1137839 - [alerts] add "alert happened on" timestamp

Status: RESOLVED FIXED

(Input Graveyard :: Backend, defect, P1)

Description

[Will Kahn-Greene [:willkg] ET needinfo? me]

We're currently conflating the "created" time (when the Alert record was created) with the "alert happened on" time in the Alerts system and API. This creates several problems: we can't backfill alerts, the emitter needs to post the alert as soon as the event has happened--it can't wait for some period of time later--and we don't account for timezone offsets

This bug covers:

1. adding another required timestamp field to the model

2. figuring out what format the API should require for that field which accounts for timezones

3. establishing how this field will work

4. documenting all that with Python examples

Comment 1

[Will Kahn-Greene [:willkg] ET needinfo? me]

Grabbing this to work on on Monday.

Comment 2

[Will Kahn-Greene [:willkg] ET needinfo? me]

I had a dream where my future self said to name the new field "start" and while I was doing this, to also add an "end" field to allow for alerts that talk about some happenstance over a period of time. My future self said the fate of humanity depends on this!

Comment 3

[Will Kahn-Greene [:willkg] ET needinfo? me]

In PR: https://github.com/mozilla/fjord/pull/506

We're using iso8601 which is pretty standard.

* JavaScript: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString
* Python: https://docs.python.org/2/library/datetime.html#datetime.datetime.isoformat

I didn't add Python examples to the documentation. I'll just send those to Cheng in an email.

Comment 4

[Will Kahn-Greene [:willkg] ET needinfo? me]

Landed in https://github.com/mozilla/fjord/commit/7a604979867adb46ee72c95225bebb9df0b751a0

Pushed this to prod just now.