Extend yaml2ical to add one-off events and merged calendars

[dagwieers]

So we would like to have the following functionality in yaml2ical:

• For Sprints or other special events (e.g. AnsibleFest etc.) it would be nice to be able to have one-off events, currently yaml2ical only supports recurring events (with weekly or bi-weekly frequency)

• It would be nice if we could still generate one single calendar including all individual calendars and one-off events. This way we could have one single calendar for all Ansible-related events, in addition to the individual calendars.

[gregdek]

From a quick look, it seems like there's a new "ad-hoc" option that may be worth looking at, committed in August:

openstack-infra/yaml2ical@f2f9828

[gregdek]

If I understand correctly, this addition means we could theoretically:

• put all one-off events in a single file, "one-off.yaml" or similar
• add a new "master.ics" file that is the "full calendar"
• have some kind of script that runs on checkin to any .yaml file in meetings/
  • rebuild the corresponding .ics file
  • re-run full aggregation of all .yaml files and rebuild the master.ics file

It seems like the new yaml2ical should support this workflow.

[mattclay]

If we have a command such as make update to rebuild the calendar files, we can then add a Shippable check to make sure it doesn't make any changes on a PR. If changes are detected, it can provide a helpful message stating that you need to run make update (or whatever) as part of your PR.