asciipip / ical2gcal

Pull events from an iCalendar feed into a Google Calendar

ical2gcal

Takes entries from an iCalendar feed and puts them into a Google Calendar.

This is semantically a little different from simply adding the iCalendar feed to Google Calendar, in that it merges the iCalendar feed's entries into an existing calendar rather than having them presented as a separate calendar in the Google Calendar interface.

Needs Python Packages

• googleapi https://github.com/google/google-api-python-client
• httplib2 https://github.com/jcgregorio/httplib2
• icalendar http://icalendar.readthedocs.org/
• requests http://docs.python-requests.org/
• toml https://github.com/uiri/toml

Setting Up Permissions

This program is intended to run without user interaction, so it operates under the Google API's "server-to-server" model using a service account. Unfortunately, that means the initial authorization process is a little involved.

Follow Google's service account instructions to get a private key for the application:

1. Open the Google Developer Credentials Page.
2. Log in with your Google account, if necessary.
3. Create a new project. Give it a useful name (e.g. "ical2gcal").
4. Continue to your new project.
5. Click on the "Enable the APIs you want to use" link, find the Calendar API, and enable it.
6. After enabling the Calendar API, click on the "Go to Credentials" button. In the text at the top of that page, there will be a link to create a service account. Click on that link.
7. Click "Create service account".
8. Give the account a name and ID. Make a note of the ID.
9. Check "Furnish a new private key". Change the key type to P12. (The recommended JSON format should work with relatively recent versions of the Python library, but only P12 has been tested.)
10. Click "Create".
11. Save the file it sends you and click "Close".

Next, you need to grant the service account access to your Google Calendar:

1. In Google Calendar, hover over the calendar in the "My calendars" list and click the down arrow that appears to the right of the calendar name. Click "Calendar settings".
2. Make a note of the Calendar ID in the "Calendar Address" section of the page. You'll need this later.
3. Click the "Share this Calendar" tab.
4. Enter the service account ID into the blank Person space. Change the permission settings to "Make changes to events".
5. Click the "Add Person" button.
6. Click the "Save" button.

The Config File

The config file is a TOML config file. The google_calendar_id, google_client_email, private_key_file, and icalendar_feed settings are mandatory; if they're not present in the config file, you need to provide them on the command line.

The settings are:

• google_calendar_id - The ID of the calendar you're adding events to. Should be something like "[e-mail]".
• google_client_email - The service account ID.
• private_key_file - The file you downloaded with your service account's private key.
• private_key_password - The password for the private key file, if you changed it. If you don't provide this setting, the program will use "notasecret", Google's default password. (Unless you're being surprisingly paranoid with your setup, changing the password won't make things any more secure.)
• icalendar_feed - The URL of the iCalendar feed to pull from.
• include_categories - An array of event categories to sync. If present, an event belonging to at least one of the given categories will be synced. If absent (or empty), all events will be synced.
• exclude_categories - An array of categories to exclude. If an event belongs to any of the given categories it will not be synced, regardless of the value of include_categories

There's an example config file named ical2gcalrc.sample that shows the syntax needed.