Use an environmental variable (XM_SERVER) to determine XML-RPC URI.

This allows users to invoke xm against a remote server.  This is much more
useful though for exercising XML-RPC transports with xm-test though since
xm-test will continue to (mostly) function if the URI is localhost.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

tools/python/xen/xend/XendClient.py

@@ -18,6 +18,7 @@
 #============================================================================
 
 from xen.util.xmlrpclib2 import ServerProxy
+import os
 
 XML_RPC_SOCKET = "/var/run/xend/xmlrpc.sock"
 
@@ -25,4 +26,8 @@ ERROR_INTERNAL = 1
 ERROR_GENERIC = 2
 ERROR_INVALID_DOMAIN = 3
 
-server = ServerProxy('httpu:///var/run/xend/xmlrpc.sock')
+uri = 'httpu:///var/run/xend/xmlrpc.sock'
+if os.environ.has_key('XM_SERVER'):
+    uri = os.environ['XM_SERVER']
+
+server = ServerProxy(uri)