Import a ics file into your CalDav Server

ics2caldav.py

#!/usr/bin/env python3

import logging
import sys
import vobject
import requests
from requests.auth import HTTPBasicAuth
from requests.packages.urllib3.poolmanager import PoolManager

# https://stackoverflow.com/questions/26479039/python-requests-direct-pem-pinning-with-self-signed-cert
class _FingerprintAdapter(requests.adapters.HTTPAdapter):
    def __init__(self, fingerprint=None, **kwargs):
        self.fingerprint = str(fingerprint)
        super(_FingerprintAdapter, self).__init__(**kwargs)

    def init_poolmanager(self, connections, maxsize, block=False):
        self.poolmanager = PoolManager(
          num_pools=connections,
          maxsize=maxsize,
          block=block,
          assert_fingerprint=self.fingerprint)

class CalDavImporter():
  def __init__(self):
    self.dav_url = 'https://caldav.example.com'
    self.dav_session = requests.Session()
    self.dav_session.auth = HTTPBasicAuth('<user>', '<pass>')
    self.dav_session.mount(self.dav_url, _FingerprintAdapter('<certificate fingerprint>'))
    self.dav_session.verify = False

  def download_ics(self, url: str):
    r = requests.get(url, stream=True)
    return vobject.readOne(r.text)

  def dav_upload(self, prefix: str, vevent):
    uid = vevent.getChildValue('uid')

    if len(uid) < 5:
      logging.warning("Reject uploading uid: %s" % uid)
      return

    cal = vobject.newFromBehavior('vcalendar')
    cal.vevent = vevent

    self.dav_session.put("%s/%s_%s.ics" % (self.dav_url, prefix, uid),
      data=cal.serialize(),
      headers={'Content-Type': 'text/calendar'})

  def update_calendar(self, prefix: str, url: str):
    cal = self.download_ics(url)
    
    events = []
    for e in cal.getChildren():
      if e.name == 'VEVENT':
        events.append(e)

    for e in events:
        self.dav_upload(prefix, e)

if __name__ == '__main__':
  logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)

  importer = CalDavImporter()
  importer.update_calendar('<prefix>', 'https://download.example.com/file-to-import.ics')