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| -rw-r--r-- | contrib/caldav/README | 50 | ||||
| -rwxr-xr-x | contrib/caldav/calcurse-caldav.py | 437 | ||||
| -rw-r--r-- | contrib/caldav/config.sample | 31 |
3 files changed, 518 insertions, 0 deletions
diff --git a/contrib/caldav/README b/contrib/caldav/README new file mode 100644 index 0000000..72ad1a9 --- /dev/null +++ b/contrib/caldav/README @@ -0,0 +1,50 @@ +calcurse-caldav +=============== + +calcurse-caldav is a simple Python script that can be used to synchronize +calcurse with a CalDAV server. Please note that the script is alpha software! +This means that: + +* We are eagerly looking for testers to run the script and give feedback! If + you find any bugs, please report them to the calcurse mailing lists or to the + GitHub bug tracker. If the script works fine for you, please report back as + well! + +* The script might still have bugs. Make backups, especially before running + calcurse-caldav for the first time! + +Usage +----- + +calcurse-caldav requires an up-to-date version of calcurse and a configuration +file located at ~/.calcurse/caldav/config. An example configuration file can be +found under contrib/caldav/config.sample in the calcurse source tree. + +If you run calcurse-caldav for the first time, you need to provide the --init +argument. You can choose between the following initialization modes: + + --init=keep-remote Remove all local calcurse items and import remote objects + --init=keep-local Remove all remote objects and push local calcurse items + --init=two-way Copy local objects to the CalDAV server and vice versa + +For subsequent calcurse-caldav invocations, you don't need to specify any +additional parameters. + +How It Works +------------ + +calcurse-caldav creates a so-called synchronization database at +~/.calcurse/caldav/sync.db that always keeps a snapshot of the last time the +script was executed. When running the script, it compares the objects on the +server and the local objects with that snapshot to identify items that were +added or deleted. It then + +* downloads new objects from the server and imports them into calcurse, +* deletes local objects that no longer exist on the server, +* uploads objects to the server that were added locally, +* deleted objects from the server that were deleted locally, +* updates the synchronization database with the new snapshot. + +Note that, since calcurse does not use unique identifiers for items, it cannot +keep track of moved/edited items. Thus, changing an item is equivalent to +deleting the old item and creating a new one. diff --git a/contrib/caldav/calcurse-caldav.py b/contrib/caldav/calcurse-caldav.py new file mode 100755 index 0000000..94d1775 --- /dev/null +++ b/contrib/caldav/calcurse-caldav.py @@ -0,0 +1,437 @@ +#!/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)) diff --git a/contrib/caldav/config.sample b/contrib/caldav/config.sample new file mode 100644 index 0000000..e2b3abe --- /dev/null +++ b/contrib/caldav/config.sample @@ -0,0 +1,31 @@ +# If you want to synchronize calcurse with a CalDAV server using +# calcurse-caldav, create a new directory ~/.calcurse/caldav/, copy this file +# to ~/.calcurse/caldav/config and adjust the configuration below. + +[General] +# Path to the calcurse binary that is used for importing/exporting items. +Binary = calcurse + +# Host name of the server that hosts CalDAV. +Hostname = some.hostname.com + +# Path to the CalDAV calendar on the host specified above. +Path = /path/to/calendar/on/the/server/ + +# Enable this if you want to skip SSL certificate checks. +InsecureSSL = No + +# Disable this option to actually enable synchronization. If it is enabled, +# nothing is actually written to the server or to the local data files. If you +# combine DryRun = Yes with Verbose = Yes, you get a log of what would have +# happened with this option disabled. +DryRun = Yes + +# Enable this if you want detailed logs written to stdout. +Verbose = Yes + +# Credentials for HTTP Basic Authentication. Leave this commented out if you do +# not want to use authentication. +#[Auth] +#Username = user +#Password = pass |