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

6 files changed, 112 insertions, 6 deletions

diff --git a/tests/test_ipalib/test_capabilities.py b/tests/test_ipalib/test_capabilities.py
new file mode 100644
index 000000000..21e53c2dc
--- /dev/null
+++ b/tests/test_ipalib/test_capabilities.py
@@ -0,0 +1,33 @@
+# Authors:
+#   Petr Viktorin <pviktori@redhat.com>
+#
+# Copyright (C) 2012  Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# 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/>.
+
+"""
+Test the `ipalib.errors` module.
+"""
+
+from ipalib.capabilities import capabilities, client_has_capability
+
+
+def test_client_has_capability():
+    assert capabilities['messages'] == u'2.52'
+    assert client_has_capability(u'2.52', 'messages')
+    assert client_has_capability(u'2.60', 'messages')
+    assert client_has_capability(u'3.0', 'messages')
+    assert not client_has_capability(u'2.11', 'messages')
+    assert not client_has_capability(u'0.1', 'messages')
diff --git a/tests/test_ipalib/test_frontend.py b/tests/test_ipalib/test_frontend.py
index 4b4735599..3a540608d 100644
--- a/tests/test_ipalib/test_frontend.py
+++ b/tests/test_ipalib/test_frontend.py
@@ -27,7 +27,7 @@ from tests.util import assert_equal
 from ipalib.constants import TYPE_ERROR
 from ipalib.base import NameSpace
 from ipalib import frontend, backend, plugable, errors, parameters, config
-from ipalib import output
+from ipalib import output, messages
 from ipalib.parameters import Str
 from ipapython.version import API_VERSION
 
@@ -619,6 +619,47 @@ class test_Command(ClassChecker):
         assert o.run.im_func is self.cls.run.im_func
         assert ('forward', args, kw) == o.run(*args, **kw)
 
+    def test_messages(self):
+        """
+        Test correct handling of messages
+        """
+        class TestMessage(messages.PublicMessage):
+            type = 'info'
+            format = 'This is a message.'
+            errno = 1234
+
+        class my_cmd(self.cls):
+            def execute(self, *args, **kw):
+                result = {'name': 'execute'}
+                messages.add_message(kw['version'], result, TestMessage())
+                return result
+
+            def forward(self, *args, **kw):
+                result = {'name': 'forward'}
+                messages.add_message(kw['version'], result, TestMessage())
+                return result
+
+        args = ('Hello,', 'world,')
+        kw = dict(how_are='you', on_this='fine day?', version=API_VERSION)
+
+        expected = [TestMessage().to_dict()]
+
+        # Test in server context:
+        (api, home) = create_test_api(in_server=True)
+        api.finalize()
+        o = my_cmd()
+        o.set_api(api)
+        assert o.run.im_func is self.cls.run.im_func
+        assert {'name': 'execute', 'messages': expected} == o.run(*args, **kw)
+
+        # Test in non-server context
+        (api, home) = create_test_api(in_server=False)
+        api.finalize()
+        o = my_cmd()
+        o.set_api(api)
+        assert o.run.im_func is self.cls.run.im_func
+        assert {'name': 'forward', 'messages': expected} == o.run(*args, **kw)
+
     def test_validate_output_basic(self):
         """
         Test the `ipalib.frontend.Command.validate_output` method.
diff --git a/tests/test_ipalib/test_messages.py b/tests/test_ipalib/test_messages.py
index d6a4b9aa1..ebc400ee2 100644
--- a/tests/test_ipalib/test_messages.py
+++ b/tests/test_ipalib/test_messages.py
@@ -22,6 +22,7 @@ Test the `ipalib.messages` module.
 """
 
 from ipalib import messages
+from ipalib.capabilities import capabilities
 from tests.test_ipalib import test_errors
 
 
@@ -58,3 +59,31 @@ def test_to_dict():
     )
 
     assert HelloMessage(greeting='Hello', object='world').to_dict() == expected
+
+
+def test_add_message():
+    result = {}
+
+    assert capabilities['messages'] == u'2.52'
+
+    messages.add_message(u'2.52', result,
+                         HelloMessage(greeting='Hello', object='world'))
+    messages.add_message(u'2.1', result,
+                         HelloMessage(greeting="'Lo", object='version'))
+    messages.add_message(u'2.60', result,
+                         HelloMessage(greeting='Hi', object='version'))
+
+    assert result == {'messages': [
+        dict(
+            name='HelloMessage',
+            type='info',
+            message='Hello, world!',
+            code=1234,
+        ),
+        dict(
+            name='HelloMessage',
+            type='info',
+            message='Hi, version!',
+            code=1234,
+        )
+    ]}
diff --git a/tests/test_xmlrpc/test_ping_plugin.py b/tests/test_xmlrpc/test_ping_plugin.py
index 284aed54f..3673b436f 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 50630a0f9..a61db23d5 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 0a046b454..89a653088 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):