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!
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. You will
also need to install httplib2 for Python 3 using pip (e.g.
--user httplib2) or your distribution’s package manager.
If you run calcurse-caldav for the first time, you need to provide the
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.
You can specify a username and password for basic authentication in the
config file. Alternatively, the password can be passed securely from another
program (such as pass) via the
CALCURSE_CALDAV_PASSWORD environment variable like
CALCURSE_CALDAV_PASSWORD=$(pass show calcurse) calcurse-caldav
You can place scripts in
$HOME/.calcurse/caldav/hooks/ to trigger actions at
certain events. To enable a hook, add a script with one of the following names
to this directory. Also make sure the scripts are executable.
Executed before the data files are synchronized.
Executed after the data files are synchronized.
Some examples can be found in the
contrib/caldav/hooks/ directory of the
calcurse source tree.
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 a new snapshot.
Note: Since calcurse does not use unique identifiers for items, it cannot keep track of moved/edited items. Thus, modifying an item is equivalent to deleting the old item and creating a new one.
calcurse-caldav also has support for services requiring OAuth2 authentication such as Google Calendar. Note that you can only have a single calendar synced at any given time, regardless of authentication method. To enable OAuth2 you will need to:
Change AuthMethod from "basic" to "oauth2" in your config file
Fill in the appropriate settings in your config file: "ClientID", "ClientSecret", "Scope", and "RedirectURI". These can be obtained from the API provider. (See below for Google Calendar)
Install oauth2client for Python 3 using pip (e.g.
pip3 install --user oauth2client) or your distribution’s package manager
Synchronization With Google Calendar
You will need to use your Google account to create a Google API project and enable both the CalDAV API and the Google Calendar API. We will be doing this to receive a Client ID and Client Secret. The hostname, path, scope and redirect URI are listed below.
First, you will need to go to the [Google Developers Console](https://console.developers.google.com/project) and click Create Project. After doing that, you can go to the [API Library](https://console.developers.google.com/project/_/apiui/apis/library) and search for the CalDAV API and enable it for your project. You will then need to do the same for the Google Calendar API.
Next, go to the [Credentials page](https://console.developers.google.com/project/_/apiui/credential) , click on Create credentials, and choose OAuth client ID. If it asks you to "set a product name on the consent screen", click on Configure consent screen to do so. Any product name will do. Upon saving and returning to the "Create client ID" screen, choose Other as the Application type and click Create. You now have your Client ID and Client Secret to put into your calcurse-caldav config file!
The following options should also be changed in your config file:
Hostname = apidata.googleusercontent.com Path = /caldav/v2/*your_calendar_id_here*/events/ Scope = https://www.googleapis.com/auth/calendar SyncFilter = cal
Your Calendar ID for "Path" should be your email for the default calendar. If you have multiple calendars, you can get the Calendar ID by going under Calendar Details at [calendar.google.com](https://calendar.google.com). The default Redirect URI in the config file is http://127.0.0.1; this should work fine, but can be changed to http://localhost, a local web server, or another device if you encounter errors related to it.
A complete config file for firstname.lastname@example.org would have the following options:
[General] ... Hostname = apidata.googleusercontent.com Path = /email@example.com/events/ AuthMethod = oauth2 SyncFilter = cal ... [OAuth2] ClientID = 22802342jlkjlksjdlfkjq1htpvbcn.apps.googleusercontent.com ClientSecret = XPYGqHFsfF343GwJeOGiUi Scope = https://www.googleapis.com/auth/calendar RedirectURI = http://127.0.0.1
[The full guide from Google can be found here.](https://developers.google.com/google-apps/calendar/caldav/v2/guide)
Upon your first run with the
--init flag, you will be asked to go to a URL to
log in and authorize synchronization with your Google account. You can access
this URL on any other device if you cannot open a browser locally (e.g., on
a headless server). Once you authorize synchronization, you will be redirected
to your Redirect URI with a code attached to the end, e.g.,
http://127.0.0.1/?code=4/Ok6mBNW2nppfIwyL-Q1ZPVkEk3zZdZN3mHcY#. You will need
to copy the code after
http://127.0.0.1/?code=. In this case, it would be
Finally pass this authorization code to calcurse-caldav with the
flag and initialize the synchronization database like so (note that the quotes
around the authorization code might be necessary or not, depending on your shell):
calcurse-caldav --init keep-remote --authcode '4/Ok6mBNW2nppfIwyL-Q1ZPVkEk3zZdZN3mHcY#'