calcurse-edge/contrib/caldav/calcurse-caldav.py
Lukas Fleischer d516a8ff87 Add a script to synchronize with CalDAV servers
Introduce calcurse-caldav, a Python script that can be used to
synchronize calcurse instances with CalDAV servers.

The script was tested with an instance of the Radicale CalDAV server but
it is still alpha software. Make backups before giving it a try!

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>
2016-01-22 18:44:42 +01:00

438 lines
13 KiB
Python
Executable File

#!/usr/bin/python3
import argparse
import base64
import configparser
import hashlib
import http.client
import os
import ssl
import subprocess
import sys
import textwrap
import xml.etree.ElementTree as etree
def die(msg):
newmsg = ""
for line in msg.splitlines():
newmsg += textwrap.fill(line, 80) + '\n'
newmsg = newmsg.rstrip('\n')
sys.exit(newmsg)
def die_atnode(msg, node):
if verbose:
msg += '\n\n'
msg += 'The error occurred while processing the following XML node:\n'
msg += etree.tostring(node).decode('utf-8')
die(msg)
def calcurse_wipe():
if verbose:
print('Removing all local calcurse objects...')
if dry_run:
return
subprocess.call([calcurse, '-F', '--filter-hash=XXX'])
def calcurse_import(icaldata):
p = subprocess.Popen([calcurse, '-i', '-', '--list-imported', '-q'],
stdin=subprocess.PIPE, stdout=subprocess.PIPE)
return p.communicate(icaldata.encode('utf-8'))[0].decode('utf-8').rstrip()
def calcurse_export(objhash):
p = subprocess.Popen([calcurse, '-x', 'ical', '--export-uid',
'--filter-hash=' + objhash], stdout=subprocess.PIPE)
return p.communicate()[0].decode('utf-8').rstrip()
def calcurse_hashset():
p = subprocess.Popen([calcurse, '-G'], stdout=subprocess.PIPE)
out = p.communicate()[0]
hashes = set()
for line in out.split(b'\n'):
if not line:
continue
sha1 = hashlib.new('sha1')
sha1.update(line)
hashes.add(sha1.hexdigest())
return hashes
def calcurse_remove(objhash):
subprocess.call([calcurse, '-F', '--filter-hash=!' + objhash])
def calcurse_version():
p = subprocess.Popen([calcurse, '--version'], stdout=subprocess.PIPE)
tokens = p.communicate()[0].decode('utf-8').rstrip().split(" ")
if len(tokens) < 2:
return None
if tokens[0] != 'Calcurse':
return None
tokens = tokens[1].split(".")
if len(tokens) < 2:
return None
return int(tokens[0]) * 10 + int(tokens[1])
def get_auth_headers():
if not username or not password:
return {}
user_password = ('%s:%s' % (username, password)).encode('ascii')
user_password = base64.b64encode(user_password).decode('ascii')
headers = { 'Authorization' : 'Basic %s' % user_password }
return headers
def get_headers():
headers = get_auth_headers()
headers['Content-Type'] = 'Content-Type: text/calendar; charset=utf-8'
return headers
def get_hrefmap(conn, uid=None):
headers = get_headers()
if uid:
propfilter = '<c:prop-filter name="UID">' +\
'<c:text-match collation="i;octet" >%s</c:text-match>' +\
'</c:prop-filter>' % (uid)
else:
propfilter = ''
body = '<c:calendar-query xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:caldav">' +\
'<d:prop><d:getetag /></d:prop><c:filter>' +\
'<c:comp-filter name="VCALENDAR">' + propfilter + '</c:comp-filter>' +\
'</c:filter></c:calendar-query>'
conn.request("REPORT", path, body=body, headers=headers)
resp = conn.getresponse()
resp = resp.read().decode('utf-8')
if not resp:
return {}
root = etree.fromstring(resp)
hrefmap = {}
for node in root.findall(".//D:response", namespaces=nsmap):
etagnode = node.find("./D:propstat/D:prop/D:getetag", namespaces=nsmap)
if etagnode is None:
die_atnode('Missing ETag.', node)
etag = etagnode.text.strip('"')
hrefnode = node.find("./D:href", namespaces=nsmap)
if hrefnode is None:
die_atnode('Missing href.', node)
href = hrefnode.text
hrefmap[etag] = href
return hrefmap
def remote_wipe(conn):
if verbose:
print('Removing all objects from the CalDAV server...')
if dry_run:
return
headers = get_headers()
conn.request("DELETE", path, headers=headers)
resp = conn.getresponse()
if resp:
resp.read()
def get_syncdb(fn):
if not os.path.exists(fn):
return {}
if verbose:
print('Loading synchronization database from ' + fn + '...')
syncdb = {}
with open(fn, 'r') as f:
for line in f.readlines():
etag, objhash = line.rstrip().split(' ')
syncdb[etag] = objhash
return syncdb
def save_syncdb(fn, syncdb):
if verbose:
print('Saving synchronization database to ' + fn + '...')
if dry_run:
return
with open(fn, 'w') as f:
for etag, objhash in syncdb.items():
print("%s %s" % (etag, objhash), file=f)
def push_object(conn, objhash):
href = path + objhash + ".ics"
headers = get_headers()
body = calcurse_export(objhash)
conn.request("PUT", href, body=body, headers=headers)
resp = conn.getresponse()
if not resp:
return None
resp.read()
etag = resp.getheader('ETag')
while not etag:
hrefmap = get_hrefmap(conn, objhash)
if len(hrefmap.keys()) > 0:
etag = hrefmap.keys()[0]
etag = etag.strip('"')
return etag
def remove_remote_object(conn, etag, href):
headers = get_headers()
headers['If-Match'] = '"' + etag + '"'
conn.request("DELETE", href, headers=headers)
resp = conn.getresponse()
if resp:
resp.read()
def push_objects(conn, syncdb, hrefmap):
objhashes = calcurse_hashset()
new = objhashes - set(syncdb.values())
gone = set(syncdb.values()) - objhashes
added = deleted = 0
# Copy new objects to the server.
for objhash in new:
if verbose:
print("Pushing new object %s to the server." % (objhash))
if dry_run:
continue
etag = push_object(conn, objhash)
syncdb[etag] = objhash
added += 1
# Remove locally deleted objects from the server.
for objhash in gone:
deletags = []
for key, value in syncdb.items():
if value == objhash:
deletags.append(key)
for etag in deletags:
if not etag in hrefmap:
continue
href = hrefmap[etag]
if verbose:
print("Removing remote object %s (%s)." % (etag, href))
if dry_run:
continue
remove_remote_object(conn, etag, href)
syncdb.pop(etag, None)
deleted += 1
return (added, deleted)
def pull_objects(conn, syncdb, hrefmap):
missing = set(hrefmap.keys()) - set(syncdb.keys())
orphan = set(syncdb.keys()) - set(hrefmap.keys())
# Download and import new objects from the server.
headers = get_headers()
body = '<c:calendar-multiget xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:caldav">' +\
'<d:prop><d:getetag /><c:calendar-data /></d:prop>'
for etag in missing:
body += '<d:href>%s</d:href>' % (hrefmap[etag])
body += '</c:calendar-multiget>'
conn.request("REPORT", path, body=body, headers=headers)
resp = conn.getresponse()
if not resp:
return
resp = resp.read().decode('utf-8')
root = etree.fromstring(resp)
added = deleted = 0
for node in root.findall(".//D:prop", namespaces=nsmap):
etagnode = node.find("./D:getetag", namespaces=nsmap)
if etagnode is None:
die_atnode('Missing ETag.', node)
etag = etagnode.text.strip('"')
cdatanode = node.find("./C:calendar-data", namespaces=nsmap)
if cdatanode is None:
die_atnode('Missing calendar data.', node)
cdata = cdatanode.text
if verbose:
print("Importing new object %s." % (etag))
if dry_run:
continue
objhash = calcurse_import(cdata)
syncdb[etag] = objhash
added += 1
# Delete objects that no longer exist on the server.
for etag in orphan:
objhash = syncdb[etag]
if verbose:
print("Removing local object %s." % (objhash))
if dry_run:
continue
calcurse_remove(objhash)
syncdb.pop(etag, None)
deleted += 1
return (added, deleted)
# Initialize the XML namespace map.
nsmap = { "D": "DAV:", "C": "urn:ietf:params:xml:ns:caldav" }
# Initialize default values.
configfn = os.path.expanduser("~/.calcurse/caldav/config")
lockfn = os.path.expanduser("~/.calcurse/caldav/lock")
syncdbfn = os.path.expanduser("~/.calcurse/caldav/sync.db")
# Parse command line arguments.
parser = argparse.ArgumentParser('calcurse-caldav')
parser.add_argument('--init', action='store', dest='init', default=None,
choices=['keep-remote', 'keep-local', 'two-way'],
help='initialize the sync database')
parser.add_argument('--config', action='store', dest='configfn',
default=configfn,
help='path to the calcurse-caldav configuration')
parser.add_argument('--lockfile', action='store', dest='lockfn',
default=lockfn,
help='path to the calcurse-caldav lock file')
parser.add_argument('--syncdb', action='store', dest='syncdbfn',
default=syncdbfn,
help='path to the calcurse-caldav sync DB')
parser.add_argument('-v', '--verbose', action='store_true', dest='verbose',
default=False,
help='print status messages to stdout')
args = parser.parse_args()
init = args.init is not None
configfn = args.configfn
lockfn = args.lockfn
syncdbfn = args.syncdbfn
verbose = args.verbose
# Read configuration.
config = configparser.RawConfigParser()
if verbose:
print('Loading configuration from ' + configfn + '...')
try:
config.readfp(open(configfn))
except FileNotFoundError as e:
die('Configuration file not found: %s' % (configfn))
hostname = config.get('General', 'HostName')
path = config.get('General', 'Path').rstrip('/') + '/'
insecure_ssl = config.getboolean('General', 'InsecureSSL')
if config.has_option('General', 'Binary'):
calcurse = config.get('General', 'Binary')
else:
calcurse = 'calcurse'
if config.has_option('General', 'DryRun'):
dry_run = config.getboolean('General', 'DryRun')
else:
dry_run = True
if not verbose and config.has_option('General', 'Verbose'):
dry_run = config.getboolean('General', 'Verbose')
if config.has_option('Auth', 'UserName'):
username = config.get('Auth', 'UserName')
else:
username = None
if config.has_option('Auth', 'Password'):
password = config.get('Auth', 'Password')
else:
password = None
# Show disclaimer when performing a dry run.
if dry_run:
print('Dry run. Nothing is actually imported/exported.')
print('Edit the configuration file and add "DryRun = No" to the [General] section')
print('to enable synchronization.')
# Check whether the specified calcurse binary is executable and compatible.
ver = calcurse_version()
if ver is None:
die('Invalid calcurse binary. Make sure that the file specified in ' +
'the configuration is a valid and up-to-date calcurse binary.')
elif ver < 40:
die('Incompatible calcurse binary detected. Version >=4.0.0 is required ' +
'to synchronize with CalDAV servers.')
# Create lock file.
if os.path.exists(lockfn):
die('Leftover lock file detected. If there is no other synchronization ' +
'instance running, please remove the lock file manually and try ' +
'again.')
open(lockfn, 'w')
try:
# Connect to the server via HTTPs.
if insecure_ssl:
context = ssl._create_unverified_context()
else:
context = ssl._create_default_https_context()
if verbose:
print('Connecting to ' + hostname + '...')
conn = http.client.HTTPSConnection(hostname, context=context)
if init:
# In initialization mode, start with an empty synchronization database.
if (args.init == 'keep-remote'):
calcurse_wipe()
elif (args.init == 'keep-local'):
remote_wipe(conn)
syncdb = {}
else:
# Read the synchronization database.
syncdb = get_syncdb(syncdbfn)
if not syncdb:
die('Sync database not found or empty. Please initialize the ' +
'database first.\n\nSupported initialization modes are:\n' +
' --init=keep-remote Remove all local calcurse items and import remote objects\n' +
' --init=keep-local Remove all remote objects and push local calcurse items\n' +
' --init=two-way Copy local objects to the CalDAV server and vice versa')
# Query the server and build a dictionary that maps ETags to paths on the
# server.
hrefmap = get_hrefmap(conn)
# Retrieve new objects from the server, delete local items that no longer
# exist on the server.
local_new, local_del = pull_objects(conn, syncdb, hrefmap)
# Push new objects to the server, remove items from the server if they no
# longer exist locally.
remote_new, remote_del = push_objects(conn, syncdb, hrefmap)
# Write the synchronization database.
save_syncdb(syncdbfn, syncdb)
# Close the HTTPs connection.
conn.close()
finally:
# Remove lock file.
os.remove(lockfn)
# Print a summary to stdout.
print("%d items imported, %d items removed locally." % (local_new, local_del))
print("%d items exported, %d items removed from the server." %
(remote_new, remote_del))