+def GetSlivers(config, plc):
+ '''Run call backs defined in modules'''
+ try:
+ logger.log("nm: Syncing w/ PLC")
+ # retrieve GetSlivers from PLC
+ data = plc.GetSlivers()
+ # use the magic 'default' slice to retrieve system-wide defaults
+ getPLCDefaults(data, config)
+ # tweak the 'vref' attribute from GetSliceFamily
+ setSliversVref (data)
+ # always dump it for debug purposes
+ # used to be done only in verbose; very helpful though, and tedious to obtain,
+ # so let's dump this unconditionnally
+ logger.log_slivers(data)
+ logger.verbose("nm: Sync w/ PLC done")
+ except:
+ logger.log_exc("nm: failed in GetSlivers")
+ # XXX So some modules can at least boostrap.
+ logger.log("nm: Can't contact PLC to GetSlivers(). Continuing.")
+ data = {}
+ # Invoke GetSlivers() functions from the callback modules
+ for module in modules:
+ try:
+ callback = getattr(module, 'GetSlivers')
+ callback(data, config, plc)
+ except: logger.log_exc("nm: GetSlivers failed to run callback for module %r"%module)
+
+
+def getPLCDefaults(data, config):
+ '''
+ Get PLC wide defaults from _default system slice. Adds them to config class.
+ '''
+ for slice in data.get('slivers'):
+ if slice['name'] == config.PLC_SLICE_PREFIX+"_default":
+ attr_dict = {}
+ for attr in slice.get('attributes'): attr_dict[attr['tagname']] = attr['value']
+ if len(attr_dict):
+ logger.verbose("nm: Found default slice overrides.\n %s" % attr_dict)
+ config.OVERRIDES = attr_dict
+ return
+ # NOTE: if an _default slice existed, it would have been found above and
+ # the routine would return. Thus, if we've gotten here, then no default
+ # slice is bound to this node.
+ if 'OVERRIDES' in dir(config): del config.OVERRIDES
+
+
+def setSliversVref (data):
+ '''
+ Tweak the 'vref' attribute in all slivers based on the 'GetSliceFamily' key
+ '''
+ # GetSlivers exposes the result of GetSliceFamily() as an separate key in data
+ # It is safe to override the attributes with this, as this method has the right logic
+ for sliver in data.get('slivers'):
+ try:
+ slicefamily=sliver.get('GetSliceFamily')
+ for att in sliver['attributes']:
+ if att['tagname']=='vref':
+ att['value']=slicefamily
+ continue
+ sliver['attributes'].append({ 'tagname':'vref','value':slicefamily})
+ except:
+ logger.log_exc("nm: Could not overwrite 'vref' attribute from 'GetSliceFamily'",name=sliver['name'])
+