renamed sfa/plc into sfa/planetlab

[sfa.git] / sfa / planetlab / plshell.py

diff --git a/sfa/planetlab/plshell.py b/sfa/planetlab/plshell.py
new file mode 100644 (file)
index 0000000..d2cd9cd
--- /dev/null
+++ b/sfa/planetlab/plshell.py
@@ -0,0 +1,86 @@
+import sys
+import xmlrpclib
+import socket
+from urlparse import urlparse
+
+from sfa.util.sfalogging import logger
+
+class PlShell:
+    """
+    A simple xmlrpc shell to a myplc instance
+    This class can receive all PLCAPI calls to the underlying testbed
+    For safety this is limited to a set of hard-coded calls
+    """
+    
+    direct_calls = ['AddNode', 'AddPerson', 'AddPersonKey', 'AddPersonToSite',
+                    'AddPersonToSlice', 'AddRoleToPerson', 'AddSite', 'AddSiteTag', 'AddSlice',
+                    'AddSliceTag', 'AddSliceToNodes', 'BindObjectToPeer', 'DeleteKey',
+                    'DeleteNode', 'DeletePerson', 'DeletePersonFromSlice', 'DeleteSite',
+                    'DeleteSlice', 'DeleteSliceFromNodes', 'DeleteSliceTag', 'GetInitScripts',
+                    'GetInterfaces', 'GetKeys', 'GetNodeTags', 'GetPeers',
+                    'GetPersons', 'GetSlices', 'GetSliceTags', 'GetTagTypes',
+                    'UnBindObjectFromPeer', 'UpdateNode', 'UpdatePerson', 'UpdateSite',
+                    'UpdateSlice', 'UpdateSliceTag',
+                    # also used as-is in importer
+                    'GetSites','GetNodes',
+                    ]
+    # support for other names - this is experimental
+    alias_calls = { 'get_authorities':'GetSites',
+                    'get_nodes':'GetNodes',
+                    }
+
+
+    # use the 'capability' auth mechanism for higher performance when the PLC db is local    
+    def __init__ ( self, config ) :
+        url = config.SFA_PLC_URL
+        # try to figure if the url is local
+        hostname=urlparse(url).hostname
+        is_local=False
+        if hostname == 'localhost': is_local=True
+        # otherwise compare IP addresses; 
+        # this might fail for any number of reasons, so let's harden that
+        try:
+            # xxx todo this seems to result in a DNS request for each incoming request to the AM
+            # should be cached or improved
+            url_ip=socket.gethostbyname(hostname)
+            local_ip=socket.gethostbyname(socket.gethostname())
+            if url_ip==local_ip: is_local=True
+        except:
+            pass
+
+        if is_local:
+            try:
+                # too bad this is not installed properly
+                plcapi_path="/usr/share/plc_api"
+                if plcapi_path not in sys.path: sys.path.append(plcapi_path)
+                import PLC.Shell
+                plc_direct_access=True
+            except:
+                plc_direct_access=False
+        if is_local and plc_direct_access:
+            logger.debug('plshell access - capability')
+            self.plauth = { 'AuthMethod': 'capability',
+                            'Username':   config.SFA_PLC_USER,
+                            'AuthString': config.SFA_PLC_PASSWORD,
+                            }
+            self.proxy = PLC.Shell.Shell ()
+
+        else:
+            logger.debug('plshell access - xmlrpc')
+            self.plauth = { 'AuthMethod': 'password',
+                            'Username':   config.SFA_PLC_USER,
+                            'AuthString': config.SFA_PLC_PASSWORD,
+                            }
+            self.proxy = xmlrpclib.Server(url, verbose = False, allow_none = True)
+
+    def __getattr__(self, name):
+        def func(*args, **kwds):
+            actual_name=None
+            if name in PlShell.direct_calls: actual_name=name
+            if name in PlShell.alias_calls: actual_name=PlShell.alias_calls[name]
+            if not actual_name:
+                raise Exception, "Illegal method call %s for PL driver"%(name)
+            result=getattr(self.proxy, actual_name)(self.plauth, *args, **kwds)
+            logger.debug('PlShell %s (%s) returned ... '%(name,actual_name))
+            return result
+        return func