kstaniek / ciscoconfparse Goto Github PK

INTRO
ciscoconfparse is a Python package for parsing through Cisco IOS-style 
configurations and retrieving portions of the config based on a variety of 
query methods.

The package will process an IOS-style config and break it into a set of 
linked parent / child relationships. Then you issue queries against these 
relationships using a familiar family syntax model. Queries can either be in 
the form of a simple string, or you can use regular expressions. The API 
provides powerful query tools, including the ability to find all parents that 
have or do not have children matching a certain criteria. This means it is 
easy to find the interface names of all layer2 trunks in a Catalyst 6500, or 
retrieve a list of all interfaces with cdp disabled. Until this package, I 
know of no simple config-parsing APIs to do the same; it has traditionally 
been considered the domain of screen-scraping. In conjunction with python's 
sophisticated set-manipulation capabilities, your imagination is the limit.

The package also provides a set of methods to query and manipulate the 
IOSConfigLine objects themselves. This gives you a flexible mechanism to build 
your own custom queries, because the IOSConfigLine objects store all the 
parent / child hierarchy in them.

Examples of config family relationships are shown below...

Line01:policy-map QOS_1
Line02: class GOLD
Line03:  priority percent 10
Line04: class SILVER
Line05:  bandwidth 30
Line06:  random-detect
Line07: class default
Line08:!
Line09:interface Serial 1/0
Line10: encapsulation ppp
Line11: ip address 1.1.1.1 255.255.255.252
Line12:!
Line13:access-list 101 deny tcp any any eq 25 log
Line14:access-list 101 permit ip any any
 
parents: 01, 02, 04, 09
children: of 01 = 02, 04, 07
of 02 = 03
of 04 = 05, 06
of 09 = 10, 11
siblings: 02, 04, 07
05, 06
10, 11
oldest_ancestors: 01, 09
families: 01, 02, 03, 04, 05, 06, 07
09, 10, 11
family_endpoints: 07, 11


Note that 01, 09, 13 and 14 are not considered siblings, nor are they part of 
the same family. In fact, 13 and 14 do not belong to a family at all; they 
have no children.

The package provides several types of methods:

1. Query methods returning a list of text lines.
1.1 find_lines( self, linespec, exactmatch=False, ignore_ws=False ):
1.2 find_children( self, linespec, exactmatch=False, ignore_ws=False ):
1.3 find_all_children( self, linespec, exactmatch=False, ignore_ws=False ):
1.4 find_blocks( self, blockspec, exactmatch=False, ignore_ws=False ):
1.5 find_parents_w_child( self, parentspec, childspec, ignore_ws=False ):
1.6 find_parents_wo_child( self, parentspec, childspec, ignore_ws=False ):
1.7 req_cfgspec_all_diff( self, cfgspec ):
1.8 req_cfgspec_excl_diff( self, linespec, uncfgspec, cfgspec ):



2. Query methods returning a list of IOSConfigLine objects.
2.1 find_line_OBJ( self, linespec ):
2.2 find_sibling_OBJ( self, lineobject ):
2.3 find_child_OBJ( self, lineobject):
2.4 find_all_child_OBJ( self, lineobject ):
2.5 find_parent_OBJ( self, lineobject ):

3. Methods for manipulating IOSConfigLine objects
3.1 unique_OBJ( self, objectlist ):
3.2 objects_to_lines( self, objectlist ):
3.3 objects_to_uncfg( self, objectlist, unconflist ):

4. Query methods on IOSConfigLine objects
4.1 parent(self):
4.2 children(self):
4.3 has_children(self):
4.4 child_indent(self):
4.5 oldest_ancestor(self):
4.6 family_endpoint(self):
4.7 linenum(self):
4.8 text(self):
4.9 uncfgtext(self):


5. Methods for parsing the configuration: I won't bother explaining here...
You have the source if you are interested :-).


BASIC USAGE

#!/usr/bin/env python
from ciscoconfparse import *
 
parse = CiscoConfParse("/tftpboot/bucksnort.conf")
 
# Return a list of all ATM interfaces and subinterfaces
#
atm_intfs = parse.find_lines("^interface\sATM")
 
# Return a list of all interfaces with a certain QOS policy
#
qos_intfs = parse.find_parents_w_child( "^interf", "service-policy QOS_01" )
 
# Return a list of all active interfaces (i.e. not shutdown)
#
active_intfs = parse.find_parents_wo_child( "^interf", "shutdown" )
 
# Find all interfaces that have voice configured, if they are trusting dscp
# build a new config to trust cos
#
#  You must put a caret (^) sign in front of "interface" below... otherwise you will get matches
#  for any command with interface in the syntax.  ^ is a regular expression to match the beginning
#  of a line.
#
newcfg = []
voice_intfs = parse.find_parents_w_child("^interface", "switchport voice")
for intf in voice_intfs:
   famobj = CiscoConfParse( parse.find_children( intf, exactmatch = True ) )
   if( famobj.find_lines("mls qos trust dscp") ):
      newcfg.append(intf)
      newcfg.append(" mls qos trust cos")


The examples/ directory in the distribution contains more usage cases, 
including sample configs to parse. When enforcing configuration standards, the 
req_cfgspec_excl_diff() method is very useful; examples of its usage are 
included.



FAQ
Q1: Is there a way to use this module with perl?
A1: Yes, I do this myself. Install the python package as you normally would 
and import it into perl with Inline.pm and Inline::Python from CPAN.

Q2: When I use find_children("interface GigabitEthernet3/2"), I'm getting all 
interfaces beginning with 3/2, including 3/21, 3/22, 3/23 and 3/24. How can I 
limit my results?
A2. There are two ways... the simplest is to use the 'exactmatch' option... 
find_children("interface GigabitEthernet3/2", True). Another way is to utilize 
regex expansion that is native to many methods... 
find_children("interface GigabitEthernet3/2$")

AUTHOR
David Michael Pennington


THANKS
Thanks to David Muir Sharnoff for his suggestion about making a special case 
for IOS banners. Thanks to Alan Cownie for his API suggestions. Thanks to 
everyone in advance for their bug reports and patience. Sola Dei Gloria.