PingSource sink field is unpopulated on non-storage versions

[vitreuz]

Describe the bug
PingSource is missing "sink" info on the non-storage versions. (v1alpha1, v1beta1)

Expected behavior
Given that both v1alpha1 and v1beta1 are supposed to satisfy the v1 duck type, and their api schemas show the full sink field, I expect them to properly populate the sink field on these non-storage versions.

To Reproduce

1. create a ping source following the first 3 steps of PingSource example docs
2. Run either command:

kubectl get pingsources.v1beta1.sources.knative.dev test-ping-source -n pingsource-example -oyaml

kn source ping describe test-ping-source -n pingsource-example

The spec.sink field is unpopulated.

Knative release version
v0.21.0

[lionelvillard]

@vitreuz the v1beta2 spec is actually stored in the pingsources.sources.knative.dev/v1beta2-spec annotation in v1beta1. I don't recall why this has been done this way, maybe @eclipselu remembers.

[eclipselu]

@vitreuz the v1beta2 spec is actually stored in the pingsources.sources.knative.dev/v1beta2-spec annotation in v1beta1. I don't recall why this has been done this way

it's because v1beta1 was the storage version when v1beta2 was introduced, and v1beta2 has added feature that v1beta1/v1alpha1 do not support, to store a v1beta2 object, it needs to be converted to v1beta1, if we do a straightforward conversion, the added feature in v1beta2 will be lost. So storing the whole v1beta2 spec in annotation is the way we chose to mitigate the issue.

See here

[eclipselu]

/assign @eclipselu

[grantr]

This might miss the 0.22.0 release, but we can get it into a 0.22.x point release.