Keystone Cannot Translate the REST API message returned from exception.py

[hufali]

The doc string in exception.py of Keystone will be returned with __doc__ method, but cannot realize the internationalization.

/v2.0/tokens
{
    "error": {
        "message": "Expecting to find username or userId in passwordCredentials. The server could not comply with the request since it is either malformed or otherwise incorrect. The client is assumed to be in error.",
        "code": 400,
        "title": "Bad Request"
    }
}
{
    "error": {
        "message": "The request you have made requires authentication.",
        "code": 401,
        "title": "Not Authorized"
    }
}
{
    "error": {
        "message": "Invalid user / password",
        "code": 401,
        "title": "Not Authorized"
    }
}
The message in error which should be translated is returned from the doc string in excetpion.py of Keystone.

[David Jia (jiataotj)]

in keystone exception.py, there are a lot of doc string which are used as REST API return messages, those doc string can't be translated to other language, because python doesn't support to directly translate the doc string in the program.Then those messages will be returned as hardcode, it doesn't make sense, since other REST API return messages can be translated,so I think we need modify the exception.py to support i18n

[David Jia (jiataotj)]

As below codes shows,in keystone exception.py, doc string are used as REST API return message

class Error(StandardError):
    """Base error class.

    Child classes should define an HTTP status code, title, and a doc string.

    """
    code = None
    title = None

    def __init__(self, message=None, **kwargs):
        """Use the doc string as the error message by default."""

        try:
            message = self._build_message(message, **kwargs)
        except KeyError as e:
            # if you see this warning in your logs, please raise a bug report
            if _FATAL_EXCEPTION_FORMAT_ERRORS:
                raise e
            else:
                LOG.warning('missing exception kwargs (programmer error)')
                message = self.__doc__

        super(Error, self).__init__(message)
------------------------------------------------------------------------------------------------------------------------------------------------------
Below is a sample class whose doc string will be returnd when the error exist

class ValidationSizeError(Error):
    """Request attribute %(attribute)s must be less than or equal to %(size)i.

    The server could not comply with the request because the attribute
    size is invalid (too large).

    The client is assumed to be in error.

    """
    code = 400
    title = 'Bad Request'

-----------------------------------------------------------------------------------------------------------

we can't wrap doc string using _() to translate them to implement i18n support, we can use message as class variable to replace using doc string to enable return message translation

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29367

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29759

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/31074

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/31074
Committed: http://github.com/openstack/keystone/commit/f976bbe697002367ff00a0588a3181fd42008e1c
Submitter: Jenkins
Branch: master

commit f976bbe697002367ff00a0588a3181fd42008e1c
Author: jiataotj <email address hidden>
Date: Fri May 31 00:18:28 2013 +0800

    Implement exception module i18n support

    The doc string in exception.py of Keystone will be
    returned with __doc__ method, but cannot realize the
    internationalization.Change exception module to enable
    i18n support.

    Changes in the patch are:
    1, useing class variable msg_fmt to replace class __doc__
    2, modify wsgi.render_exception function using unicode
    function to replace str function
    3, modify/add UT test cases

    Fixes: bug # 1179425

    Change-Id: I75c1229c905a2625d2f6961d1a8dd3958eac51a5