vlan-id-reuse.py

#!/usr/bin/env python3
import glob
import re
import xml.etree.ElementTree as et
import json
from datetime import datetime
from collections import namedtuple
from collections import defaultdict


def main():

    # Load up config from each router
    for config_file in glob.glob("../internet2-configs/rtsw/xml/*.xml"):
        print("parsing file {}".format(config_file))
        try:
            ifaces = parse_router_config(config_file)
            for i in ifaces:
                print(i)
        except et.ParseError:
            pass

    # Done


class InterfaceInfo:
    _repr_fields = ("router", "name", "description",
                    "vlan_outer", "vlan_inner")
    router = None
    name = None
    description = None
    vlan_outer = None
    vlan_inner = None

    def __str__(self):
        return "InterfaceInfo({})".format(", ".join([
            "{}={!r}".format(attr, getattr(self, attr))
            for attr
            in self._repr_fields
        ]))


def parse_router_config(rtr_xml_file):
    """Parse a router config.

    Returns a list of InterfaceInfo objects.
    """

    config_root = et.parse(rtr_xml_file)

    # Get Hostname
    rtr_name = extract_hostname(config_root)

    # Get interfaces
    ifaces = extract_interfaces(config_root, rtr_name)

    return ifaces


RE_HOSTNAME_CLEANUP = re.compile(r'-re\d', re.IGNORECASE)


def extract_hostname(config_root):
    """Return the sanitized router hostname"""
    rtr_name = config_root.findtext('.//system/host-name')
    rtr_name = RE_HOSTNAME_CLEANUP.sub('', rtr_name)
    return rtr_name


SKIP_IF_NAMES = set(["all", "fxp0.0", "dsc", "dsc.0"])


def extract_interfaces(config_root, rtr_name):

    # Key is interface_name (w/ unit)
    # Value is InterfaceInfo (which we build up more info on)
    rv = defaultdict(InterfaceInfo)

    # Loop through interfaces
    for iface in config_root.findall('.//interface'):
        if_name = iface.findtext('./name')
        if_descr = iface.findtext('./description')
        if_vlan_id = iface.findtext('./vlan-id')
        if_vlan_outer = iface.findtext('./vlan-tags/outer')
        if_vlan_inner = iface.findtext('./vlan-tags/inner')

        if if_name is None or "*" in if_name or if_name in SKIP_IF_NAMES:
            continue

        # Stash main unit
        rv[if_name].name = if_name
        rv[if_name].router = rtr_name
        rv[if_name].description = if_descr
        if if_vlan_id is not None:
            rv[if_name].vlan_outer = int(if_vlan_id)
        elif if_vlan_outer is not None:
            rv[if_name].vlan_outer = int(if_vlan_outer)
            rv[if_name].vlan_inner = int(if_vlan_inner)

        extract_units(rtr_name, iface, if_name, rv)

    return sorted(rv.values(), key=lambda i: i.name)


def extract_units(rtr_name, iface, if_name, rv):
    for if_unit in iface.findall("./unit"):
        unit_name = if_unit.findtext('./name')
        unit_descr = if_unit.findtext('./description')
        unit_vlan_id = if_unit.findtext('./vlan-id')
        unit_vlan_outer = if_unit.findtext('./vlan-tags/outer')
        unit_vlan_inner = if_unit.findtext('./vlan-tags/inner')
        if unit_name is None or "*" in unit_name:
            continue

        # Stash
        full_name = if_name + "." + unit_name
        rv[full_name].name = full_name
        rv[full_name].router = rtr_name
        rv[full_name].description = unit_descr
        if unit_vlan_id is not None:
            rv[full_name].vlan_outer = int(unit_vlan_id)
        elif unit_vlan_outer is not None:
            rv[full_name].vlan_outer = int(unit_vlan_outer)
            rv[full_name].vlan_inner = int(unit_vlan_inner)


# Main program
if __name__ == "__main__":
    main()