ciscolive/automation/services/dns-hook.py

#!/usr/local/bin/python3
#
# Copyright (c) 2017-2020  Joe Clarke <jclarke@cisco.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

from __future__ import print_function
import sys
import json
from sparker import Sparker, MessageType
import re
import requests
from requests.packages.urllib3.exceptions import InsecureRequestWarning

requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
import time
import traceback
import socket
import logging
import CLEUCreds
from cleu.config import Config as C

CNR_HEADERS = {"Accept": "application/json", "Content-Type": "application/json", "Authorization": CLEUCreds.JCLARKE_BASIC}

ALLOWED_TO_CREATE = [
    "jclarke@cisco.com",
    "ksekula@cisco.com",
    "ayourtch@cisco.com",
    "rkamerma@cisco.com",
    "thulsdau@cisco.com",
    "lhercot@cisco.com",
    "pweijden@cisco.com",
    "udiedric@cisco.com",
]

spark = Sparker(token=CLEUCreds.SPARK_TOKEN, logit=True)

SPARK_ROOM = "DNS Queries"


def check_for_alias(alias):
    global CNR_HEADERS

    url = C.DNS_BASE + "CCMRRSet" + "/{}".format(alias)

    response = requests.request("GET", url, params={"zoneOrigin": C.DNS_DOMAIN}, headers=CNR_HEADERS, verify=False)
    if response.status_code == 404:
        return None

    res = {}
    j = response.json()

    hostname = ""

    for rr in j["rrs"]["stringItem"]:
        m = re.search(r"^IN CNAME (.+)", rr)
        if m:
            hostname = m.group(1)
            break

    res["hostname"] = hostname

    return res


def create_alias(hostname, alias):
    global CNR_HEADERS

    url = C.DNS_BASE + "CCMRRSet" + "/{}".format(alias)

    if re.search(r"\.", hostname) and not hostname.endswith("."):
        hostname += "."

    if not hostname.endswith("."):
        hostname += "." + C.DNS_DOMAIN + "."

    rr_obj = {"name": alias, "zoneOrigin": C.DNS_DOMAIN, "rrs": {"stringItem": ["IN CNAME {}".format(hostname)]}}

    response = requests.request("PUT", url, headers=CNR_HEADERS, json=rr_obj, verify=False)
    response.raise_for_status()


def delete_alias(alias):
    global CNR_HEADERS

    url = C.DNS_BASE + "CCMRRSet" + "/{}".format(alias)

    response = requests.request("DELETE", url, params={"zoneOrigin": C.DNS_DOMAIN}, headers=CNR_HEADERS, verify=False)
    response.raise_for_status()


def delete_record(hostname):
    global CNR_HEADERS

    url = C.DNS_BASE + "CCMHost" + "/{}".format(hostname)

    response = requests.request("DELETE", url, params={"zoneOrigin": C.DNS_DOMAIN}, headers=CNR_HEADERS, verify=False)
    response.raise_for_status()


def check_for_record(hostname):
    global CNR_HEADERS

    url = C.DNS_BASE + "CCMHost" + "/{}".format(hostname)

    response = requests.request("GET", url, params={"zoneOrigin": C.DNS_DOMAIN}, headers=CNR_HEADERS, verify=False)
    if response.status_code == 404:
        return None

    res = {}
    j = response.json()

    res["ip"] = j["addrs"]["stringItem"][0]

    return res


def create_record(hostname, ip, aliases):
    global CNR_HEADERS

    url = C.DNS_BASE + "CCMHost" + "/{}".format(hostname)
    host_obj = {"addrs": {"stringItem": [ip]}, "name": hostname, "zoneOrigin": C.DNS_DOMAIN}

    if aliases is not None:
        aliases = re.sub(r"\s+", "", aliases)
        alist = aliases.split(",")

        alist = [x + "." + C.DNS_DOMAIN + "." if not x.endswith(".") else x for x in alist]
        host_obj["aliases"] = {"stringItem": alist}

    response = requests.request("PUT", url, headers=CNR_HEADERS, json=host_obj, verify=False)
    response.raise_for_status()


if __name__ == "__main__":
    print("Content-type: application/json\r\n\r\n")

    output = sys.stdin.read()

    j = json.loads(output)

    logging.basicConfig(
        format="%(asctime)s - %(name)s - %(levelname)s : %(message)s", filename="/var/log/dns-hook.log", level=logging.DEBUG
    )
    logging.debug(json.dumps(j, indent=4))

    message_from = j["data"]["personEmail"]

    if message_from == "livenocbot@sparkbot.io":
        logging.debug("Person email is our bot")
        print('{"result":"success"}')
        sys.exit(0)

    tid = spark.get_team_id(C.WEBEX_TEAM)
    if tid is None:
        logging.error("Failed to get Spark Team ID")
        print('{"result":"fail"}')
        sys.exit(0)

    rid = spark.get_room_id(tid, SPARK_ROOM)
    if rid is None:
        logging.error("Failed to get Spark Room ID")
        print('{"result":"fail"}')
        sys.exit(0)

    if rid != j["data"]["roomId"]:
        logging.error("Spark Room ID is not the same as in the message ({} vs. {})".format(rid, j["data"]["roomId"]))
        print('{"result":"fail"}')
        sys.exit(0)

    mid = j["data"]["id"]

    msg = spark.get_message(mid)
    if msg is None:
        logging.error("Did not get a message")
        print('{"result":"error"}')
        sys.exit(0)

    txt = msg["text"]
    found_hit = False

    if re.search(r"\bhelp\b", txt, re.I):
        spark.post_to_spark(
            C.WEBEX_TEAM,
            SPARK_ROOM,
            "To create a new DNS entry, tell me things like, `Create record for HOST with IP and alias ALIAS`, `Create entry for HOST with IP`, `Add a DNS record for HOST with IP`",
        )
        found_hit = True

    try:
        m = re.search(r"(remove|delete)\s+.*?(alias|cname)\s+([\w\-\.]+)", txt, re.I)

        if not found_hit and m:
            found_hit = True
            if message_from not in ALLOWED_TO_CREATE:
                spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "I'm sorry, {}.  I can't do that for you.".format(message_from))
            else:
                res = check_for_alias(m.group(3))
                if res is None:
                    spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "I didn't find an alias {}".format(m.group(3)))
                else:
                    try:
                        delete_alias(m.group(3))
                        spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "Alias {} deleted successfully.".format(m.group(3)), MessageType.GOOD)
                    except Exception as e:
                        spark.post_to_spark(
                            C.WEBEX_TEAM, SPARK_ROOM, "Failed to delete alias {}: {}".format(m.group(3), e), MessageType.BAD
                        )

        m = re.search(r"(remove|delete)\s+.*?for\s+([\w\-\.]+)", txt, re.I)

        if not found_hit and m:
            found_hit = True
            if message_from not in ALLOWED_TO_CREATE:
                spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "I'm sorry, {}.  I can't do that for you.".format(message_from))
            else:
                res = check_for_record(m.group(2))
                if res is None:
                    spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "I didn't find a DNS record for {}.".format(m.group(2)))
                else:
                    try:
                        delete_record(m.group(2))
                        spark.post_to_spark(
                            C.WEBEX_TEAM, SPARK_ROOM, "DNS record for {} deleted successfully.".format(m.group(2)), MessageType.GOOD
                        )
                    except Exception as e:
                        spark.post_to_spark(
                            C.WEBEX_TEAM, SPARK_ROOM, "Failed to delete DNS record for {}: {}".format(m.group(2), e), MessageType.BAD
                        )

        m = re.search(
            r"(make|create|add)\s+.*?for\s+([\w\-\.]+)\s+.*?([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)(\s+.*?(alias(es)?|cname(s)?)\s+([\w\-\.]+(\s*,\s*[\w\-\.,\s]+)?))?",
            txt,
            re.I,
        )
        if not found_hit and m:
            found_hit = True
            if message_from not in ALLOWED_TO_CREATE:
                spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "I'm sorry, {}.  I can't do that for you.".format(message_from))
            else:
                res = check_for_record(m.group(2))
                if res is not None:
                    spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "_{}_ is already in DNS as **{}**".format(m.group(2), res["ip"]))
                else:
                    hostname = re.sub(r"\.{}".format(C.DNS_DOMAIN), "", m.group(2))
                    try:
                        create_record(m.group(2), m.group(3), m.group(8))
                        spark.post_to_spark(
                            C.WEBEX_TEAM, SPARK_ROOM, "Successfully created record for {}.".format(m.group(2)), MessageType.GOOD
                        )
                    except Exception as e:
                        spark.post_to_spark(
                            C.WEBEX_TEAM, SPARK_ROOM, "Failed to create record for {}: {}".format(m.group(2), e), MessageType.BAD
                        )

        m = re.search(r"(make|create|add)\s+(alias(es)?|cname(s)?)\s+([\w\-\.]+(\s*,\s*[\w\-\.,\s]+)?)\s+(for|to)\s+([\w\-\.]+)", txt, re.I)
        if not found_hit and m:
            found_hit = True
            if message_from not in ALLOWED_TO_CREATE:
                spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "I'm sorry, {}.  I can't do that for you.".format(message_from))
            else:
                aliases = m.group(5)
                aliases = re.sub(r"\s+", "", aliases)
                alist = aliases.split(",")
                already_exists = False
                for alias in alist:
                    res = check_for_alias(alias)
                    if res is not None:
                        already_exists = True
                        spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "_{}_ is already an alias for **{}**".format(alias, res["hostname"]))
                    res = check_for_record(alias)
                    if res is not None:
                        already_exists = True
                        spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "_{}_ is already a hostname with IP **{}**".format(alias, res["ip"]))

                if not already_exists:
                    success = True
                    for alias in alist:
                        try:
                            create_alias(m.group(8), alias)
                        except Exception as e:
                            spark.post_to_spark(C.WEBEX_TEAM, SPARK_ROOM, "Failed to create alias {}: {}".format(alias, e), MessageType.BAD)
                            success = False

                    if success:
                        spark.post_to_spark(
                            C.WEBEX_TEAM,
                            SPARK_ROOM,
                            "Successfully created alias(es) {} for {}".format(aliases, m.group(8)),
                            MessageType.GOOD,
                        )

        if not found_hit:
            spark.post_to_spark(
                C.WEBEX_TEAM,
                SPARK_ROOM,
                'Sorry, I didn\'t get that.  Please ask me to create or delete a DNS entry; or just ask for "help".',
            )
    except Exception as e:
        logging.error("Error in obtaining data: {}".format(traceback.format_exc()))
        spark.post_to_spark(
            C.WEBEX_TEAM, SPARK_ROOM, "Whoops, I encountered an error:<br>\n```\n{}\n```".format(traceback.format_exc()), MessageType.BAD
        )

    print('{"result":"success"}')