Honoring an optional `spec.channel` field in the `Operator` API.

[joelanford]

This issue should be closed when a demo recording is posted to the #olm-dev kubernetes slack channel that follows the below script:

Demo Script:

1. Install operator-controller from the main branch or its most recently tagged release using operator-controller's standard install script and manifest.
2. Create a Catalog object referencing quay.io/operatorhubio/catalog:latest
3. Show that the catalog status reflects that it was successfully unpacked.
4. Create an Operator object referencing package strimzi-kafka-operator with channel strimzi-0.32.x
5. Show that a BundleDeployment gets created and references the bundle image quay.io/operatorhubio/strimzi-kafka-operator@sha256:0d4ac0ed10d815b30dca6521d3ceab5dfc150cddda22e9ca83e97462dbcfeff4
6. Edit the Operator object and change the channel to strimzi-0.33.x
7. Show that the existing BundleDeployment is updated to reflect a new bundle image reference with quay.io/operatorhubio/strimzi-kafka-operator@sha256:4d953d5fd719ea61a7009daaa7e37c948073132f231c2d2d1b07bf3d0d5d6e3b
8. Edit the Operator object and remove the channel specification.
9. Show that the existing BundleDeployment is updated to reflect a new bundle image reference with the highest semver bundle defined in the package (as of 4/5/23, that version is 0.34.0): quay.io/operatorhubio/strimzi-kafka-operator@sha256:42a3dce711492fae22f2d919299a0594f152396f6c2fef65ffc47226ba9c786e
10. Edit the Operator object and set the channel to foobar.
11. Show the the Operator object has its status updated to reflect that no version is available in the specified channel. Also show that the BundleDeployment is still present and remains at version 0.34.0.
12. Delete the Operator objects.

Related Issues:

• Introduce spec.channel field to the operator API #169
• Operator-Controller resolution considers spec.channel #170

[tmshort]

Demo added to slack channel: https://kubernetes.slack.com/archives/C0181L6JYQ2/p1682347015950669

[pgodowski]

I know perhaps it's wrong place to ask the question, but let me ask anyway: What is the semantics in OLM v1 of the channel concept, in relation to OLM v0?

[joelanford]

@pgodowski - can you start a discussion topic for that question? In general the concept is the same, but the mechanics are up for re-evaluation in OLMv1. I suspect we'll need to dive down into specific aspects of what you're trying to understand.

[joelanford]

I think we can call this one finished. In addition to the slack channel post, we demoed this at yesterday's WG meeting. Thanks to all involved!