Support Service Account Authentication #859
Description
Problem
Running gcalcli on headless servers (e.g., for CI/CD notification, backup scripts) is operationally painful. It relies on user-centric OAuth2 flows requiring a browser redirect or manual token copy-paste. Access tokens expire, leading to pipeline failures when refresh tokens are revoked or invalidated, creating unnecessary maintenance alerts.
Solution
Implement Service Account authentication support.
- Flag:
--service-account <path/to/key.json>. - Headless Auth: Authenticate directly using Google Cloud Service Account credentials, removing the need for user interaction.
- Security: Enables the use of least-privilege service accounts scoped specifically to the required calendars, rather than granting full user profile access.