junos-routes.py

#!/usr/bin/env python3

from jnpr.junos import Device
from jnpr.junos.op.phyport import PhyPortTable
from getpass import getpass
from lxml import etree
from pathlib import Path
import json
import os
import re
import logging
import sys


logger = logging.getLogger("junos-routes")
logging.basicConfig(format='%(asctime)s %(levelname)-8s %(message)s')
logger.setLevel(logging.DEBUG)

def main():
    h = sys.argv[1] # Router management address
    pw = getpass("Password: ")
    dev = Device(
        host=h,
        user=os.getenv('USER'),
        passwd=pw
    )

    logger.info(f"Connecting to device: {h}")
    dev.open()

    # get-route-information
    logger.debug(f"Facts: {dev.facts!r}")

    # Get interface information
    logger.info("Fetching interface information")
    intf = dev.rpc.get_interface_information(dev_timeout=60)
    (Path("route-snapshot-debug") / f"{h}-interfaces.xml" ).write_text(etree.tostring(intf, encoding='unicode', pretty_print=True))

    # Get all logical interface information
    intf_by_addr = {} # single-ip => {name: ..., prefix: ...}
    for logical_intf in intf.findall("./physical-interface/logical-interface"):
        name = logical_intf.findtext("./name").strip()
        for afi in logical_intf.findall("./address-family"):
            family = afi.findtext(".//address-family-name").strip()
            if family not in ("inet", "inet6"): continue
            local_addr = afi.findtext(".//ifa-local") # 192.168.0.1
            net = afi.findtext(".//ifa-destination") # 192.168.0.0/24, None if loopback
            if local_addr is None or net is None:
                continue
            local_addr = local_addr.strip()
            net = net.strip()
            prefix = local_addr + "/" + net.split("/")[1]
            intf_by_addr[local_addr] = {"name": name, "prefix": prefix}

    # Get neighbor info
    neighbors = []
    logger.info(f"Fetching neighbors")
    rpc_nei = dev.rpc.get_bgp_neighbor_information()
    for nei in rpc_nei.findall('.//bgp-peer'):
        state = nei.findtext('./peer-state')

        vrf = nei.findtext('./peer-cfg-rti')
        local_addr = nei.findtext('./local-address')
        local_addr = local_addr.split('+')[0]
        remote_addr = nei.findtext('./peer-address')
        remote_addr = remote_addr.split('+')[0]
        local_as = nei.findtext('./local-as')
        remote_as = nei.findtext('./peer-as')
        descr = nei.findtext('./description')
        intf_config = intf_by_addr.get(local_addr, {'name': "UNKNOWN INTF", 'prefix': '0.0.0.0/0'})
        if vrf == 'master':
            vrf = 'RE'

        nei_info = {
            'vrf': vrf,
            'local_addr': local_addr,
            'local_as': local_as,
            'remote_addr': remote_addr,
            'remote_as': remote_as,
            'description': descr,
            'intf_prefix': intf_config['prefix'],
        }

        # Skip iBGP
        if local_as == "11537" and remote_as == "11537":
            continue
        # Skip things that aren't in a connected state
        if state != 'Established':
            continue

        neighbors.append(nei_info)

    # print(etree.tostring(reply, encoding='unicode', pretty_print=True))
    # routes = dev.rpc.get_route_information(table='inet.0', dev_timeout=60)

    # Get neighbors
    logger.info("Looping through neighbors")
    for nei in neighbors:
        logger.info(f"Fetching received routes for {nei['vrf']} - {nei['remote_addr']} - {nei['description']}")

        # Fetch routes
        rpc_received = dev.rpc.get_route_information(
            receive_protocol_name="bgp",
            peer=nei['remote_addr'], # Change to the peer address
            level="extensive",
            all="",
            dev_timeout=60
            )


        # Save to JSON
        routes = []
        for rt in rpc_received.findall('.//route-table/rt'):
            dest = rt.findtext('./rt-destination')

            # Skip if it contains both a . and a :, which means it's an l3vpn
            # this is a super lazy way of filtering out l3vpn routes, and I'm
            # not sure this is fool proof
            if re.match(r'.*[.].*[:].*', dest):
                continue
            prefix_len = rt.findtext('./rt-prefix-length')
            prefix = f'{dest}/{prefix_len}'
            as_path = rt.findtext('.//attr-as-path-effective/attr-value')
            # aggregator_as = rt.findtext('.//attr-aggregator/aggr-as-number')
            # aggregator_rid = rt.findtext('.//attr-aggregator/aggr-router-id')
            communities = [c.text for c in rt.findall('.//communities/community')]
            med = int(rt.findtext('.//med') or 0)

            # Cleanup AS-Path
            as_path = re.sub(r' [IE?]$', '', as_path)
            # as_path = [int(asn) for asn in as_path.split(" ")[:-1]]
            # as_path = [asn for asn in as_path.split(" ")[:-1]]

            route = {
                'prefix': prefix,
                'communities': communities,
                'as-path': as_path,
                'med': med,
            }
            logger.debug(f" got route {route!r}")
            routes.append(route)

        base = f"{nei['remote_addr']}-{nei['vrf']}"

        # Save debug info
        (Path("route-snapshot-debug") / f'{base}-routes.xml').write_text(etree.tostring(rpc_received, encoding='unicode', pretty_print=True))

        # Save BGP neighbor information (neighbor info + routes)
        peer_data = nei.copy()
        peer_data['routes'] = routes
        (Path("route-snapshot") / f'{base}.json').write_text(json.dumps(peer_data, sort_keys=True, indent=2))
        # (Path("route-snapshot") / f'{base}-info.json').write_text(json.dumps(nei, sort_keys=True, indent=2))
        # (Path("route-snapshot") / f'{base}-routes.json').write_text(json.dumps(routes, sort_keys=True, indent=2))


    logger.info("DONE")

if __name__ == "__main__":
    main()