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

3 files changed, 8 insertions, 5 deletions

diff --git a/tests/test_xmlrpc/test_ping_plugin.py b/tests/test_xmlrpc/test_ping_plugin.py
index 284aed54..3673b436 100644
--- a/tests/test_xmlrpc/test_ping_plugin.py
+++ b/tests/test_xmlrpc/test_ping_plugin.py
@@ -21,9 +21,10 @@
 Test the `ipalib/plugins/ping.py` module, and XML-RPC in general.
 """
 
-from ipalib import api, errors, _
-from tests.util import assert_equal, Fuzzy
+from ipalib import api, errors, messages, _
+from tests.util import Fuzzy
 from xmlrpc_test import Declarative
+from ipapython.version import API_VERSION
 
 
 class test_ping(Declarative):
diff --git a/tests/test_xmlrpc/test_user_plugin.py b/tests/test_xmlrpc/test_user_plugin.py
index 50630a0f..a61db23d 100644
--- a/tests/test_xmlrpc/test_user_plugin.py
+++ b/tests/test_xmlrpc/test_user_plugin.py
@@ -23,11 +23,12 @@
 Test the `ipalib/plugins/user.py` module.
 """
 
-from ipalib import api, errors
+from ipalib import api, errors, messages
 from tests.test_xmlrpc import objectclasses
 from tests.util import assert_equal, assert_not_equal
 from xmlrpc_test import Declarative, fuzzy_digits, fuzzy_uuid, fuzzy_password, fuzzy_string, fuzzy_dergeneralizedtime
 from ipapython.dn import DN
+from ipapython.version import API_VERSION
 
 user1=u'tuser1'
 user2=u'tuser2'
diff --git a/tests/test_xmlrpc/xmlrpc_test.py b/tests/test_xmlrpc/xmlrpc_test.py
index 0a046b45..89a65308 100644
--- a/tests/test_xmlrpc/xmlrpc_test.py
+++ b/tests/test_xmlrpc/xmlrpc_test.py
@@ -25,9 +25,9 @@ import sys
 import socket
 import nose
 from tests.util import assert_deepequal, Fuzzy
-from ipalib import api, request
-from ipalib import errors
+from ipalib import api, request, errors
 from ipalib.x509 import valid_issuer
+from ipapython.version import API_VERSION
 
 
 # Matches a gidnumber like '1391016742'
@@ -271,6 +271,7 @@ class Declarative(XMLRPC_test):
 
     def check(self, nice, desc, command, expected, extra_check=None):
         (cmd, args, options) = command
+        options.setdefault('version', API_VERSION)
         if cmd not in api.Command:
             raise nose.SkipTest('%r not in api.Command' % cmd)
         if isinstance(expected, errors.PublicError):