Pyng: DNSL check

Description

DNSL check provides flexible facilities to query DNS-based lists.

DNSL requires drill command to be present in $PATH.

Options

DNSL supports following options, which may be used upon creation of a new check object:

qaddr

Address to look up (required)

qzone

DNS zone for the search

qtype

Query type

reverse

Set to True to cause the check to fail if lookup returns nothing (useful for DNS whitelists)

dnssec

Set to True to enable DNSSEC in the query

server

Target server for the query

port

Port to connect to instead of the default of 53

proto

TCP or UDP transport for the connection

ipv

IP version to use when resolving addresses (IPv6 or IPv4)

In addition, DNSL supports following generic check settings:

desc

Check description

silent

Information about check runs is not output by certain runners

interval

Number of seconds between check runs

result

Require that check output matches result in order to consider check successful. During the matching, check output is evaluated as a list of lines of output without newlines. result may be provided in multiple ways:

• None: always succeeds
• string: succeeds if any line in the check's output is equal to, or contains, result
• list or a tuple: succeeds if all elements of result are present in the check's output (i.e. set of result items is a subset of check output items)
• set: succeeds if all lines in the check's output are present in result (i.e. check output is a subset of the set of result items)
• Compiled regular expression object: succeeds if any line in the check's output matches result

alert

Callable (or a list of callables) to run in order to alert of check status changes

notify

Callable (or a list of callables) to run in order to notify of changes in check's output

run_condition

Callable to run to decide if check run should be skipped

run_threshold

Threshold for mean run time in order to consider check to be degraded

result_filter

Callable to run to filter check command output lines prior to matching check results

on_result

on_first

on_up

on_down

on_degrade

on_restore

on_change

Callable to run with the result of the check on the specified events

Example

# check DNS blacklist: address should not be listed
DNSL(
    '1.2.3.4', 'zen.spamhaus.org',
    server='localhost',
)

# check DNS whitelist: address should be listed
DNSL(
    '1.2.3.4', 'list.dnswl.org',
    reverse=True,
    server='localhost',
)