automonty/automonty

#!/usr/bin/python3

import argparse
import librouteros
import progress.bar
import ssl
import os
import yaml
import re
import dns.resolver, dns.reversename

# comment format:
# hostname.example.com [aM flag1 flag2 key1=value1 key2=option3:value3,option4:value4] selector.example.com
#
# flags:
#   static - do not auto-enable or auto-disable this address (loopbacks, linknets)
#   home - this is the normal home-location of the IP
#   evacuated - this has been moved from this host to elsewhere
#   evacuee - this is an evacuated address

aM1 = re.compile( r"\[aM ?([^]]*)\]" )
def parse_comment( comment ):
    bits = aM1.split( comment )
    if len( bits ) == 3:
        hostname = bits[ 0 ].strip()
        selector = bits[ 2 ].strip()
        if not selector:
            selector = hostname
        rval = {}
        for bit in bits[ 1 ].split():
            try:
                ( k, v ) = bit.split( "=", 1 )
            except ValueError:
                if bit:
                    rval[ bit ] = True
            else:
                if ':' in v:
                    rval[ k ] = {}
                    for subbit in v.split( "," ):
                        ( subk, subv ) = subbit.split( ":", 1 )
                        rval[ k ][ subk ] = subv
                else:
                    rval[ k ] = v
        return ( selector, rval, hostname )
    else:
        return ( None, None, comment )

def reverse_dns( address ):
    try:
        return str( dns.resolver.resolve( dns.reversename.from_address( address ), 'PTR' )[ 0 ] )
    except:
        return address

def make_comment( selector, rval, hostname ):
    rvalbits = [ "aM" ]
    for ( k, v ) in rval.items():
        if v is True:
            rvalbits.append( k )
        elif isinstance( v, dict ):
            rvalbits.append( "%s=%s" % ( k, ",".join( "%s:%s" % vi for vi in v.items() ) ) )
        else:
            rvalbits.append( "%s=%s" % ( k, v ) )
    if selector == hostname:
        return "%s [%s]" % ( hostname, " ".join( rvalbits ) )
    else:
        return "%s [%s] %s" % ( hostname, " ".join( rvalbits ), selector )

def connection( host, username = None, password = None, port = 8729 ):
    if ':' in host:
        ( host, port ) = host.split( ":", 1 )
        port = int( port )
    kwargs = { 'username': username or os.environ.get( 'AUTOMONTY_USERNAME', None ),
               'password': password or os.environ.get( 'AUTOMONTY_PASSWORD', None ),
               'host': host,
               'port': port,
               }
    kwargs[ 'ssl' ] = True
    ssl_ctx = ssl.create_default_context()
    ssl_ctx.check_hostname = False # XXX figure out how
    ssl_option = 'CERT_REQUIRED'
    ssl_ctx.verify_mode = getattr( ssl, ssl_option, ssl.CERT_REQUIRED )
    ssl_ctx.set_ciphers( 'DHE-RSA-AES256-GCM-SHA384' )
    kwargs[ 'ssl_wrapper' ] = ssl_ctx.wrap_socket
    return librouteros.connect( **kwargs )

def connect_routers( config, args ):
    routers = config.get( 'router', {} )
    rval = {}
    with progress.bar.PixelBar( 'Connecting', max = len( routers ) ) as bar:
        for ( name, kwargs ) in routers.items():
            if ( not args.only ) or ( name in args.only ):
                if 'host' not in kwargs:
                    kwargs[ 'host' ] = name
                rval[ name ] = connection( **kwargs )
            bar.next()
    return rval

def monty_check( config, args, routers ):
    for addr in args.addr:
        for ( name, api ) in routers.items():
            ip_address = api.path( 'ip', 'address' )
            ipv6_address = api.path( 'ipv6', 'address' )
            for item in ip_address:
                ( sel, rval, hst ) = parse_comment( item.get( 'comment', '' ) )
                active = not item[ 'disabled' ] and not item[ 'invalid' ]
                if sel == addr or hst == addr:
                    print( name, ": v4", 'ENABLED' if active else 'disabled', item[ 'interface' ] )
            for item in ipv6_address:
                ( sel, rval, hst ) = parse_comment( item.get( 'comment', '' ) )
                active = not item[ 'disabled' ] and not item[ 'invalid' ]
                if sel == addr or hst == addr:
                    print( name, ": v6", 'ENABLED' if active else 'disabled', item[ 'interface' ] )

def monty_fixup( config, args, routers ):
    reverse = {}
    statics = {}
    for ( name, api ) in routers.items():
        ip_address = api.path( 'ip', 'address' )
        ipv6_address = api.path( 'ipv6', 'address' )
        for item in ip_address:
            ( sel, rval, hst ) = parse_comment( item.get( 'comment', '' ) )
            if sel is None:
                rval = {}
                active = not item[ 'disabled' ] and not item[ 'invalid' ]
                if item[ 'address' ] in config[ 'loopbacks' ]:
                    if active:
                        rval[ 'home' ] = True
                else:
                    rval[ 'static' ] = True
                    statics[ item[ 'interface' ] ] = True
                if not hst:
                    hst = reverse_dns( item[ 'network' ] )
                    while hst.endswith( "." ):
                        hst = hst[ :-1 ]
                if not sel:
                    if item[ 'interface' ] not in reverse:
                        rev = reverse_dns( item[ 'network' ] )
                        while rev.endswith( "." ):
                            rev = rev[ :-1 ]
                        reverse[ item[ 'interface' ] ] = rev
                    sel = rev
                new_comment = make_comment( sel, rval, hst )
                if args.dry_run:
                    print( item[ 'interface' ], item[ 'address' ], '->', new_comment )
                else:
                    print( name, ":", item[ 'interface' ], new_comment )
                    ip_address.update( **{ 'comment': new_comment, '.id': item[ '.id' ] } )
        for item in ipv6_address:
            if item[ 'interface' ].startswith( "loop" ):
                continue
            if item[ 'dynamic' ]:
                continue
            ( sel, rval, hst ) = parse_comment( item.get( 'comment', '' ) )
            if sel is None:
                rval = {}
                active = not item[ 'disabled' ] and not item[ 'invalid' ]
                if statics.get( item[ 'interface' ], False ):
                    rval[ 'static' ] = True
                elif active:
                    rval[ 'home' ] = True
                if not sel:
                    sel = reverse.get( item[ 'interface' ], "XXX " + item[ 'interface' ] )
                if not hst:
                    hst = reverse.get( item[ 'interface' ], "XXX " + item[ 'interface' ] )
                new_comment = make_comment( sel, rval, hst )
                if args.dry_run:
                    print( item[ 'interface' ], item[ 'address' ], '->', new_comment )
                else:
                    print( name, ":", item[ 'interface' ], new_comment )
                    ipv6_address.update( **{ 'comment': new_comment, '.id': item[ '.id' ] } )

def load_configuration():
    try:
        config = open( os.path.expanduser( '~/.automonty.yaml' ), 'r' )
    except IOError:
        return {}
    return yaml.load( config.read(), yaml.SafeLoader )

def main():
    config = load_configuration()

    parser = argparse.ArgumentParser( prog = "automonty",
                                      description = 'AutoMonty (re-)configures routers',
                                      )
    subparsers = parser.add_subparsers()

    parser.add_argument( '--only', action = 'append' )
    parser.add_argument( '-n', '--dry-run', action = 'store_true' )

    parser_check = subparsers.add_parser( 'check' )
    parser_check.add_argument( 'addr', nargs = "*" )
    parser_check.set_defaults( func = monty_check )

    parser_fixup = subparsers.add_parser( 'fixup' )
    parser_fixup.set_defaults( func = monty_fixup )

    args = parser.parse_args()
    routers = connect_routers( config, args )
    args.func( config, args, routers )

if __name__ == '__main__':
    main()