Add API version and have server reject incompatible clients.

This patch contains 2 parts.

The first part is a small utility to create and validate the current
API. To do this it needs to load ipalib which on a fresh system
introduces a few problems, namely that it relies on a python plugin
to set the default encoding to utf8. For our purposes we can skip that.
It is also important that any optional plugins be loadable so the
API can be examined.

The second part is a version exchange between the client and server.
The version has a major and a minor version. The major verion is
updated whenever existing API changes. The minor version is updated when
new API is added. A request will be rejected if either the major versions
don't match or if the client major version is higher than then server
major version (though by implication new API would return a command not
found if allowed to proceed).

To determine the API version of the server from a client use the ping
command.

ticket 584

1 files changed, 14 insertions, 0 deletions

diff --git a/VERSION b/VERSION
index c956ad003..d5b55d0d3 100644
--- a/VERSION
+++ b/VERSION
@@ -66,3 +66,17 @@ IPA_VERSION_IS_GIT_SNAPSHOT="yes"
 #  ->  "20100614120000"                                #
 ########################################################
 IPA_DATA_VERSION=20100614120000
+
+########################################################
+# The version of the IPA API. This controls which      #
+# client versions can use the XML-RPC and json APIs    #
+#                                                      #
+# A change to existing API requires a MAJOR version    #
+# update.  The addition of new API bumps the MINOR     #
+# version.                                             #
+#                                                      #
+# The format is a whole number                         #
+#                                                      #
+########################################################
+IPA_API_VERSION_MAJOR=2
+IPA_API_VERSION_MINOR=0