freeipa/ipalib/messages.py
Petr Viktorin 24bca144a8 Add client capabilities, enable messages
The API version the client sends can now be used to check what the client
expects or is capable of.

All version tests IPA does will be be named and listed in one module,
ipalib.capabilities, which includes a function to test a specific capability
against an API version.
Similarly to Python's __future__ module, capabilities.py also serves as
documentation of backwards-incompatible changes to the API.

The first capability to be defined is "messages". Recent enough clients can
accept a list of warnings or other info under the "messages" key in the
result dict.

If a JSON client does not send the API version, it is assumed this is a testing
client (e.g. curl from the command line). Such a client "has" all capabilities,
but it will always receive a warning mentioning that forward compatibility
is not guaranteed.
If a XML client does not send the API version, it is assumed it uses the API
version before capabilities were introduced. (This is to keep backwards
compatibility with clients containing bug https://fedorahosted.org/freeipa/ticket/3294)

Whenever a capability is added, the API version must be incremented.
To ensure that, capabilities are written to API.txt and checked by
`makeapi --validate`.

Design page: http://freeipa.org/page/V3/Messages
Ticket: https://fedorahosted.org/freeipa/ticket/2732
2013-02-21 16:26:09 +01:00

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5.1 KiB
Python

# Authors:
# Petr Viktorin <pviktori@redhat.com>
#
# Copyright (C) 2012 Red Hat
# see file 'COPYING' for use and warranty inmsgion
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
Custom message (debug, info, wraning) classes passed through RPC.
These are added to the "messages" entry in a RPC response, and printed to the
user as log messages.
Each message class has a unique numeric "errno" attribute from the 10000-10999
range, so that it does not clash with PublicError numbers.
Messages also have the 'type' argument, set to one of 'debug', 'info',
'warning', 'error'. This determines the severity of themessage.
"""
from inspect import isclass
from ipalib.constants import TYPE_ERROR
from ipalib.text import _ as ugettext
from ipalib.text import Gettext, NGettext
from ipalib.capabilities import client_has_capability
def add_message(version, result, message):
if client_has_capability(version, 'messages'):
result.setdefault('messages', []).append(message.to_dict())
def process_message_arguments(obj, format=None, message=None, **kw):
obj.kw = kw
name = obj.__class__.__name__
if obj.format is not None and format is not None:
raise ValueError(
'non-generic %r needs format=None; got format=%r' % (
name, format)
)
if message is None:
if obj.format is None:
if format is None:
raise ValueError(
'%s.format is None yet format=None, message=None' % name
)
obj.format = format
obj.forwarded = False
obj.msg = obj.format % kw
if isinstance(obj.format, basestring):
obj.strerror = ugettext(obj.format) % kw
else:
obj.strerror = obj.format % kw
if 'instructions' in kw:
def convert_instructions(value):
if isinstance(value, list):
result = u'\n'.join(map(lambda line: unicode(line), value))
return result
return value
instructions = u'\n'.join((unicode(_('Additional instructions:')),
convert_instructions(kw['instructions'])))
obj.strerror = u'\n'.join((obj.strerror, instructions))
else:
if isinstance(message, (Gettext, NGettext)):
message = unicode(message)
elif type(message) is not unicode:
raise TypeError(
TYPE_ERROR % ('message', unicode, message, type(message))
)
obj.forwarded = True
obj.msg = message
obj.strerror = message
for (key, value) in kw.iteritems():
assert not hasattr(obj, key), 'conflicting kwarg %s.%s = %r' % (
name, key, value,
)
setattr(obj, key, value)
_texts = []
def _(message):
_texts.append(message)
return message
class PublicMessage(UserWarning):
"""
**10000** Base class for messages that can be forwarded in an RPC response.
"""
def __init__(self, format=None, message=None, **kw):
process_message_arguments(self, format, message, **kw)
super(PublicMessage, self).__init__(self.msg)
errno = 10000
format = None
def to_dict(self):
"""Export this message to a dict that can be sent through RPC"""
return dict(
type=unicode(self.type),
name=unicode(type(self).__name__),
message=self.strerror,
code=self.errno,
)
class VersionMissing(PublicMessage):
"""
**13001** Used when client did not send the API version.
For example:
>>> VersionMissing(server_version='2.123').strerror
u"API Version number was not sent, forward compatibility not guaranteed. Assuming server's API version, 2.123"
"""
errno = 13001
type = 'warning'
format = _("API Version number was not sent, forward compatibility not "
"guaranteed. Assuming server's API version, %(server_version)s")
def iter_messages(variables, base):
"""Return a tuple with all subclasses
"""
for (key, value) in variables.items():
if key.startswith('_') or not isclass(value):
continue
if issubclass(value, base):
yield value
public_messages = tuple(sorted(
iter_messages(globals(), PublicMessage), key=lambda E: E.errno))
def print_report(label, classes):
for cls in classes:
print '%d\t%s' % (cls.errno, cls.__name__)
print '(%d %s)' % (len(classes), label)
if __name__ == '__main__':
print_report('public messages', public_messages)