WIP: Event/annotation timeline (basically Gantt chart)

I’ve started working on some changes to the Discrete panel that adds support for non-timeseries events coming from a datasource like Elasticsearch. My idea is that this can be used to display annotations that also have a duration (I think there’s a feature request floating around to add that to the graph panel; IMO a separate panel is more flexible).

Here’s an example showing annotations alongside an event timeline, coming from the same datasource. Note that this also supports “ongoing” events, where one or both of the start and end times fall outside the current time range. This did require a bit of hackery in the issueQueries() method that could probably be done better.

Any suggestions or feedback is appreciated. See the pull request for more details.


Looks really nice (and useful)