Script to automatically call and connect you to the conference room a minute before your next phone conference starts according to your calendar

extensions.ael

# Of course this is just the (relevant) part of my extensions.ael. Modify this to your needs and add it to the bottom of yours

context connect_remote {
	loc => {
		Dial(${SOURCE});
	}

	rmt => {
		Dial(${DESTINATION},,${CALL_OPTIONS});
	}
}

telko-inviter.py

#!/usr/bin/env python3

from icalendar import Calendar
import requests
from datetime import timedelta as tdelta
from datetime import datetime as dt
from dateutil import rrule as rrule
import re
import hashlib
import os, stat

# Data sources (URL to your ICAL-Files, e.g. Google Calendar export)
calendars = []

# Which Location we are able to parse and which asterisk-channels they are
location_patterns = [
    ("(0[0-9]+)", "SIP/sipgate/\\1"),
    ("(\+[0-9]+)", "SIP/sipgate/\\1"),
    ("tel:(\+?[0-9]+)", "SIP/sipgate/\\1"),
    ("sip:([^\s]+@[^\s]+)", "SIP/\\1"),
]

# How many minutes before the event starts should the call initiated?
graceTime = 1

# How often this script gets called (how long it should check in the future)
resolution = 60 * 60

# Pattern for the generated callfiles. May use Parameters #0: Asterisk-Channel to dial (as defined in location_patterns), #1: DTMF-tones to send, #2: Summary of the event
# Note that you can define the numbers to call using SOURCE (currently +4912345678)
callfilePattern = """
Channel: Local/loc@connect_remote
CallerID: "{2}" <0>
Context: connect_remote
Extension: rmt
Setvar: CALL_OPTIONS=D(ww{1})
Setvar: SOURCE=SIP/sipgate/+4912345678
Setvar: DESTINATION={0}
"""

def create_call(uid, summary, destination, room, dtstart):
    filename = "{}.call".format(hashlib.sha1(uid).hexdigest())
    timestamp = dtstart.timestamp() - 60 * graceTime

    callfile = open("/tmp/call_" + filename, "w")
    callfile.write(callfilePattern.format(destination, room, summary))
    callfile.close()
    os.utime("/tmp/call_" + filename, (timestamp, timestamp))
    os.chmod("/tmp/call_" + filename, stat.S_IRWXU + stat.S_IRWXG + stat.S_IRWXO)
    os.rename("/tmp/call_" + filename, "/var/spool/asterisk/outgoing/" + filename)

match_locations = [(re.compile(pattern), replacement) for pattern, replacement in location_patterns]

class MatchingRRuleException(Exception):
    pass

class NoDateTimeException(Exception):
    pass

class NoPhoneNumberException(Exception):
    pass

def handle_calendar(ical_text):
    cal = Calendar.from_ical(ical_text)

    for event in cal.walk("VEVENT"):
        try:
            uid = event.decoded("uid")
            summary = event.decoded("summary").decode("utf-8")
            location = event.decoded("location").decode("utf-8").split(" ")[0:2]
            dtstart = event.decoded("dtstart")

            # Filter out full-day-events
            if not isinstance(dtstart, dt):
                raise NoDateTimeException()

            # need to compare two values with timezone-data, so use the same timezone as in iCal
            now = dt.now(dtstart.tzinfo)

            # for recurring events, use the next instance
            if "rrule" in event:
                rr_ical = event.decoded("rrule").to_ical().decode("utf-8")
                rr = rrule.rrulestr(rr_ical, dtstart=dtstart)
                dtstart = rr.after(now)
                # Filter events where last recurrence has already happened
                if dtstart is None:
                    raise MatchingRRuleException()

            # search for the destination to use
            destination = None
            for expression, replacement in match_locations:
                match = expression.fullmatch(location[0])
                if match:
                    destination = match.expand(replacement)
                    break

            if destination is None:
                raise NoPhoneNumberException()

            # check if this event should be created now
            if now < dtstart and now + tdelta(seconds=resolution) >= dtstart:
                create_call(uid, summary, destination, location[1], dtstart)
        except (MatchingRRuleException, NoDateTimeException, NoPhoneNumberException):
            pass

for calendar_url in calendars:
    handle_calendar(requests.get(calendar_url).text)

telko-inviter.service

[Unit]
Description=Unit to check for new Telko-Events

[Service]
Type=oneshot
# Change this according to your needs
ExecStart=/usr/local/bin/telko-inviter.py

telko-inviter.timer

[Unit]
Description=Run telko-inviter.py update every 15 minutes

[Timer]
OnBootSec=10min
OnUnitInactiveSec=15min

[Install]
WantedBy=timers.target