Feature/eventbridge v2 add input transformer

[maxhoheiser]

Motivation

This PR adds input transformers https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-transform-target-input.html to the v2 provider. Input transformers use either predefined placeholders or custom placeholders defined in input template or a combination of both, that are used to re-write the returned event.
Predefined placeholders can return either a string or a dict ( dicts are only allowed in json input maps)

The event that is returned is the input map that gets populated with the placeholders described before with the variables from the original event and rule. The input map can be either a plain string or a json string that results in a return dict.

Changes

Add input transformer to transform incoming event based on input path and input map.
Add predefined placeholders.
Add tests for input path string and json.
Add test for predefined placeholders.
Add test for combining input path and input transfomrer.

[github-actions]

LocalStack Community integration with Pro

    2 files  ±0      2 suites  ±0   1h 36m 50s ⏱️ +51s
2 941 tests +6  2 640 ✅ +1  301 💤 +5  0 ❌ ±0 
2 943 runs  +6  2 640 ✅ +1  303 💤 +5  0 ❌ ±0 

Results for commit ab05337. ± Comparison against base commit e69d60f.

This pull request removes 6 and adds 12 tests. Note that renamed tests count towards both.

tests.aws.services.events.test_events_inputs.TestEventsInputPath ‑ test_put_events_with_input_path
tests.aws.services.events.test_events_inputs.TestEventsInputPath ‑ test_put_events_with_input_path_max_level_depth
tests.aws.services.events.test_events_inputs.TestEventsInputPath ‑ test_put_events_with_input_path_multiple_targets
tests.aws.services.events.test_events_inputs.TestEventsInputPath ‑ test_put_events_with_input_path_nested[event_detail0]
tests.aws.services.events.test_events_inputs.TestEventsInputPath ‑ test_put_events_with_input_path_nested[event_detail1]
tests.aws.services.events.test_events_inputs.TestEventsInputTransformers ‑ test_put_events_with_input_transformation_to_sqs

tests.aws.services.events.test_events_inputs ‑ test_put_event_input_path_and_input_transfomer
tests.aws.services.events.test_events_inputs.TestInputPath ‑ test_put_events_with_input_path
tests.aws.services.events.test_events_inputs.TestInputPath ‑ test_put_events_with_input_path_max_level_depth
tests.aws.services.events.test_events_inputs.TestInputPath ‑ test_put_events_with_input_path_multiple_targets
tests.aws.services.events.test_events_inputs.TestInputPath ‑ test_put_events_with_input_path_nested[event_detail0]
tests.aws.services.events.test_events_inputs.TestInputPath ‑ test_put_events_with_input_path_nested[event_detail1]
tests.aws.services.events.test_events_inputs.TestInputTransformer ‑ test_input_transformer_predefined_variables["Message containing all pre defined variables <aws.events.rule-arn> <aws.events.rule-name> <aws.events.event.ingestion-time>"]
tests.aws.services.events.test_events_inputs.TestInputTransformer ‑ test_input_transformer_predefined_variables[{"originalEvent": <aws.events.event>, "originalEventJson": <aws.events.event.json>}]
tests.aws.services.events.test_events_inputs.TestInputTransformer ‑ test_put_events_with_input_transformer_input_template_json
tests.aws.services.events.test_events_inputs.TestInputTransformer ‑ test_put_events_with_input_transformer_input_template_string["Event of <detail-type> type, at time <timestamp>, info extracted from detail <command>"]
…

♻️ This comment has been updated with latest results.

[joe4dev]

LGTM overall 👍
Looking forward to reusing this input transformer in Pipes as well in the future 🚀

I commented regarding a couple of edge cases, which would be nice to fix or validate.

[joe4dev]

Would it make sense to test this assumption? For example: {<aws.events.rule-name> works?

[maxhoheiser]

extended test in: ab05337

[joe4dev]

The split won't work if the name contains a slash /, which is a valid character according to this regex: (arn:aws[\w-]*:events:[a-z]{2}-[a-z]+-[\w-]+:[0-9]{12}:event-bus\/)?[/\.\-_A-Za-z0-9]+
https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_PutRule.html#eventbridge-PutRule-request-EventBusName
See regex example: https://regex101.com/r/aNQ4KF/1

Maybe parse_arn would be more reliable here?

[maxhoheiser]

pars_arn did not work, since it only returns the resource that contains bus and rule name and as you pointed out both bus and rule name can have /. I added rule_name as a TargetSender instance variable.
Fixed in: 1b0366d

[joe4dev]

How are non-string values such as the discussed integer scenario work now?

[maxhoheiser]

I don't deal with this one edge case for for the predefined placeholder <aws.events.events> where the event body contains "time" which is returned as an int, not a string. I figure that this is such an edge case that we can deal with it once we have the provider at parity.

[joe4dev]

Fair point 👍
Let's keep track of it somewhere for the future.

[joe4dev]

Can this fail with an invalid jsonpath?

[maxhoheiser]

the boto client validation of input template that checks that only placeholders that are using a json path that is present in the defined event should handle errors long before extract_jsonpath will be called, therefore it should be save.