Add support for message-batch (v2) payloads

[andrewlock]

Description

Add support for v2 telemetry message-batch payloads by "flattening" the batch into multiple requests. Not all tests require this, but many do.

Motivation

The telemetry tests commonly assert for particular message types, but when you use message-batch, the messages are nested inside the payload. So instead of this:

{
  "request": {
    "content": {
      "api_version": "v1",
      "request_type": "app-started",
      "payload": {}
    }
  }
},
{
  "request": {
    "content": {
      "api_version": "v1",
      "request_type": "app-dependencies-loaded",
      "payload": {}
    }
  }

you have something like this:

{
  "request": {
    "content": {
      "api_version": "v2",
      "request_type": "message-batch",
      "payload": [
        {
          "request_type": "app-started",
          "payload": {}
        },
        {
          "request_type": "app-dependencies-loaded",
          "payload": {}
        }
      ]
    }
  }
}

To handle that, added an extra helper function. As well as get_telemetry_data() there's now also get_flattened_telemetry_data()

Workflow

1. ⚠️⚠️ Create your PR as draft
2. Follow the style guidelines of this project (See how to easily lint the code)
3. Work on you PR until the CI passes (if something not related to your task is failing, you can ignore it)
4. Mark it as ready for review

Once your PR is reviewed, you can merge it! ❤️

Reviewer checklist

• If this PR modifies anything else than strictly the default scenario, then add the run-all-scenarios label (more info).
• CI is green
  • If not, failing jobs are not related to this change (and you are 100% sure about this statement)
• if any of build-some-image label is present
  1. is the image labl have been updated ?
  2. just before merging, locally build and push the image to hub.docker.com

[cbeauchesne]

IIUC, we want to keep all test logics used in get_telemetry_data applied on sub-payloads if request_type == "message-batch".

What about using the same function, but with an optional argument, set by default to True ?

get_telemetry_data(self, flatten_message_batches=True) ?

[andrewlock]

IIUC, we want to keep all test logics used in get_telemetry_data applied on sub-payloads

Yes, in most cases. There are some cases (where we're operating at the "request" level rather than the "payload" level) where we don't want that logic though, hence adding this additional method.

What about using the same function, but with an optional argument, set by default to True

Yep, that works for me 🙂 I'll update to that approach instead 👍

Also, I've just realised that telemetry has some explicit additional scenarios, e.g. TELEMETRY_METRIC_GENERATION_DISABLED etc. I assume I should add the run-all-scenarios to this (after making the change)?

Thanks!

[cbeauchesne]

I assume I should add the run-all-scenarios to this (after making the change)?

yep :)

[andrewlock]

Done 🙂 There were some failing tests, but AFAICT they're probably flaky as they don't touch the telemetry stuff. Is it ok to just retry them? (Not sure of norms on this repo yet!)