icinga2-checks/check_opnsense_traffic_for_host.py

#!/usr/bin/env python3
import argparse
import sys
import time
import traceback
from ipaddress import ip_address, ip_network

import numpy as np
import requests
from urllib3.exceptions import InsecureRequestWarning

import checker.nagios as nagios
from checker.markdown import list_to_markdown_table
from checker.units import filesize


def is_internet_traffic(ip):
    private_networks = [
        ip_network("10.0.0.0/8"),
        ip_network("172.16.0.0/12"),
        ip_network("192.168.0.0/16"),
    ]
    return not any(ip in network for network in private_networks)


def get_traffic_top(args, interface):
    response = requests.get(f'https://{args.opnsense}/api/diagnostics/traffic/top/{interface}',
                            headers={'Accept': 'application/json'}, auth=(args.key, args.secret), verify=False,
                            timeout=10)
    if response.status_code != 200:
        print(f'UNKNOWN: unable to query OPNsense API for {interface}: {response.status_code}\n{response.text}')
        sys.exit(nagios.UNKNOWN)
    return response.json()


def main():
    parser = argparse.ArgumentParser(description='Check OPNsense network traffic for a host.')
    parser.add_argument('--opnsense', required=True, help='OPNsense hostname or IP address.')
    parser.add_argument('--key', required=True, help='OPNsense API key.')
    parser.add_argument('--secret', required=True, help='OPNsense API secret.')
    parser.add_argument('--interface', required=True, help='Interface to check (e.g., lan). Can be something like "lan,wan"')
    parser.add_argument('--host', required=True, help='Address of the host to check.')
    parser.add_argument('--duration', default=10, type=int, help='How many seconds to gather statistics.')
    parser.add_argument('--fail-empty', action='store_true', help='If the API did not return any data, fail with UNKNOWN. Otherwise, assume that there was no traffic.')
    parser.add_argument('--bandwidth', type=float, required=True, help='Bandwidth speed in Mbps. Used to calculate percentage.')
    parser.add_argument('--bandwidth-critical', type=int, default=75, help='Critical if percent of bandwidth usage is greater than or equal to this.')
    parser.add_argument('--bandwidth-warn', type=int, default=50, help='Warning if percent of bandwidth usage is greater than or equal to this.')
    parser.add_argument('--conn-critical', type=int, default=-1, help='Set critical level for number of connections. Default: -1 (disabled).')
    parser.add_argument('--conn-warn', type=int, default=-1, help='Set warning level for number of connections. Default: -1 (disabled).')
    parser.add_argument('--timeout', type=int, default=10, help='Timeout in seconds for the HTTP requests to OPNsense. Default: 10.')
    args = parser.parse_args()

    check_result = {}
    interface_names = {}

    requests.packages.urllib3.disable_warnings(category=InsecureRequestWarning)

    # Map interface names to their internal names
    interfaces_mapping = requests.get(f'https://{args.opnsense}/api/diagnostics/traffic/interface',
                                      headers={'Accept': 'application/json'}, auth=(args.key, args.secret),
                                      verify=False, timeout=args.timeout)
    if interfaces_mapping.status_code != 200:
        print(
            f'UNKNOWN: unable to query OPNsense API for interface mappings: {interfaces_mapping.status_code}\n{interfaces_mapping.text}')
        sys.exit(nagios.UNKNOWN)
    interfaces_mapping = interfaces_mapping.json()['interfaces']
    interfaces_to_check = set(args.interface.split(','))
    for name, interface in interfaces_mapping.items():
        if interface['name'] in interfaces_to_check:
            interfaces_to_check.remove(interface['name'])
            interface_names[interface['name']] = name

    if not len(interface_names.keys()):
        print(f'UNKNOWN: did not find any valid interface names! Double-check the name.')
        sys.exit(nagios.UNKNOWN)

    for name, interface in interface_names.items():
        # Fetch the data
        traffic_data = []
        for _ in range(args.duration):
            start_time = time.time()
            response = requests.get(f'https://{args.opnsense}/api/diagnostics/traffic/top/{interface}',
                                    headers={'Accept': 'application/json'}, auth=(args.key, args.secret), verify=False,
                                    timeout=args.timeout)
            end_time = time.time()
            api_request_time = end_time - start_time

            if response.status_code != 200:
                print(f'UNKNOWN: unable to query OPNsense API for {interface}: {response.status_code}\n{response.text}')
                sys.exit(nagios.UNKNOWN)
            for item in response.json().get(interface, {}).get('records', False):
                if item['address'] == args.host:
                    traffic_data.append(item)

            adjusted_sleep_duration = max(1 - api_request_time, 0)
            time.sleep(adjusted_sleep_duration)

        if not len(traffic_data) and args.fail_empty:
            print('UNKNOWN: Interface or host not found in OPNsense API response. Raw response:')
            print(traffic_data)
            sys.exit(nagios.UNKNOWN)
        elif not len(traffic_data):
            # There was no traffic.
            check_result[name] = {
                'rate_in': 0,
                'rate_out': 0,
                'cumulative_in': 0,
                'cumulative_out': 0,
                'connections': 0
            }
        else:
            try:
                check_result[name] = {
                    'rate_in': np.average([x['rate_bits_in'] for x in traffic_data]),
                    'rate_out': np.average([x['rate_bits_out'] for x in traffic_data]),
                    'cumulative_in': np.average([x['cumulative_bytes_in'] for x in traffic_data]),
                    'cumulative_out': np.average([x['cumulative_bytes_out'] for x in traffic_data]),
                    'connections': int(np.average([len(x['details']) for x in traffic_data]))
                }
            except Exception as e:
                print(f'UNKNOWN: Failed to parse traffic data: "{e}"')
                print(traceback.format_exc())
                print('')
                print('Raw data:')
                print(traffic_data)
                sys.exit(nagios.UNKNOWN)

    warn_b_value = (args.bandwidth * args.bandwidth_warn / 100) * 1e+6
    crit_b_value = (args.bandwidth * args.bandwidth_critical / 100) * 1e+6

    exit_code = nagios.OK
    critical = []
    warn = []
    ok = []
    perf_data = []

    output_table = [
        ('Host', 'Interface', 'Rate In', 'Rate Out', 'Cumulative In', 'Cumulative Out', 'Connections', 'Status')
    ]

    def check_b(name, value):
        nonlocal exit_code
        if value >= crit_b_value:
            critical.append((name, filesize(value)))
            exit_code = nagios.CRITICAL
            return '[CRITICAL]', nagios.CRITICAL
        elif value >= warn_b_value:
            warn.append((name, filesize(value)))
            exit_code = nagios.WARNING
            return '[WARNING]', nagios.WARNING
        else:
            ok.append((name, filesize(value)))
            return '[OK]', nagios.OK

    for name, data in check_result.items():
        status = '[OK]'

        in_status, in_rc = check_b('rate_in', data['rate_in'])
        if in_rc >= exit_code:
            status = in_status

        out_status, out_rc = check_b('rate_out', data['rate_out'])
        if out_rc >= exit_code:
            status = out_status

        if data['connections'] >= args.conn_critical > 0:
            critical.append(('connections', data['connections']))
            exit_code = nagios.CRITICAL
            status = '[CRITICAL]'
        elif data['connections'] >= args.conn_warn > 0:
            warn.append(('connections', data['connections']))
            exit_code = nagios.WARNING
            status = '[WARNING]'
        else:
            ok.append(('connections', data['connections']))

        perf_data.append(f'\'{name}_rate_in\'={int(data["rate_in"])}B;{warn_b_value};{crit_b_value};0;')
        perf_data.append(f'\'{name}_rate_out\'={int(data["rate_out"])}B;{warn_b_value};{crit_b_value};0;')
        perf_data.append(f'\'{name}_cumulative_in\'={int(data["cumulative_in"])}B;{warn_b_value};{crit_b_value};0;')
        perf_data.append(f'\'{name}_cumulative_out\'={int(data["cumulative_out"])}B;{warn_b_value};{crit_b_value};0;')
        perf_data.append(f'\'{name}_connections\'={int(data["connections"])}B;{warn_b_value};{crit_b_value};0;')

        output_table.append((args.host, name, filesize(data['rate_in']), filesize(data['rate_out']),
                             filesize(data['cumulative_in']), filesize(data['cumulative_out']), data['connections'],
                             status))

    if len(critical):
        x = ['CRITICAL: ']
        for i in critical:
            x.append(f'{i[0]}: {i[1]}, ')
        print(''.join(x).strip(', '))
    if len(warn):
        x = ['WARN: ']
        for i in warn:
            x.append(f'{i[0]}: {i[1]}')
        print(''.join(x).strip(', '))
    if not len(warn) and not len(critical):
        print(f'OK: bandwidth is below {args.bandwidth} Mbps.')

    print(list_to_markdown_table(output_table, align='left', seperator='!', borders=False))
    print(f'| {" ".join(perf_data)}')
    sys.exit(exit_code)


if __name__ == "__main__":
    try:
        main()
    except Exception as e:
        print(f'UNKNOWN: exception "{e}"')
        print(traceback.format_exc())
        sys.exit(nagios.UNKNOWN)