fix cloud event flacky unit tests by adding waitgroup

[Yongxuanzhang]

Changes

This commit adds waitgroup to reconciler, so can be used when creating goroutines to send cloud events. waitgroup.Wait() can be called during unit tests to make sure all goroutines are completed and avoid the case that some events are not written into channel before checking. This change shouldn't have influence on current hebaviour since we don't call Wait to block the code. This should be able to fix flacky cloud event tests and we don't have to add time.sleep() before collecting events.

Signed-off-by: Yongxuan Zhang [email protected]

/kind flake

related issues:
#5160
to reproduce this issue, adding time.Sleep() to

pipeline/pkg/reconciler/events/cloudevent/cloudeventsfakeclient.go

Line 53 in b648a5b

func (c FakeClient) Send(ctx context.Context, event cloudevents.Event) protocol.Result {

related PR:
#5313
Recent failing tests:

• https://prow.tekton.dev/view/gs/tekton-prow/pr-logs/pull/tektoncd_pipeline/5666/pull-tekton-pipeline-unit-tests/1582795530906374144
• https://prow.tekton.dev/view/gs/tekton-prow/pr-logs/pull/tektoncd_pipeline/5662/pull-tekton-pipeline-unit-tests/1583441668340715520
• https://prow.tekton.dev/view/gs/tekton-prow/pr-logs/pull/tektoncd_pipeline/5647/pull-tekton-pipeline-unit-tests/1583130831700889600

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Release Notes

Fix cloud event flacky unit tests by adding waitgroup

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[Yongxuanzhang]

cc @lbernick @abayer

[vdemeester]

/cc @afrittoli

[Yongxuanzhang]

This is one approach we may use to fix the cloud event flacky test. Please take a look 🙏

[Yongxuanzhang]

/hold for more reviews

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/reconciler/events/cloudevent/cloud_event_controller.go	88.2%	88.6%	0.3

[lbernick]

Chatting with @Yongxuanzhang, he is exploring an alternative solution where more of the waitgroup logic is contained to the events/cloudevents packages. I think it would be preferable for the events/cloudevents fakes to be able to test events by waiting until all of them are done being sent, but if that solution doesn't work out, this will be a great fix to have in!

[tekton-robot]

The following Tekton test failed:

Test name	Commit	Details	Required	Rerun command
check-pr-has-kind-label	70fcf0e	link	true	/test check-pr-has-kind-label

[Yongxuanzhang]

we may want to use #5690