#!/usr/bin/python # Frr Reloader # Copyright (C) 2014 Cumulus Networks, Inc. # # This file is part of Frr. # # Frr is free software; you can redistribute it and/or modify it # under the terms of the GNU General Public License as published by the # Free Software Foundation; either version 2, or (at your option) any # later version. # # Frr is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # General Public License for more details. # # You should have received a copy of the GNU General Public License # along with Frr; see the file COPYING. If not, write to the Free # Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA # 02111-1307, USA. # """ This program - reads a frr configuration text file - reads frr's current running configuration via "vtysh -c 'show running'" - compares the two configs and determines what commands to execute to synchronize frr's running configuration with the configuation in the text file """ import argparse import copy import logging import os import random import re import string import subprocess import sys from collections import OrderedDict from ipaddr import IPv6Address, IPNetwork from pprint import pformat log = logging.getLogger(__name__) class VtyshMarkException(Exception): pass class Context(object): """ A Context object represents a section of frr configuration such as: ! interface swp3 description swp3 -> r8's swp1 ipv6 nd suppress-ra link-detect ! or a single line context object such as this: ip forwarding """ def __init__(self, keys, lines): self.keys = keys self.lines = lines # Keep a dictionary of the lines, this is to make it easy to tell if a # line exists in this Context self.dlines = OrderedDict() for ligne in lines: self.dlines[ligne] = True def add_lines(self, lines): """ Add lines to specified context """ self.lines.extend(lines) for ligne in lines: self.dlines[ligne] = True class Config(object): """ A frr configuration is stored in a Config object. A Config object contains a dictionary of Context objects where the Context keys ('router ospf' for example) are our dictionary key. """ def __init__(self): self.lines = [] self.contexts = OrderedDict() def load_from_file(self, filename): """ Read configuration from specified file and slurp it into internal memory The internal representation has been marked appropriately by passing it through vtysh with the -m parameter """ log.info('Loading Config object from file %s', filename) try: file_output = subprocess.check_output(['/usr/bin/vtysh', '-m', '-f', filename], stderr=subprocess.STDOUT) except subprocess.CalledProcessError as e: ve = VtyshMarkException(e) ve.output = e.output raise ve for line in file_output.split('\n'): line = line.strip() if ":" in line: qv6_line = get_normalized_ipv6_line(line) self.lines.append(qv6_line) else: self.lines.append(line) self.load_contexts() def load_from_show_running(self): """ Read running configuration and slurp it into internal memory The internal representation has been marked appropriately by passing it through vtysh with the -m parameter """ log.info('Loading Config object from vtysh show running') try: config_text = subprocess.check_output( "/usr/bin/vtysh -c 'show run' | /usr/bin/tail -n +4 | /usr/bin/vtysh -m -f -", shell=True, stderr=subprocess.STDOUT) except subprocess.CalledProcessError as e: ve = VtyshMarkException(e) ve.output = e.output raise ve for line in config_text.split('\n'): line = line.strip() if (line == 'Building configuration...' or line == 'Current configuration:' or not line): continue self.lines.append(line) self.load_contexts() def get_lines(self): """ Return the lines read in from the configuration """ return '\n'.join(self.lines) def get_contexts(self): """ Return the parsed context as strings for display, log etc. """ for (_, ctx) in sorted(self.contexts.iteritems()): print str(ctx) + '\n' def save_contexts(self, key, lines): """ Save the provided key and lines as a context """ if not key: return ''' IP addresses specified in "network" statements, "ip prefix-lists" etc. can differ in the host part of the specification the user provides and what the running config displays. For example, user can specify 11.1.1.1/24, and the running config displays this as 11.1.1.0/24. Ensure we don't do a needless operation for such lines. IS-IS & OSPFv3 have no "network" support. ''' re_key_rt = re.match(r'(ip|ipv6)\s+route\s+([A-Fa-f:.0-9/]+)(.*)$', key[0]) if re_key_rt: addr = re_key_rt.group(2) if '/' in addr: try: newaddr = IPNetwork(addr) key[0] = '%s route %s/%s%s' % (re_key_rt.group(1), newaddr.network, newaddr.prefixlen, re_key_rt.group(3)) except ValueError: pass re_key_rt = re.match( r'(ip|ipv6)\s+prefix-list(.*)(permit|deny)\s+([A-Fa-f:.0-9/]+)(.*)$', key[0] ) if re_key_rt: addr = re_key_rt.group(4) if '/' in addr: try: newaddr = '%s/%s' % (IPNetwork(addr).network, IPNetwork(addr).prefixlen) except ValueError: newaddr = addr else: newaddr = addr legestr = re_key_rt.group(5) re_lege = re.search(r'(.*)le\s+(\d+)\s+ge\s+(\d+)(.*)', legestr) if re_lege: legestr = '%sge %s le %s%s' % (re_lege.group(1), re_lege.group(3), re_lege.group(2), re_lege.group(4)) re_lege = re.search(r'(.*)ge\s+(\d+)\s+le\s+(\d+)(.*)', legestr) if (re_lege and ((re_key_rt.group(1) == "ip" and re_lege.group(3) == "32") or (re_key_rt.group(1) == "ipv6" and re_lege.group(3) == "128"))): legestr = '%sge %s%s' % (re_lege.group(1), re_lege.group(2), re_lege.group(4)) key[0] = '%s prefix-list%s%s %s%s' % (re_key_rt.group(1), re_key_rt.group(2), re_key_rt.group(3), newaddr, legestr) if lines and key[0].startswith('router bgp'): newlines = [] for line in lines: re_net = re.match(r'network\s+([A-Fa-f:.0-9/]+)(.*)$', line) if re_net: addr = re_net.group(1) if '/' not in addr and key[0].startswith('router bgp'): # This is most likely an error because with no # prefixlen, BGP treats the prefixlen as 8 addr = addr + '/8' try: newaddr = IPNetwork(addr) line = 'network %s/%s %s' % (newaddr.network, newaddr.prefixlen, re_net.group(2)) newlines.append(line) except ValueError: # Really this should be an error. Whats a network # without an IP Address following it ? newlines.append(line) else: newlines.append(line) lines = newlines ''' More fixups in user specification and what running config shows. "null0" in routes must be replaced by Null0, and "blackhole" must be replaced by Null0 as well. ''' if (key[0].startswith('ip route') or key[0].startswith('ipv6 route') and 'null0' in key[0] or 'blackhole' in key[0]): key[0] = re.sub(r'\s+null0(\s*$)', ' Null0', key[0]) key[0] = re.sub(r'\s+blackhole(\s*$)', ' Null0', key[0]) if lines: if tuple(key) not in self.contexts: ctx = Context(tuple(key), lines) self.contexts[tuple(key)] = ctx else: ctx = self.contexts[tuple(key)] ctx.add_lines(lines) else: if tuple(key) not in self.contexts: ctx = Context(tuple(key), []) self.contexts[tuple(key)] = ctx def load_contexts(self): """ Parse the configuration and create contexts for each appropriate block """ current_context_lines = [] ctx_keys = [] ''' The end of a context is flagged via the 'end' keyword: ! interface swp52 ipv6 nd suppress-ra link-detect ! end router bgp 10 bgp router-id 10.0.0.1 bgp log-neighbor-changes no bgp default ipv4-unicast neighbor EBGP peer-group neighbor EBGP advertisement-interval 1 neighbor EBGP timers connect 10 neighbor 2001:40:1:4::6 remote-as 40 neighbor 2001:40:1:8::a remote-as 40 ! end address-family ipv6 neighbor IBGPv6 activate neighbor 2001:10::2 peer-group IBGPv6 neighbor 2001:10::3 peer-group IBGPv6 exit-address-family ! end router ospf ospf router-id 10.0.0.1 log-adjacency-changes detail timers throttle spf 0 50 5000 ! end ''' # The code assumes that its working on the output from the "vtysh -m" # command. That provides the appropriate markers to signify end of # a context. This routine uses that to build the contexts for the # config. # # There are single line contexts such as "log file /media/node/zebra.log" # and multi-line contexts such as "router ospf" and subcontexts # within a context such as "address-family" within "router bgp" # In each of these cases, the first line of the context becomes the # key of the context. So "router bgp 10" is the key for the non-address # family part of bgp, "router bgp 10, address-family ipv6 unicast" is # the key for the subcontext and so on. ctx_keys = [] main_ctx_key = [] new_ctx = True # the keywords that we know are single line contexts. bgp in this case # is not the main router bgp block, but enabling multi-instance oneline_ctx_keywords = ("access-list ", "agentx", "bgp ", "debug ", "dump ", "enable ", "frr ", "hostname ", "ip ", "ipv6 ", "log ", "mpls", "no ", "password ", "ptm-enable", "router-id ", "service ", "table ", "username ", "zebra ") for line in self.lines: if not line: continue if line.startswith('!') or line.startswith('#'): continue # one line contexts if new_ctx is True and any(line.startswith(keyword) for keyword in oneline_ctx_keywords): self.save_contexts(ctx_keys, current_context_lines) # Start a new context main_ctx_key = [] ctx_keys = [line, ] current_context_lines = [] log.debug('LINE %-50s: entering new context, %-50s', line, ctx_keys) self.save_contexts(ctx_keys, current_context_lines) new_ctx = True elif line == "end": self.save_contexts(ctx_keys, current_context_lines) log.debug('LINE %-50s: exiting old context, %-50s', line, ctx_keys) # Start a new context new_ctx = True main_ctx_key = [] ctx_keys = [] current_context_lines = [] elif line == "exit-address-family" or line == "exit": # if this exit is for address-family ipv4 unicast, ignore the pop if main_ctx_key: self.save_contexts(ctx_keys, current_context_lines) # Start a new context ctx_keys = copy.deepcopy(main_ctx_key) current_context_lines = [] log.debug('LINE %-50s: popping from subcontext to ctx%-50s', line, ctx_keys) elif new_ctx is True: if not main_ctx_key: ctx_keys = [line, ] else: ctx_keys = copy.deepcopy(main_ctx_key) main_ctx_key = [] current_context_lines = [] new_ctx = False log.debug('LINE %-50s: entering new context, %-50s', line, ctx_keys) elif "address-family " in line: main_ctx_key = [] # Save old context first self.save_contexts(ctx_keys, current_context_lines) current_context_lines = [] main_ctx_key = copy.deepcopy(ctx_keys) log.debug('LINE %-50s: entering sub-context, append to ctx_keys', line) if line == "address-family ipv6": ctx_keys.append("address-family ipv6 unicast") elif line == "address-family ipv4": ctx_keys.append("address-family ipv4 unicast") else: ctx_keys.append(line) else: # Continuing in an existing context, add non-commented lines to it current_context_lines.append(line) log.debug('LINE %-50s: append to current_context_lines, %-50s', line, ctx_keys) # Save the context of the last one self.save_contexts(ctx_keys, current_context_lines) def line_to_vtysh_conft(ctx_keys, line, delete): """ Return the vtysh command for the specified context line """ cmd = [] cmd.append('vtysh') cmd.append('-c') cmd.append('conf t') if line: for ctx_key in ctx_keys: cmd.append('-c') cmd.append(ctx_key) line = line.lstrip() if delete: cmd.append('-c') if line.startswith('no '): cmd.append('%s' % line[3:]) else: cmd.append('no %s' % line) else: cmd.append('-c') cmd.append(line) # If line is None then we are typically deleting an entire # context ('no router ospf' for example) else: if delete: # Only put the 'no' on the last sub-context for ctx_key in ctx_keys: cmd.append('-c') if ctx_key == ctx_keys[-1]: cmd.append('no %s' % ctx_key) else: cmd.append('%s' % ctx_key) else: for ctx_key in ctx_keys: cmd.append('-c') cmd.append(ctx_key) return cmd def line_for_vtysh_file(ctx_keys, line, delete): """ Return the command as it would appear in frr.conf """ cmd = [] if line: for (i, ctx_key) in enumerate(ctx_keys): cmd.append(' ' * i + ctx_key) line = line.lstrip() indent = len(ctx_keys) * ' ' if delete: if line.startswith('no '): cmd.append('%s%s' % (indent, line[3:])) else: cmd.append('%sno %s' % (indent, line)) else: cmd.append(indent + line) # If line is None then we are typically deleting an entire # context ('no router ospf' for example) else: if delete: # Only put the 'no' on the last sub-context for ctx_key in ctx_keys: if ctx_key == ctx_keys[-1]: cmd.append('no %s' % ctx_key) else: cmd.append('%s' % ctx_key) else: for ctx_key in ctx_keys: cmd.append(ctx_key) return '\n' + '\n'.join(cmd) def get_normalized_ipv6_line(line): """ Return a normalized IPv6 line as produced by frr, with all letters in lower case and trailing and leading zeros removed, and only the network portion present if the IPv6 word is a network """ norm_line = "" words = line.split(' ') for word in words: if ":" in word: norm_word = None if "/" in word: try: v6word = IPNetwork(word) norm_word = '%s/%s' % (v6word.network, v6word.prefixlen) except ValueError: pass if not norm_word: try: norm_word = '%s' % IPv6Address(word) except ValueError: norm_word = word else: norm_word = word norm_line = norm_line + " " + norm_word return norm_line.strip() def line_exist(lines, target_ctx_keys, target_line): for (ctx_keys, line) in lines: if ctx_keys == target_ctx_keys and line == target_line: return True return False def ignore_delete_re_add_lines(lines_to_add, lines_to_del): # Quite possibly the most confusing (while accurate) variable names in history lines_to_add_to_del = [] lines_to_del_to_del = [] for (ctx_keys, line) in lines_to_del: deleted = False if ctx_keys[0].startswith('router bgp') and line and line.startswith('neighbor '): """ BGP changed how it displays swpX peers that are part of peer-group. Older versions of frr would display these on separate lines: neighbor swp1 interface neighbor swp1 peer-group FOO but today we display via a single line neighbor swp1 interface peer-group FOO This change confuses frr-reload.py so check to see if we are deleting neighbor swp1 interface peer-group FOO and adding neighbor swp1 interface neighbor swp1 peer-group FOO If so then chop the del line and the corresponding add lines """ re_swpx_int_peergroup = re.search('neighbor (\S+) interface peer-group (\S+)', line) re_swpx_int_v6only_peergroup = re.search('neighbor (\S+) interface v6only peer-group (\S+)', line) if re_swpx_int_peergroup or re_swpx_int_v6only_peergroup: swpx_interface = None swpx_peergroup = None if re_swpx_int_peergroup: swpx = re_swpx_int_peergroup.group(1) peergroup = re_swpx_int_peergroup.group(2) swpx_interface = "neighbor %s interface" % swpx elif re_swpx_int_v6only_peergroup: swpx = re_swpx_int_v6only_peergroup.group(1) peergroup = re_swpx_int_v6only_peergroup.group(2) swpx_interface = "neighbor %s interface v6only" % swpx swpx_peergroup = "neighbor %s peer-group %s" % (swpx, peergroup) found_add_swpx_interface = line_exist(lines_to_add, ctx_keys, swpx_interface) found_add_swpx_peergroup = line_exist(lines_to_add, ctx_keys, swpx_peergroup) tmp_ctx_keys = tuple(list(ctx_keys)) if not found_add_swpx_peergroup: tmp_ctx_keys = list(ctx_keys) tmp_ctx_keys.append('address-family ipv4 unicast') tmp_ctx_keys = tuple(tmp_ctx_keys) found_add_swpx_peergroup = line_exist(lines_to_add, tmp_ctx_keys, swpx_peergroup) if not found_add_swpx_peergroup: tmp_ctx_keys = list(ctx_keys) tmp_ctx_keys.append('address-family ipv6 unicast') tmp_ctx_keys = tuple(tmp_ctx_keys) found_add_swpx_peergroup = line_exist(lines_to_add, tmp_ctx_keys, swpx_peergroup) if found_add_swpx_interface and found_add_swpx_peergroup: deleted = True lines_to_del_to_del.append((ctx_keys, line)) lines_to_add_to_del.append((ctx_keys, swpx_interface)) lines_to_add_to_del.append((tmp_ctx_keys, swpx_peergroup)) """ In 3.0.1 we changed how we display neighbor interface command. Older versions of frr would display the following: neighbor swp1 interface neighbor swp1 remote-as external neighbor swp1 capability extended-nexthop but today we display via a single line neighbor swp1 interface remote-as external and capability extended-nexthop is no longer needed because we automatically enable it when the neighbor is of type interface. This change confuses frr-reload.py so check to see if we are deleting neighbor swp1 interface remote-as (external|internal|ASNUM) and adding neighbor swp1 interface neighbor swp1 remote-as (external|internal|ASNUM) neighbor swp1 capability extended-nexthop If so then chop the del line and the corresponding add lines """ re_swpx_int_remoteas = re.search('neighbor (\S+) interface remote-as (\S+)', line) re_swpx_int_v6only_remoteas = re.search('neighbor (\S+) interface v6only remote-as (\S+)', line) if re_swpx_int_remoteas or re_swpx_int_v6only_remoteas: swpx_interface = None swpx_remoteas = None if re_swpx_int_remoteas: swpx = re_swpx_int_remoteas.group(1) remoteas = re_swpx_int_remoteas.group(2) swpx_interface = "neighbor %s interface" % swpx elif re_swpx_int_v6only_remoteas: swpx = re_swpx_int_v6only_remoteas.group(1) remoteas = re_swpx_int_v6only_remoteas.group(2) swpx_interface = "neighbor %s interface v6only" % swpx swpx_remoteas = "neighbor %s remote-as %s" % (swpx, remoteas) found_add_swpx_interface = line_exist(lines_to_add, ctx_keys, swpx_interface) found_add_swpx_remoteas = line_exist(lines_to_add, ctx_keys, swpx_remoteas) tmp_ctx_keys = tuple(list(ctx_keys)) if found_add_swpx_interface and found_add_swpx_remoteas: deleted = True lines_to_del_to_del.append((ctx_keys, line)) lines_to_add_to_del.append((ctx_keys, swpx_interface)) lines_to_add_to_del.append((tmp_ctx_keys, swpx_remoteas)) ''' In 3.0, we made bgp bestpath multipath as-relax command automatically assume no-as-set since the lack of this option caused weird routing problems and this problem was peculiar to this implementation. When the running config is shown in relases after 3.0, the no-as-set is not shown as its the default. This causes reload to unnecessarily unapply this option to only apply it back again, causing unnecessary session resets. Handle this. ''' if ctx_keys[0].startswith('router bgp') and line and 'multipath-relax' in line: re_asrelax_new = re.search('^bgp\s+bestpath\s+as-path\s+multipath-relax$', line) old_asrelax_cmd = 'bgp bestpath as-path multipath-relax no-as-set' found_asrelax_old = line_exist(lines_to_add, ctx_keys, old_asrelax_cmd) if re_asrelax_new and found_asrelax_old: deleted = True lines_to_del_to_del.append((ctx_keys, line)) lines_to_add_to_del.append((ctx_keys, old_asrelax_cmd)) ''' More old-to-new config handling. ip import-table no longer accepts distance, but we honor the old syntax. But 'show running' shows only the new syntax. This causes an unnecessary 'no import-table' followed by the same old 'ip import-table' which causes perturbations in announced routes leading to traffic blackholes. Fix this issue. ''' re_importtbl = re.search('^ip\s+import-table\s+(\d+)$', ctx_keys[0]) if re_importtbl: table_num = re_importtbl.group(1) for ctx in lines_to_add: if ctx[0][0].startswith('ip import-table %s distance' % table_num): lines_to_del_to_del.append((('ip import-table %s' % table_num,), None)) lines_to_add_to_del.append((ctx[0], None)) ''' ip/ipv6 prefix-list can be specified without a seq number. However, the running config always adds 'seq x', where x is a number incremented by 5 for every element, to the prefix list. So, ignore such lines as well. Sample prefix-list lines: ip prefix-list PR-TABLE-2 seq 5 permit 20.8.2.0/24 le 32 ip prefix-list PR-TABLE-2 seq 10 permit 20.8.2.0/24 le 32 ipv6 prefix-list vrfdev6-12 permit 2000:9:2::/64 gt 64 ''' re_ip_pfxlst = re.search('^(ip|ipv6)(\s+prefix-list\s+)(\S+\s+)(seq \d+\s+)(permit|deny)(.*)$', ctx_keys[0]) if re_ip_pfxlst: tmpline = (re_ip_pfxlst.group(1) + re_ip_pfxlst.group(2) + re_ip_pfxlst.group(3) + re_ip_pfxlst.group(5) + re_ip_pfxlst.group(6)) for ctx in lines_to_add: if ctx[0][0] == tmpline: lines_to_del_to_del.append((ctx_keys, None)) lines_to_add_to_del.append(((tmpline,), None)) if not deleted: found_add_line = line_exist(lines_to_add, ctx_keys, line) if found_add_line: lines_to_del_to_del.append((ctx_keys, line)) lines_to_add_to_del.append((ctx_keys, line)) else: ''' We have commands that used to be displayed in the global part of 'router bgp' that are now displayed under 'address-family ipv4 unicast' # old way router bgp 64900 neighbor ISL advertisement-interval 0 vs. # new way router bgp 64900 address-family ipv4 unicast neighbor ISL advertisement-interval 0 Look to see if we are deleting it in one format just to add it back in the other ''' if ctx_keys[0].startswith('router bgp') and len(ctx_keys) > 1 and ctx_keys[1] == 'address-family ipv4 unicast': tmp_ctx_keys = list(ctx_keys)[:-1] tmp_ctx_keys = tuple(tmp_ctx_keys) found_add_line = line_exist(lines_to_add, tmp_ctx_keys, line) if found_add_line: lines_to_del_to_del.append((ctx_keys, line)) lines_to_add_to_del.append((tmp_ctx_keys, line)) for (ctx_keys, line) in lines_to_del_to_del: lines_to_del.remove((ctx_keys, line)) for (ctx_keys, line) in lines_to_add_to_del: lines_to_add.remove((ctx_keys, line)) return (lines_to_add, lines_to_del) def compare_context_objects(newconf, running): """ Create a context diff for the two specified contexts """ # Compare the two Config objects to find the lines that we need to add/del lines_to_add = [] lines_to_del = [] delete_bgpd = False # Find contexts that are in newconf but not in running # Find contexts that are in running but not in newconf for (running_ctx_keys, running_ctx) in running.contexts.iteritems(): if running_ctx_keys not in newconf.contexts: # We check that the len is 1 here so that we only look at ('router bgp 10') # and not ('router bgp 10', 'address-family ipv4 unicast'). The # latter could cause a false delete_bgpd positive if ipv4 unicast is in # running but not in newconf. if "router bgp" in running_ctx_keys[0] and len(running_ctx_keys) == 1: delete_bgpd = True lines_to_del.append((running_ctx_keys, None)) # We cannot do 'no interface' in quagga, and so deal with it elif running_ctx_keys[0].startswith('interface'): for line in running_ctx.lines: lines_to_del.append((running_ctx_keys, line)) # If this is an address-family under 'router bgp' and we are already deleting the # entire 'router bgp' context then ignore this sub-context elif "router bgp" in running_ctx_keys[0] and len(running_ctx_keys) > 1 and delete_bgpd: continue elif ("router bgp" in running_ctx_keys[0] and len(running_ctx_keys) > 1 and running_ctx_keys[1].startswith('address-family')): # There's no 'no address-family' support and so we have to # delete each line individually again for line in running_ctx.lines: lines_to_del.append((running_ctx_keys, line)) # Non-global context elif running_ctx_keys and not any("address-family" in key for key in running_ctx_keys): lines_to_del.append((running_ctx_keys, None)) # Global context else: for line in running_ctx.lines: lines_to_del.append((running_ctx_keys, line)) # Find the lines within each context to add # Find the lines within each context to del for (newconf_ctx_keys, newconf_ctx) in newconf.contexts.iteritems(): if newconf_ctx_keys in running.contexts: running_ctx = running.contexts[newconf_ctx_keys] for line in newconf_ctx.lines: if line not in running_ctx.dlines: lines_to_add.append((newconf_ctx_keys, line)) for line in running_ctx.lines: if line not in newconf_ctx.dlines: lines_to_del.append((newconf_ctx_keys, line)) for (newconf_ctx_keys, newconf_ctx) in newconf.contexts.iteritems(): if newconf_ctx_keys not in running.contexts: lines_to_add.append((newconf_ctx_keys, None)) for line in newconf_ctx.lines: lines_to_add.append((newconf_ctx_keys, line)) (lines_to_add, lines_to_del) = ignore_delete_re_add_lines(lines_to_add, lines_to_del) return (lines_to_add, lines_to_del) if __name__ == '__main__': # Command line options parser = argparse.ArgumentParser(description='Dynamically apply diff in frr configs') parser.add_argument('--input', help='Read running config from file instead of "show running"') group = parser.add_mutually_exclusive_group(required=True) group.add_argument('--reload', action='store_true', help='Apply the deltas', default=False) group.add_argument('--test', action='store_true', help='Show the deltas', default=False) parser.add_argument('--debug', action='store_true', help='Enable debugs', default=False) parser.add_argument('--stdout', action='store_true', help='Log to STDOUT', default=False) parser.add_argument('filename', help='Location of new frr config file') parser.add_argument('--overwrite', action='store_true', help='Overwrite frr.conf with running config output', default=False) args = parser.parse_args() # Logging # For --test log to stdout # For --reload log to /var/log/frr/frr-reload.log if args.test or args.stdout: logging.basicConfig(level=logging.INFO, format='%(asctime)s %(levelname)5s: %(message)s') # Color the errors and warnings in red logging.addLevelName(logging.ERROR, "\033[91m %s\033[0m" % logging.getLevelName(logging.ERROR)) logging.addLevelName(logging.WARNING, "\033[91m%s\033[0m" % logging.getLevelName(logging.WARNING)) elif args.reload: if not os.path.isdir('/var/log/frr/'): os.makedirs('/var/log/frr/') logging.basicConfig(filename='/var/log/frr/frr-reload.log', level=logging.INFO, format='%(asctime)s %(levelname)5s: %(message)s') # argparse should prevent this from happening but just to be safe... else: raise Exception('Must specify --reload or --test') log = logging.getLogger(__name__) # Verify the new config file is valid if not os.path.isfile(args.filename): msg = "Filename %s does not exist" % args.filename print msg log.error(msg) sys.exit(1) if not os.path.getsize(args.filename): msg = "Filename %s is an empty file" % args.filename print msg log.error(msg) sys.exit(1) # Verify that 'service integrated-vtysh-config' is configured vtysh_filename = '/etc/frr/vtysh.conf' service_integrated_vtysh_config = True if os.path.isfile(vtysh_filename): with open(vtysh_filename, 'r') as fh: for line in fh.readlines(): line = line.strip() if line == 'no service integrated-vtysh-config': service_integrated_vtysh_config = False break if not service_integrated_vtysh_config: msg = "'service integrated-vtysh-config' is not configured, this is required for 'service frr reload'" print msg log.error(msg) sys.exit(1) if args.debug: log.setLevel(logging.DEBUG) log.info('Called via "%s"', str(args)) # Create a Config object from the config generated by newconf newconf = Config() newconf.load_from_file(args.filename) reload_ok = True if args.test: # Create a Config object from the running config running = Config() if args.input: running.load_from_file(args.input) else: running.load_from_show_running() (lines_to_add, lines_to_del) = compare_context_objects(newconf, running) lines_to_configure = [] if lines_to_del: print "\nLines To Delete" print "===============" for (ctx_keys, line) in lines_to_del: if line == '!': continue cmd = line_for_vtysh_file(ctx_keys, line, True) lines_to_configure.append(cmd) print cmd if lines_to_add: print "\nLines To Add" print "============" for (ctx_keys, line) in lines_to_add: if line == '!': continue cmd = line_for_vtysh_file(ctx_keys, line, False) lines_to_configure.append(cmd) print cmd elif args.reload: log.debug('New Frr Config\n%s', newconf.get_lines()) # This looks a little odd but we have to do this twice...here is why # If the user had this running bgp config: # # router bgp 10 # neighbor 1.1.1.1 remote-as 50 # neighbor 1.1.1.1 route-map FOO out # # and this config in the newconf config file # # router bgp 10 # neighbor 1.1.1.1 remote-as 999 # neighbor 1.1.1.1 route-map FOO out # # # Then the script will do # - no neighbor 1.1.1.1 remote-as 50 # - neighbor 1.1.1.1 remote-as 999 # # The problem is the "no neighbor 1.1.1.1 remote-as 50" will also remove # the "neighbor 1.1.1.1 route-map FOO out" line...so we compare the # configs again to put this line back. # There are many keywords in quagga that can only appear one time under # a context, take "bgp router-id" for example. If the config that we are # reloading against has the following: # # router bgp 10 # bgp router-id 1.1.1.1 # bgp router-id 2.2.2.2 # # The final config needs to contain "bgp router-id 2.2.2.2". On the # first pass we will add "bgp router-id 2.2.2.2" but then on the second # pass we will see that "bgp router-id 1.1.1.1" is missing and add that # back which cancels out the "bgp router-id 2.2.2.2". The fix is for the # second pass to include all of the "adds" from the first pass. lines_to_add_first_pass = [] for x in range(2): running = Config() running.load_from_show_running() log.debug('Running Frr Config (Pass #%d)\n%s', x, running.get_lines()) (lines_to_add, lines_to_del) = compare_context_objects(newconf, running) if x == 0: lines_to_add_first_pass = lines_to_add else: lines_to_add.extend(lines_to_add_first_pass) # Only do deletes on the first pass. The reason being if we # configure a bgp neighbor via "neighbor swp1 interface" quagga # will automatically add: # # interface swp1 # ipv6 nd ra-interval 10 # no ipv6 nd suppress-ra # ! # # but those lines aren't in the config we are reloading against so # on the 2nd pass they will show up in lines_to_del. This could # apply to other scenarios as well where configuring FOO adds BAR # to the config. if lines_to_del and x == 0: for (ctx_keys, line) in lines_to_del: if line == '!': continue # 'no' commands are tricky, we can't just put them in a file and # vtysh -f that file. See the next comment for an explanation # of their quirks cmd = line_to_vtysh_conft(ctx_keys, line, True) original_cmd = cmd # Some commands in frr are picky about taking a "no" of the entire line. # OSPF is bad about this, you can't "no" the entire line, you have to "no" # only the beginning. If we hit one of these command an exception will be # thrown. Catch it and remove the last '-c', 'FOO' from cmd and try again. # # Example: # frr(config-if)# ip ospf authentication message-digest 1.1.1.1 # frr(config-if)# no ip ospf authentication message-digest 1.1.1.1 # % Unknown command. # frr(config-if)# no ip ospf authentication message-digest # % Unknown command. # frr(config-if)# no ip ospf authentication # frr(config-if)# while True: try: _ = subprocess.check_output(cmd) except subprocess.CalledProcessError: # - Pull the last entry from cmd (this would be # 'no ip ospf authentication message-digest 1.1.1.1' in # our example above # - Split that last entry by whitespace and drop the last word log.info('Failed to execute %s', ' '.join(cmd)) last_arg = cmd[-1].split(' ') if len(last_arg) <= 2: log.error('"%s" we failed to remove this command', original_cmd) break new_last_arg = last_arg[0:-1] cmd[-1] = ' '.join(new_last_arg) else: log.info('Executed "%s"', ' '.join(cmd)) break if lines_to_add: lines_to_configure = [] for (ctx_keys, line) in lines_to_add: if line == '!': continue cmd = line_for_vtysh_file(ctx_keys, line, False) lines_to_configure.append(cmd) if lines_to_configure: random_string = ''.join(random.SystemRandom().choice( string.ascii_uppercase + string.digits) for _ in range(6)) filename = "/var/run/frr/reload-%s.txt" % random_string log.info("%s content\n%s" % (filename, pformat(lines_to_configure))) with open(filename, 'w') as fh: for line in lines_to_configure: fh.write(line + '\n') output = subprocess.check_output(['/usr/bin/vtysh', '-f', filename]) # exit non-zero if we see these errors for x in ('BGP instance name and AS number mismatch', 'BGP instance is already running', '% not a local address'): for line in output.splitlines(): if x in line: msg = "ERROR: %s" % x log.error(msg) print msg reload_ok = False os.unlink(filename) # Make these changes persistent if args.overwrite or args.filename != '/etc/frr/frr.conf': subprocess.call(['/usr/bin/vtysh', '-c', 'write']) if not reload_ok: sys.exit(1)