terom@45: from pvl.syslog.filter import SyslogFilter
terom@45: 
terom@45: import re
terom@45: 
terom@51: import optparse, sys
terom@55: import configobj
terom@51: 
terom@45: import logging; log = logging.getLogger('pvl.syslog.rule')
terom@45: 
terom@51: def parser (parser) :
terom@51:     """
terom@51:         Optparse option group.
terom@51:     """
terom@51: 
terom@51:     syslog_rules = optparse.OptionGroup(parser, "Syslog rules")
terom@51:     
terom@51:     syslog_rules.add_option('--syslog-rules', metavar='FILE',
terom@51:             help="Load syslog rules from file")
terom@51: 
terom@51:     return syslog_rules
terom@51: 
terom@51: def apply (options) :
terom@51:     """
terom@51:         Build SyslogRules from options.
terom@51:     """
terom@51:     
terom@51:     if options.syslog_rules :
terom@55:         return SyslogRule.load(open(options.syslog_rules))
terom@51: 
terom@51:     else :
terom@62:         return SyslogRule('default', formats={ 'default': '{msg}' })
terom@51: 
terom@51: # TODO: combine SyslogRule/Rules into one heirarchial SyslogRule -type?
terom@45: class SyslogRule (object) :
terom@45:     """
terom@55:         A named SyslogFilter with sub-rules.
terom@45:     """
terom@51: 
terom@55:     @classmethod
terom@55:     def load (cls, file) :
terom@55:         """
terom@55:             Load SyslogRule from file.
terom@55:         """
terom@45: 
terom@55:         config = configobj.ConfigObj(file)
terom@66: 
terom@66:         return cls.config_section(file.name, config)
terom@66:     
terom@66:     @classmethod
terom@66:     def config_section (cls, name, section) :
terom@66:         """
terom@66:             Recursively load Syslogrules from config section.
terom@66:         """
terom@66: 
terom@66:         rules = [cls.config_section(subsection, section[subsection]) for subsection in section.sections]
terom@66:         attrs = dict((name, section[name]) for name in section.scalars)
terom@66:          
terom@66:         return cls.config(name, rules=rules, **attrs)
terom@45: 
terom@55:     @classmethod
terom@58:     def config (cls, name, format=None, program=None, pattern=None, rules=None, **filters) :
terom@55:         """
terom@55:             Build SyslogRule from config options
terom@55:         """
terom@55: 
terom@55:         if pattern :
terom@55:             pattern = re.compile(pattern)
terom@55: 
terom@58:         if format :
terom@58:             format = { name: format }
terom@55: 
terom@55:         filters = dict(
terom@58:             (attr, re.compile(regex)) for attr, regex in filters.iteritems()
terom@55:         )
terom@55: 
terom@58:         if program :
terom@58:             filters['prog'] = program
terom@55: 
terom@58:         if pattern :
terom@58:             filters['msg'] = pattern
terom@55: 
terom@58:         filter = SyslogFilter(**filters)
terom@66:         
terom@66:         log.debug("%s: %s %s", name, rules, filter)
terom@58: 
terom@58:         return cls(name, rules, filter, format)
terom@58: 
terom@66:     def __init__ (self, name, rules=None, filter=None, formats=None) : 
terom@55:         self.name = name
terom@55:         self.rules = rules or [] # sub-rules
terom@55:         self.filter = filter # SyslogFilter
terom@66:         self.formats = formats or {}
terom@55: 
terom@55:     def match (self, item) :
terom@55:         """
terom@55:             Match item against our filter, applying any matches.
terom@55:         """
terom@55:         
terom@55:         if self.filter :
terom@55:             # filter
terom@55:             matches = self.filter.filter(item)
terom@55: 
terom@55:         else :
terom@55:             # match all
terom@55:             matches = True
terom@55: 
terom@58:         log.debug("%s: %s", self, matches)
terom@58: 
terom@58:         if not matches :
terom@58:             # ignore
terom@58:             return None
terom@58: 
terom@55:         # apply
terom@55:         item['rule'] = self
terom@55: 
terom@55:         if matches is True :
terom@55:             # no-op filter
terom@55:             pass
terom@55:         else :
terom@55:             item.update(matches)
terom@55:         
terom@55:         # XXX: copy, not mutate?
terom@55:         return item
terom@58: 
terom@58:     def format (self, item) :
terom@58:         """
terom@58:             Apply output formats
terom@58:         """
terom@66: 
terom@66:         out = {}
terom@58:         
terom@58:         for attr, format in self.formats.iteritems() :
terom@66:             value = out[attr] = format.format(**item)
terom@58:             log.debug("%s: %s: %s", self, attr, value)
terom@58:         
terom@66:         return out
terom@58: 
terom@55:     # TODO: __call__?
terom@45:     def apply (self, item) :
terom@45:         """
terom@66:             Match item against ourself, apply against any sub-rules, and return output, if hit.
terom@45:         """
terom@45: 
terom@55:         item = self.match(item)
terom@45: 
terom@55:         if not item :
terom@66:             # skip
terom@55:             return
terom@55: 
terom@55:         # sub-rules
terom@55:         for rule in self.rules :
terom@55:             try :
terom@66:                 out = rule.apply(item)
terom@55: 
terom@55:             except Exception as ex :
terom@55:                 log.exception("rule %s: %r", rule, item)
terom@55:                 return # XXX: skip?
terom@55: 
terom@66:             if out :
terom@66:                 # hit
terom@66:                 return out
terom@45:             
terom@55:         # TODO: routing/formatting
terom@58:         #if self.tag is False :
terom@58:         #    # drop
terom@58:         #    return False
terom@58:     
terom@58:         if self.formats :
terom@66:             # hit
terom@66:             item.update(self.format(item))
terom@66:         
terom@55:         return item
terom@51: 
terom@55:     def __iter__ (self, items) :
terom@47:         """
terom@47:             Apply items against our rules, yielding any matches.
terom@47:         """
terom@47: 
terom@47:         for item in items :
terom@47:             match = self.apply(item)
terom@47: 
terom@47:             if match :
terom@47:                 yield match
terom@55:  
terom@55:     def __str__ (self) :
terom@55:         return self.name
terom@55:     
terom@55:     def __repr__ (self) :
terom@55:         return 'SyslogRule({self.name}, ...)'.format(self=self)
terom@55: