Remove messaging v1alpha1

[vaikas]

Fixes #

Proposed Changes

• Remove messaging.v1alpha1 APIs

Release Note

- 🗑️ Remove feature or internal logic
action required: messaging.v1alpha1 is being removed, you must migrate to messaging.v1beta1.

Docs
knative/docs#2545

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: vaikas

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [vaikas]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[mattmoor]

Produced via:
gofmt -s -w $(find -path './vendor' -prune -o -path './third_party' -prune -o -type f -name '*.go' -print)

[mattmoor]

Produced via:
gofmt -s -w $(find -path './vendor' -prune -o -path './third_party' -prune -o -type f -name '*.go' -print)

[knative-test-reporter-robot]

The following jobs failed:

Test name	Triggers	Retries
pull-knative-eventing-integration-tests		0/3

Failed non-flaky tests preventing automatic retry of pull-knative-eventing-integration-tests:

test/conformance.TestChannelStatusSubscriber
test/conformance.TestChannelStatus
test/conformance.TestChannelStatus/Channel-messaging.knative.dev/v1beta1
test/conformance.TestChannelStatusSubscriber/Channel-messaging.knative.dev/v1beta1
test/conformance.TestChannelStatusSubscriber/Channel_has_required_status_subscriber_fields#01
test/conformance.TestChannelStatus/Channel_has_required_status_fields#01

[mattmoor]

Produced via:
gofmt -s -w $(find -path './vendor' -prune -o -path './third_party' -prune -o -type f -name '*.go' -print)

[mattmoor]

Format Go code:

Suggested change

	c.Status.Conditions = []apis.Condition{apis.Condition{Type: apis.ConditionReady, Status: corev1.ConditionTrue}}
	c.Status.Conditions = []apis.Condition{{Type: apis.ConditionReady, Status: corev1.ConditionTrue}}

[knative-metrics-robot]

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

File	Old Coverage	New Coverage	Delta
pkg/apis/duck/v1alpha1/register.go	Do not exist	100.0%
pkg/apis/eventing/v1beta1/test_helper.go	68.6%	80.0%	11.4
pkg/apis/messaging/v1beta1/in_memory_channel_defaults.go	0.0%	100.0%	100.0
pkg/reconciler/subscription/subscription.go	85.3%	85.4%	0.1

[grantr]

Just to make sure I understand: We changed storage version of InMemoryChannel, Channel, and Subscription to v1beta1 in #3169 and released that in 0.15. So any cluster that previously upgraded to 0.15 won't have any objects stored in v1alpha1 anymore so this removal is safe (in terms of stored objects).

Seems like we'll need to be clear in release notes that if the cluster is 0.14 or earlier and any of these objects exist, operators must run the 0.15 upgrade job before upgrading to 0.16. Is it also necessary to install 0.15 before running the upgrade job? The 0.15 release notes suggest as much: "Please run the storage migration tool after the upgrade" (emphasis mine).

[vaikas]

Yes, my understanding has been up to this point that we only support +1/-1 release upgrade/downgrade.
So, yes your understanding is correctomundo, is there a particular change that you'd like to make in this PR, or can we tackle the documentation in a follow on PR? I've tried to put in all the PRs action required :)

[n3wscott]

/lgtm

[grantr]

No change requested in this PR, just want to make sure we have a plan for documenting how to upgrade and what are the pitfalls. Seems like you've got it handled 👍