enum__)
  File "/usr/lib/python2.7/site-packages/psqlgraph/util.py", line 22, in validate
    ).format(value, enum, f.__name__))

Since this is a user input error, I'd expect a 400 Bad Request response code with errors embedded in the response:

{
   "errors": {
      "availability_type": "Value '' not in allowed value list for ['Open', 'Restricted']"
   }
}

This example response is just a suggestion, but it would be nice to inform the React application of the specific field where an error occurred, so server-side error messages can be rendered on the client. This is beneficial because you don't need to implement client-side validation in addition to server-side.