CiscoConfParse Complex Example

In addition to the CLI tool, ciscoconfparse2 also offers a Python API.

This example code parses a configuration stored in tests/fixtures/configs/sample_08.ios and will find the IP address / switchport parameters assigned to interfaces.

Save this code in a file named example.py

"""
Walk all interfaces in a Cisco IOS configuration (from the
ciscoconfparse2 test fixtures): build a CSV with details about
the interface.

Save this script as example.py
"""

from ciscoconfparse2 import CiscoConfParse
from ciscoconfparse2 import IPv4Obj
from ciscoconfparse2 import BaseCfgLine


def intf_csv(intf_obj: BaseCfgLine) -> str:
    """
    :return: CSV for each interface object.
    :rtype: str
    """

    # intf_obj is an BaseCfgLine() subclass containing
    #   something like 'interface Loopback0'
    intf_name = " ".join(intf_obj.split()[1:])

    admin_status = intf_obj.re_match_iter_typed(
        "^\s+(shutdown)", default="not_shutdown", result_type=str
    )

    # Search children of all interfaces for a regex match and return
    # the value matched in regex match group 1.  If there is no match,
    # return a default value: 0.0.0.1/32
    addr_netmask = intf_obj.re_match_iter_typed(
        r"^\s+ip\saddress\s(\d+\.\d+\.\d+\.\d+\s\S+)",
        result_type=IPv4Obj,
        group=1,
        default=IPv4Obj("0.0.0.1/32"),
    )

    # Find the description and replace all commas in it
    description = intf_obj.re_match_iter_typed("description\s+(\S.*)").replace(",", "_")

    switchport_status = intf_obj.re_match_iter_typed(
        "(switchport)", default="not_switched"
    )

    # Return a csv based on whether this is a switchport
    if switchport_status == "not_switched":
        return f"{intf_name},{admin_status},{addr_netmask.as_cidr_addr},{switchport_status},,,{description}"

    else:
        # Only calculate switchport values if this is a switchport
        trunk_access = intf_obj.re_match_iter_typed(
            "switchport mode (trunk)", default="access", result_type=str
        )
        access_vlan = intf_obj.re_match_iter_typed(
            "switchport access vlan (\d+)", default=1, result_type=int
        )

        # Return the CSV string of values...
        return f"{intf_name},{admin_status},{switchport_status},{trunk_access},{access_vlan},{description}"


parse = CiscoConfParse("tests/fixtures/configs/sample_08.ios", syntax="ios")

# Find interface BaseCfgLine() instances...
for intf_obj in parse.find_objects("^interface"):
    print(intf_csv(intf_obj))

That will print a CSV with detailed interface information in it:

$ python example.py
Loopback0,not_shutdown,172.16.0.1/32,not_switched,,,SEE http://www.cymru.com/Documents/secure-ios-template.html
Null0,not_shutdown,0.0.0.1/32,not_switched,,,
ATM0/0,not_shutdown,0.0.0.1/32,not_switched,,,
ATM0/0.32 point-to-point,not_shutdown,0.0.0.1/32,not_switched,,,
FastEthernet0/0,not_shutdown,172.16.2.1/24,not_switched,,,[IPv4 and IPv6 desktop / laptop hosts on 2nd-floor North LAN]
FastEthernet0/1,not_shutdown,172.16.3.1/30,not_switched,,,[IPv4 and IPv6 OSPF Transit via West side of building]
FastEthernet1/0,not_shutdown,172.16.4.1/30,not_switched,,,[IPv4 and IPv6 OSPF Transit via North side of building]
FastEtheret1/1,not_shutdown,,switchport,access,12,[switchport to the comptroller cube]
FastEtheret1/2,not_shutdown,,switchport,access,12,[switchport to the IDF media converter]
Virtual-Template1,not_shutdown,0.0.0.1/32,not_switched,,,
Dialer1,not_shutdown,0.0.0.1/32,not_switched,,,[IPv4 and IPv6 OSPF Transit via WAN Dialer: NAT_ CBWFQ interface]