feat: add signal for event-tracking emission

[Ian2012]

Description: This PR defines a signal that listens to every event-tracking emission event. It's currently needed to emit events via the event bus to the OARS stack to have real-time events and better performance than the current implementation.

ISSUE: #215

Dependencies: None

Testing instructions: More details in openedx/event-tracking#246

Merge deadline: This is needed for the Aspects project to move the tracking log processing from celery to async processing, more details in this PR openedx/event-routing-backends#361

Reviewers:

Merge checklist:

• All reviewers approved
• CI build is green
• Version bumped
• Changelog record added
• Documentation updated (not only docstrings)
• Commits are squashed

Post merge:

• Create a tag
• Check new version is pushed to PyPI after tag-triggered build is
  finished.
• Delete working branch (if not needed anymore)

[openedx-webhooks]

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[mariajgrimaldi]

Please, add a bit more info in the cover letter! Like how to test, the need for the event, etc. So the community knows how important it is :)

[bmtcril]

This is also blocked on #224 and its implementation

[Ian2012]

@bmtcril why is it blocked by that PR?

I was thinking that this feature flag would prevent performance issues on large installations:

https://github.com/openedx/event-routing-backends/pull/305/files#diff-475f912f3206aed7a6cbb4ac6a1954040e433ff426ce93f798c2700558e34d88R14

Or am I missing something?

[mariajgrimaldi]

Hi! is this ready for our review? If it's not, then please convert it to draft :)! thanks

[bmtcril]

I think we should flip this to draft and round up on the process some more. I'm confused why the producer is in event-routing-backends and not event-tracking, and want to make sure we both understand how it's all supposed to be working together

[mphilbrick211]

Hi @bmtcril and @mariajgrimaldi - just checking in on this :)

[bmtcril]

I think this work is punted to Aspects v2 unless someone picks it up first. I can close it for now, but would prefer to leave it in draft if we can.

[Ian2012]

As the event bus doesn't support dictionaries we are sending a JSON string version of the context and the extra data. It's expected that the event bus consumer to handle this information

[Ian2012]

@bmtcril @mariajgrimaldi this is ready for review now

[bmtcril]

This makes sense to me. When we get to the epic task of updating tracking logs to formalize them I hope we can revisit the dictionary issue, but I think this will get the job done. I'm not a committer here so I won't thumb it, but lgtm.

[mariajgrimaldi]

I'll be reviewing this. Thanks!

[mariajgrimaldi]

I left a few comments for you folks to review!

[mariajgrimaldi]

LGTM! Thank you folks

[mphilbrick211]

Hi @mariajgrimaldi! Are you able to merge this?

[mphilbrick211]

Hi @mariajgrimaldi! Are you able to merge this?

@bmtcril - is this something you can merge if Maria is unable?

[mariajgrimaldi]

@mphilbrick211: I was waiting for Cristhian to update the init file. I'll be merging this now.

[openedx-webhooks]

@Ian2012 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.

[mphilbrick211]

Sorry about that, @mariajgrimaldi - thank you!