Changes to the way HTTPPost works in ElastAlert

[Shashankft9]

Hey, currently when alert type is chosen to be post in the rule as alert: post, elastalert sends an alert to the url using HTTP protocol which makes sense, but I have been recently using something called CloudEvents, which is basically a specification for sending events (alerts) for an event driven architecture:
https://cloudevents.io/
https://github.com/cloudevents/spec/blob/v1.0/spec.md

Would it make sense to incorporate this specification here in http post alert type? This wouldnt change the request headers, but data will be changed as per the spec, basically it will contain the complete cloudevent with its attributes, something like this:

{
  "specversion": "1.0",
  "id": "6fae8d75-97b2-4b13-84b1-9d3a112e1b7b",
  "source": "ElastAlert",
  "type": "com.elastalert.esrule.matched",
  "datacontenttype": "application/json",
  "time": "2021-04-23T13:47:44.283995+00:00",
  "data": "<original_matched_data>",
}

It would be easier to consume these cloudevents wherever you are sending the alert, for example if its a consumer based on golang, you can use this: https://github.com/cloudevents/sdk-go/blob/main/samples/http/receiver/main.go

Code change would have to be done here: https://github.com/jertel/elastalert/blob/alt/elastalert/alerts.py#L1884

Would love to get opinions from people who are using Post as alert type.

[jertel]

This might make sense as a new "CloudEvent" alerter rather than increasing the complexity of the POST alerter. I'm interested in others' thoughts on it.