Switch client to JSON-RPC

Modify ipalib.rpc to support JSON-RPC in addition to XML-RPC.
This is done by subclassing and extending xmlrpclib, because
our existing code relies on xmlrpclib internals.

The URI to use is given in the new jsonrpc_uri env variable. When
it is not given, it is generated from xmlrpc_uri by replacing
/xml with /json.

The rpc_json_uri env variable existed before, but was unused,
undocumented and not set the install scripts.
This patch removes it in favor of jsonrpc_uri (for consistency
with xmlrpc_uri).

Add the rpc_protocol env variable to control the protocol
IPA uses. rpc_protocol defaults to 'jsonrpc', but may be changed
to 'xmlrpc'.
Make backend.Executioner and tests use the backend specified by
rpc_protocol.

For compatibility with unwrap_xml, decoding JSON now gives tuples
instead of lists.

Design: http://freeipa.org/page/V3/JSON-RPC
Ticket: https://fedorahosted.org/freeipa/ticket/3299

1 files changed, 24 insertions, 3 deletions

diff --git a/ipalib/plugins/xmlclient.py b/ipalib/plugins/rpcclient.py
index 21ba47e2..6010b8dd 100644
--- a/ipalib/plugins/xmlclient.py
+++ b/ipalib/plugins/rpcclient.py
@@ -1,8 +1,9 @@
 # Authors:
 #   Jason Gerard DeRose <jderose@redhat.com>
 #   Rob Crittenden <rcritten@redhat.com>
+#   Petr Viktorin <pviktori@redhat.com>
 #
-# Copyright (C) 2008  Red Hat
+# Copyright (C) 2008-2013  Red Hat
 # see file 'COPYING' for use and warranty information
 #
 # This program is free software; you can redistribute it and/or modify
@@ -19,11 +20,31 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 """
-XML-RPC client plugin.
+RPC client plugins.
 """
 
 from ipalib import api
 
 if 'in_server' in api.env and api.env.in_server is False:
-    from ipalib.rpc import xmlclient
+    from ipalib.rpc import xmlclient, jsonclient
     api.register(xmlclient)
+    api.register(jsonclient)
+
+    # FIXME: api.register only looks at the class name, so we need to create
+    # trivial subclasses with the desired name.
+    if api.env.rpc_protocol == 'xmlrpc':
+
+        class rpcclient(xmlclient):
+            """xmlclient renamed to 'rpcclient'"""
+            pass
+        api.register(rpcclient)
+
+    elif api.env.rpc_protocol == 'jsonrpc':
+
+        class rpcclient(jsonclient):
+            """jsonclient renamed to 'rpcclient'"""
+            pass
+        api.register(rpcclient)
+
+    else:
+        raise ValueError('unknown rpc_protocol: %s' % api.env.rpc_protocol)