# Copyright 2019-2023 VyOS maintainers and contributors # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library. If not, see . import functools import os from jinja2 import Environment from jinja2 import FileSystemLoader from jinja2 import ChainableUndefined from vyos.defaults import directories from vyos.utils.dict import dict_search_args from vyos.utils.file import makedir from vyos.utils.permission import chmod from vyos.utils.permission import chown # Holds template filters registered via register_filter() _FILTERS = {} _TESTS = {} # reuse Environments with identical settings to improve performance @functools.lru_cache(maxsize=2) def _get_environment(location=None): if location is None: loc_loader=FileSystemLoader(directories["templates"]) else: loc_loader=FileSystemLoader(location) env = Environment( # Don't check if template files were modified upon re-rendering auto_reload=False, # Cache up to this number of templates for quick re-rendering cache_size=100, loader=loc_loader, trim_blocks=True, undefined=ChainableUndefined, extensions=['jinja2.ext.loopcontrols'] ) env.filters.update(_FILTERS) env.tests.update(_TESTS) return env def register_filter(name, func=None): """Register a function to be available as filter in templates under given name. It can also be used as a decorator, see below in this module for examples. :raise RuntimeError: when trying to register a filter after a template has been rendered already :raise ValueError: when trying to register a name which was taken already """ if func is None: return functools.partial(register_filter, name) if _get_environment.cache_info().currsize: raise RuntimeError( "Filters can only be registered before rendering the first template" ) if name in _FILTERS: raise ValueError(f"A filter with name {name!r} was registered already") _FILTERS[name] = func return func def register_test(name, func=None): """Register a function to be available as test in templates under given name. It can also be used as a decorator, see below in this module for examples. :raise RuntimeError: when trying to register a test after a template has been rendered already :raise ValueError: when trying to register a name which was taken already """ if func is None: return functools.partial(register_test, name) if _get_environment.cache_info().currsize: raise RuntimeError( "Tests can only be registered before rendering the first template" ) if name in _TESTS: raise ValueError(f"A test with name {name!r} was registered already") _TESTS[name] = func return func def render_to_string(template, content, formater=None, location=None): """Render a template from the template directory, raise on any errors. :param template: the path to the template relative to the template folder :param content: the dictionary of variables to put into rendering context :param formater: if given, it has to be a callable the rendered string is passed through The parsed template files are cached, so rendering the same file multiple times does not cause as too much overhead. If used everywhere, it could be changed to load the template from Python environment variables from an importable Python module generated when the Debian package is build (recovering the load time and overhead caused by having the file out of the code). """ template = _get_environment(location).get_template(template) rendered = template.render(content) if formater is not None: rendered = formater(rendered) return rendered def render( destination, template, content, formater=None, permission=None, user=None, group=None, location=None, ): """Render a template from the template directory to a file, raise on any errors. :param destination: path to the file to save the rendered template in :param permission: permission bitmask to set for the output file :param user: user to own the output file :param group: group to own the output file All other parameters are as for :func:`render_to_string`. """ # Create the directory if it does not exist folder = os.path.dirname(destination) makedir(folder, user, group) # As we are opening the file with 'w', we are performing the rendering before # calling open() to not accidentally erase the file if rendering fails rendered = render_to_string(template, content, formater, location) # Write to file with open(destination, "w") as file: chmod(file.fileno(), permission) chown(file.fileno(), user, group) file.write(rendered) ################################## # Custom template filters follow # ################################## @register_filter('force_to_list') def force_to_list(value): """ Convert scalars to single-item lists and leave lists untouched """ if isinstance(value, list): return value else: return [value] @register_filter('seconds_to_human') def seconds_to_human(seconds, separator=""): """ Convert seconds to human-readable values like 1d6h15m23s """ from vyos.utils.convert import seconds_to_human return seconds_to_human(seconds, separator=separator) @register_filter('bytes_to_human') def bytes_to_human(bytes, initial_exponent=0, precision=2): """ Convert bytes to human-readable values like 1.44M """ from vyos.utils.convert import bytes_to_human return bytes_to_human(bytes, initial_exponent=initial_exponent, precision=precision) @register_filter('human_to_bytes') def human_to_bytes(value): """ Convert a data amount with a unit suffix to bytes, like 2K to 2048 """ from vyos.utils.convert import human_to_bytes return human_to_bytes(value) @register_filter('ip_from_cidr') def ip_from_cidr(prefix): """ Take an IPv4/IPv6 CIDR host and strip cidr mask. Example: 192.0.2.1/24 -> 192.0.2.1, 2001:db8::1/64 -> 2001:db8::1 """ from ipaddress import ip_interface return str(ip_interface(prefix).ip) @register_filter('address_from_cidr') def address_from_cidr(prefix): """ Take an IPv4/IPv6 CIDR prefix and convert the network to an "address". Example: 192.0.2.0/24 -> 192.0.2.0, 2001:db8::/48 -> 2001:db8:: """ from ipaddress import ip_network return str(ip_network(prefix).network_address) @register_filter('bracketize_ipv6') def bracketize_ipv6(address): """ Place a passed IPv6 address into [] brackets, do nothing for IPv4 """ if is_ipv6(address): return f'[{address}]' return address @register_filter('dot_colon_to_dash') def dot_colon_to_dash(text): """ Replace dot and colon to dash for string Example: 192.0.2.1 => 192-0-2-1, 2001:db8::1 => 2001-db8--1 """ text = text.replace(":", "-") text = text.replace(".", "-") return text @register_filter('generate_uuid4') def generate_uuid4(text): """ Generate random unique ID Example: % uuid4() UUID('958ddf6a-ef14-4e81-8cfb-afb12456d1c5') """ from uuid import uuid4 return uuid4() @register_filter('netmask_from_cidr') def netmask_from_cidr(prefix): """ Take CIDR prefix and convert the prefix length to a "subnet mask". Example: - 192.0.2.0/24 -> 255.255.255.0 - 2001:db8::/48 -> ffff:ffff:ffff:: """ from ipaddress import ip_network return str(ip_network(prefix).netmask) @register_filter('netmask_from_ipv4') def netmask_from_ipv4(address): """ Take IP address and search all attached interface IP addresses for the given one. After address has been found, return the associated netmask. Example: - 172.18.201.10 -> 255.255.255.128 """ from netifaces import interfaces from netifaces import ifaddresses from netifaces import AF_INET for interface in interfaces(): tmp = ifaddresses(interface) if AF_INET in tmp: for af_addr in tmp[AF_INET]: if 'addr' in af_addr: if af_addr['addr'] == address: return af_addr['netmask'] raise ValueError @register_filter('is_ip_network') def is_ip_network(addr): """ Take IP(v4/v6) address and validate if the passed argument is a network or a host address. Example: - 192.0.2.0 -> False - 192.0.2.10/24 -> False - 192.0.2.0/24 -> True - 2001:db8:: -> False - 2001:db8::100 -> False - 2001:db8::/48 -> True - 2001:db8:1000::/64 -> True """ try: from ipaddress import ip_network # input variables must contain a / to indicate its CIDR notation if len(addr.split('/')) != 2: raise ValueError() ip_network(addr) return True except: return False @register_filter('network_from_ipv4') def network_from_ipv4(address): """ Take IP address and search all attached interface IP addresses for the given one. After address has been found, return the associated network address. Example: - 172.18.201.10 has mask 255.255.255.128 -> network is 172.18.201.0 """ netmask = netmask_from_ipv4(address) from ipaddress import ip_interface cidr_prefix = ip_interface(f'{address}/{netmask}').network return address_from_cidr(cidr_prefix) @register_filter('is_interface') def is_interface(interface): """ Check if parameter is a valid local interface name """ return os.path.exists(f'/sys/class/net/{interface}') @register_filter('is_ip') def is_ip(addr): """ Check addr if it is an IPv4 or IPv6 address """ return is_ipv4(addr) or is_ipv6(addr) @register_filter('is_ipv4') def is_ipv4(text): """ Filter IP address, return True on IPv4 address, False otherwise """ from ipaddress import ip_interface try: return ip_interface(text).version == 4 except: return False @register_filter('is_ipv6') def is_ipv6(text): """ Filter IP address, return True on IPv6 address, False otherwise """ from ipaddress import ip_interface try: return ip_interface(text).version == 6 except: return False @register_filter('first_host_address') def first_host_address(text): """ Return first usable (host) IP address from given prefix. Example: - 10.0.0.0/24 -> 10.0.0.1 - 2001:db8::/64 -> 2001:db8:: """ from ipaddress import ip_interface from ipaddress import IPv4Network from ipaddress import IPv6Network addr = ip_interface(text) if addr.version == 4: return str(addr.ip +1) return str(addr.ip) @register_filter('last_host_address') def last_host_address(text): """ Return first usable IP address from given prefix. Example: - 10.0.0.0/24 -> 10.0.0.254 - 2001:db8::/64 -> 2001:db8::ffff:ffff:ffff:ffff """ from ipaddress import ip_interface from ipaddress import IPv4Network from ipaddress import IPv6Network addr = ip_interface(text) if addr.version == 4: return str(IPv4Network(addr).broadcast_address - 1) return str(IPv6Network(addr).broadcast_address) @register_filter('inc_ip') def inc_ip(address, increment): """ Increment given IP address by 'increment' Example (inc by 2): - 10.0.0.0/24 -> 10.0.0.2 - 2001:db8::/64 -> 2001:db8::2 """ from ipaddress import ip_interface return str(ip_interface(address).ip + int(increment)) @register_filter('dec_ip') def dec_ip(address, decrement): """ Decrement given IP address by 'decrement' Example (inc by 2): - 10.0.0.0/24 -> 10.0.0.2 - 2001:db8::/64 -> 2001:db8::2 """ from ipaddress import ip_interface return str(ip_interface(address).ip - int(decrement)) @register_filter('compare_netmask') def compare_netmask(netmask1, netmask2): """ Compare two IP netmask if they have the exact same size. compare_netmask('10.0.0.0/8', '20.0.0.0/8') -> True compare_netmask('10.0.0.0/8', '20.0.0.0/16') -> False """ from ipaddress import ip_network try: return ip_network(netmask1).netmask == ip_network(netmask2).netmask except: return False @register_filter('isc_static_route') def isc_static_route(subnet, router): # https://ercpe.de/blog/pushing-static-routes-with-isc-dhcp-server # Option format is: # , , , , , , # where bytes with the value 0 are omitted. from ipaddress import ip_network net = ip_network(subnet) # add netmask string = str(net.prefixlen) + ',' # add network bytes if net.prefixlen: width = net.prefixlen // 8 if net.prefixlen % 8: width += 1 string += ','.join(map(str,tuple(net.network_address.packed)[:width])) + ',' # add router bytes string += ','.join(router.split('.')) return string @register_filter('is_file') def is_file(filename): if os.path.exists(filename): return os.path.isfile(filename) return False @register_filter('get_dhcp_router') def get_dhcp_router(interface): """ Static routes can point to a router received by a DHCP reply. This helper is used to get the current default router from the DHCP reply. Returns False of no router is found, returns the IP address as string if a router is found. """ lease_file = directories['isc_dhclient_dir'] + f'/dhclient_{interface}.leases' if not os.path.exists(lease_file): return None from vyos.utils.file import read_file for line in read_file(lease_file).splitlines(): if 'option routers' in line: (_, _, address) = line.split() return address.rstrip(';') @register_filter('natural_sort') def natural_sort(iterable): import re from jinja2.runtime import Undefined if isinstance(iterable, Undefined) or iterable is None: return list() def convert(text): return int(text) if text.isdigit() else text.lower() def alphanum_key(key): return [convert(c) for c in re.split('([0-9]+)', str(key))] return sorted(iterable, key=alphanum_key) @register_filter('get_ipv4') def get_ipv4(interface): """ Get interface IPv4 addresses""" from vyos.ifconfig import Interface return Interface(interface).get_addr_v4() @register_filter('get_ipv6') def get_ipv6(interface): """ Get interface IPv6 addresses""" from vyos.ifconfig import Interface return Interface(interface).get_addr_v6() @register_filter('get_ip') def get_ip(interface): """ Get interface IP addresses""" from vyos.ifconfig import Interface return Interface(interface).get_addr() def get_first_ike_dh_group(ike_group): if ike_group and 'proposal' in ike_group: for priority, proposal in ike_group['proposal'].items(): if 'dh_group' in proposal: return 'dh-group' + proposal['dh_group'] return 'dh-group2' # Fallback on dh-group2 @register_filter('get_esp_ike_cipher') def get_esp_ike_cipher(group_config, ike_group=None): pfs_lut = { 'dh-group1' : 'modp768', 'dh-group2' : 'modp1024', 'dh-group5' : 'modp1536', 'dh-group14' : 'modp2048', 'dh-group15' : 'modp3072', 'dh-group16' : 'modp4096', 'dh-group17' : 'modp6144', 'dh-group18' : 'modp8192', 'dh-group19' : 'ecp256', 'dh-group20' : 'ecp384', 'dh-group21' : 'ecp521', 'dh-group22' : 'modp1024s160', 'dh-group23' : 'modp2048s224', 'dh-group24' : 'modp2048s256', 'dh-group25' : 'ecp192', 'dh-group26' : 'ecp224', 'dh-group27' : 'ecp224bp', 'dh-group28' : 'ecp256bp', 'dh-group29' : 'ecp384bp', 'dh-group30' : 'ecp512bp', 'dh-group31' : 'curve25519', 'dh-group32' : 'curve448' } ciphers = [] if 'proposal' in group_config: for priority, proposal in group_config['proposal'].items(): # both encryption and hash need to be specified for a proposal if not {'encryption', 'hash'} <= set(proposal): continue tmp = '{encryption}-{hash}'.format(**proposal) if 'prf' in proposal: tmp += '-' + proposal['prf'] if 'dh_group' in proposal: tmp += '-' + pfs_lut[ 'dh-group' + proposal['dh_group'] ] elif 'pfs' in group_config and group_config['pfs'] != 'disable': group = group_config['pfs'] if group_config['pfs'] == 'enable': group = get_first_ike_dh_group(ike_group) tmp += '-' + pfs_lut[group] ciphers.append(tmp) return ciphers @register_filter('get_uuid') def get_uuid(interface): """ Get interface IP addresses""" from uuid import uuid1 return uuid1() openvpn_translate = { 'des': 'des-cbc', '3des': 'des-ede3-cbc', 'bf128': 'bf-cbc', 'bf256': 'bf-cbc', 'aes128gcm': 'aes-128-gcm', 'aes128': 'aes-128-cbc', 'aes192gcm': 'aes-192-gcm', 'aes192': 'aes-192-cbc', 'aes256gcm': 'aes-256-gcm', 'aes256': 'aes-256-cbc' } @register_filter('openvpn_cipher') def get_openvpn_cipher(cipher): if cipher in openvpn_translate: return openvpn_translate[cipher].upper() return cipher.upper() @register_filter('openvpn_ncp_ciphers') def get_openvpn_ncp_ciphers(ciphers): out = [] for cipher in ciphers: if cipher in openvpn_translate: out.append(openvpn_translate[cipher]) else: out.append(cipher) return ':'.join(out).upper() @register_filter('snmp_auth_oid') def snmp_auth_oid(type): if type not in ['md5', 'sha', 'aes', 'des', 'none']: raise ValueError() OIDs = { 'md5' : '.1.3.6.1.6.3.10.1.1.2', 'sha' : '.1.3.6.1.6.3.10.1.1.3', 'aes' : '.1.3.6.1.6.3.10.1.2.4', 'des' : '.1.3.6.1.6.3.10.1.2.2', 'none': '.1.3.6.1.6.3.10.1.2.1' } return OIDs[type] @register_filter('nft_action') def nft_action(vyos_action): if vyos_action == 'accept': return 'return' return vyos_action @register_filter('nft_rule') def nft_rule(rule_conf, fw_hook, fw_name, rule_id, ip_name='ip'): from vyos.firewall import parse_rule return parse_rule(rule_conf, fw_hook, fw_name, rule_id, ip_name) @register_filter('nft_default_rule') def nft_default_rule(fw_conf, fw_name, family): output = ['counter'] default_action = fw_conf['default_action'] #family = 'ipv6' if ipv6 else 'ipv4' if 'enable_default_log' in fw_conf: action_suffix = default_action[:1].upper() output.append(f'log prefix "[{family}-{fw_name[:19]}-default-{action_suffix}]"') #output.append(nft_action(default_action)) output.append(f'{default_action}') if 'default_jump_target' in fw_conf: target = fw_conf['default_jump_target'] def_suffix = '6' if family == 'ipv6' else '' output.append(f'NAME{def_suffix}_{target}') output.append(f'comment "{fw_name} default-action {default_action}"') return " ".join(output) @register_filter('nft_state_policy') def nft_state_policy(conf, state): out = [f'ct state {state}'] if 'log' in conf: log_state = state[:3].upper() log_action = (conf['action'] if 'action' in conf else 'accept')[:1].upper() out.append(f'log prefix "[STATE-POLICY-{log_state}-{log_action}]"') if 'log_level' in conf: log_level = conf['log_level'] out.append(f'level {log_level}') out.append('counter') if 'action' in conf: out.append(conf['action']) return " ".join(out) @register_filter('nft_intra_zone_action') def nft_intra_zone_action(zone_conf, ipv6=False): if 'intra_zone_filtering' in zone_conf: intra_zone = zone_conf['intra_zone_filtering'] fw_name = 'ipv6_name' if ipv6 else 'name' name_prefix = 'NAME6_' if ipv6 else 'NAME_' if 'action' in intra_zone: if intra_zone['action'] == 'accept': return 'return' return intra_zone['action'] elif dict_search_args(intra_zone, 'firewall', fw_name): name = dict_search_args(intra_zone, 'firewall', fw_name) return f'jump {name_prefix}{name}' return 'return' @register_filter('nft_nested_group') def nft_nested_group(out_list, includes, groups, key): if not vyos_defined(out_list): out_list = [] def add_includes(name): if key in groups[name]: for item in groups[name][key]: if item in out_list: continue out_list.append(item) if 'include' in groups[name]: for name_inc in groups[name]['include']: add_includes(name_inc) for name in includes: add_includes(name) return out_list @register_filter('nat_rule') def nat_rule(rule_conf, rule_id, nat_type, ipv6=False): from vyos.nat import parse_nat_rule return parse_nat_rule(rule_conf, rule_id, nat_type, ipv6) @register_filter('nat_static_rule') def nat_static_rule(rule_conf, rule_id, nat_type): from vyos.nat import parse_nat_static_rule return parse_nat_static_rule(rule_conf, rule_id, nat_type) @register_filter('conntrack_rule') def conntrack_rule(rule_conf, rule_id, action, ipv6=False): ip_prefix = 'ip6' if ipv6 else 'ip' def_suffix = '6' if ipv6 else '' output = [] if 'inbound_interface' in rule_conf: ifname = rule_conf['inbound_interface'] if ifname != 'any': output.append(f'iifname {ifname}') if 'protocol' in rule_conf: if action != 'timeout': proto = rule_conf['protocol'] else: for protocol, protocol_config in rule_conf['protocol'].items(): proto = protocol output.append(f'meta l4proto {proto}') tcp_flags = dict_search_args(rule_conf, 'tcp', 'flags') if tcp_flags and action != 'timeout': from vyos.firewall import parse_tcp_flags output.append(parse_tcp_flags(tcp_flags)) for side in ['source', 'destination']: if side in rule_conf: side_conf = rule_conf[side] prefix = side[0] if 'address' in side_conf: address = side_conf['address'] operator = '' if address[0] == '!': operator = '!=' address = address[1:] output.append(f'{ip_prefix} {prefix}addr {operator} {address}') if 'port' in side_conf: port = side_conf['port'] operator = '' if port[0] == '!': operator = '!=' port = port[1:] output.append(f'th {prefix}port {operator} {port}') if 'group' in side_conf: group = side_conf['group'] if 'address_group' in group: group_name = group['address_group'] operator = '' if group_name[0] == '!': operator = '!=' group_name = group_name[1:] output.append(f'{ip_prefix} {prefix}addr {operator} @A{def_suffix}_{group_name}') # Generate firewall group domain-group elif 'domain_group' in group: group_name = group['domain_group'] operator = '' if group_name[0] == '!': operator = '!=' group_name = group_name[1:] output.append(f'{ip_prefix} {prefix}addr {operator} @D_{group_name}') elif 'network_group' in group: group_name = group['network_group'] operator = '' if group_name[0] == '!': operator = '!=' group_name = group_name[1:] output.append(f'{ip_prefix} {prefix}addr {operator} @N{def_suffix}_{group_name}') if 'port_group' in group: group_name = group['port_group'] if proto == 'tcp_udp': proto = 'th' operator = '' if group_name[0] == '!': operator = '!=' group_name = group_name[1:] output.append(f'{proto} {prefix}port {operator} @P_{group_name}') if action == 'ignore': output.append('counter notrack') output.append(f'comment "ignore-{rule_id}"') else: output.append(f'counter ct timeout set ct-timeout-{rule_id}') output.append(f'comment "timeout-{rule_id}"') return " ".join(output) @register_filter('conntrack_ct_policy') def conntrack_ct_policy(protocol_conf): output = [] for item in protocol_conf: item_value = protocol_conf[item] output.append(f'{item}: {item_value}') return ", ".join(output) @register_filter('range_to_regex') def range_to_regex(num_range): """Convert range of numbers or list of ranges to regex % range_to_regex('11-12') '(1[1-2])' % range_to_regex(['11-12', '14-15']) '(1[1-2]|1[4-5])' """ from vyos.range_regex import range_to_regex if isinstance(num_range, list): data = [] for entry in num_range: if '-' not in entry: data.append(entry) else: data.append(range_to_regex(entry)) return f'({"|".join(data)})' if '-' not in num_range: return num_range regex = range_to_regex(num_range) return f'({regex})' @register_filter('kea_failover_json') def kea_failover_json(config): from json import dumps source_addr = config['source_address'] remote_addr = config['remote'] data = { 'this-server-name': os.uname()[1], 'mode': 'hot-standby', 'heartbeat-delay': 10000, 'max-response-delay': 10000, 'max-ack-delay': 5000, 'max-unacked-clients': 0, 'peers': [ { 'name': os.uname()[1], 'url': f'http://{source_addr}:647/', 'role': 'standby' if config['status'] == 'secondary' else 'primary', 'auto-failover': True }, { 'name': config['name'], 'url': f'http://{remote_addr}:647/', 'role': 'primary' if config['status'] == 'secondary' else 'standby', 'auto-failover': True }] } if 'ca_cert_file' in config: data['trust-anchor'] = config['ca_cert_file'] if 'cert_file' in config: data['cert-file'] = config['cert_file'] if 'cert_key_file' in config: data['key-file'] = config['cert_key_file'] return dumps(data) @register_filter('kea_shared_network_json') def kea_shared_network_json(shared_networks): from vyos.kea import kea_parse_options from vyos.kea import kea_parse_subnet from json import dumps out = [] for name, config in shared_networks.items(): if 'disable' in config: continue network = { 'name': name, 'authoritative': ('authoritative' in config), 'subnet4': [] } options = kea_parse_options(config) if 'subnet' in config: for subnet, subnet_config in config['subnet'].items(): network['subnet4'].append(kea_parse_subnet(subnet, subnet_config)) if options: network['option-data'] = options out.append(network) return dumps(out, indent=4) @register_filter('kea6_shared_network_json') def kea6_shared_network_json(shared_networks): from vyos.kea import kea6_parse_options from vyos.kea import kea6_parse_subnet from json import dumps out = [] for name, config in shared_networks.items(): if 'disable' in config: continue network = { 'name': name, 'subnet6': [] } options = kea6_parse_options(config) if 'interface' in config: network['interface'] = config['interface'] if 'subnet' in config: for subnet, subnet_config in config['subnet'].items(): network['subnet6'].append(kea6_parse_subnet(subnet, subnet_config)) if options: network['option-data'] = options out.append(network) return dumps(out, indent=4) @register_test('vyos_defined') def vyos_defined(value, test_value=None, var_type=None): """ Jinja2 plugin to test if a variable is defined and not none - vyos_defined will test value if defined and is not none and return true or false. If test_value is supplied, the value must also pass == test_value to return true. If var_type is supplied, the value must also be of the specified class/type Examples: 1. Test if var is defined and not none: {% if foo is vyos_defined %} ... {% endif %} 2. Test if variable is defined, not none and has value "something" {% if bar is vyos_defined("something") %} ... {% endif %} Parameters ---------- value : any Value to test from ansible test_value : any, optional Value to test in addition of defined and not none, by default None var_type : ['float', 'int', 'str', 'list', 'dict', 'tuple', 'bool'], optional Type or Class to test for Returns ------- boolean True if variable matches criteria, False in other cases. Implementation inspired and re-used from https://github.com/aristanetworks/ansible-avd/ """ from jinja2 import Undefined if isinstance(value, Undefined) or value is None: # Invalid value - return false return False elif test_value is not None and value != test_value: # Valid value but not matching the optional argument return False elif str(var_type).lower() in ['float', 'int', 'str', 'list', 'dict', 'tuple', 'bool'] and str(var_type).lower() != type(value).__name__: # Invalid class - return false return False else: # Valid value and is matching optional argument if provided - return true return True