[RFC] Custom Event Metadata from Annotations

[matheuscscp]

No description provided.

[moritzschmitz-oviva]

This is great! Thanks again for picking this up, @matheuscscp 🎉 !

I have nothing to add. It explains the use case very well.

Regarding the API group, I don't know enough about the benefits of implementing the EventRecorder interface. Otherwise, your first suggestion looks sufficient.

[stefanprodan]

LGTM

Thanks @matheuscscp 🏅

[darkowlzz]

I think we should summarize this instead of listing the possible options. Just stating the finalized API group and mentioning about the EventRecorder interface should be good enough.
If this, now finalized, API group is mentioned from the beginning of the RFC, in the summary and proposal, the alternative notification.toolkit.fluxcd.io could be included in the alternatives section. If we do that, we don't need to introduce the API group in design details section and instead focus on elaborating how we'll add it using the EventRecorder interface.

[darkowlzz]

The phrase "sending annotation keys" got my attention here and it feels a little confusing even after considering the rest of the RFC as we don't get into more details to highlight the importance of the metadata prefix which are specific to how the notification-controller event server interprets the received events. This is also phrased similarly in the proposal section. I think what's sent between controllers is an implementation detail that can be elaborated briefly in the design details section. In summary and proposal, I believe we are proposing a solution from a Flux user's perspective and from their perspective, they set annotations with a specific prefix. It may be better to rephrase accordingly and mention about the events, their annotation keys and how it'll be received by the notification-controller event server in the design details.

[darkowlzz]

In case it's not obvious for readers who are not familiar with image-automation-controller, it may help to mention briefly above that IAC will update the chart version and the annotation value with the same latest values, which will be propagated by the notification controller. Just slight details.

[stefanprodan]

Suggested change

	apiVersion: helm.toolkit.fluxcd.io/v2
	kind: HelmRelease
	metadata:
	name: podinfo
	namespace: flux-system
	annotations:
	event.toolkit.fluxcd.io/image: ghcr.io/stefanprodan/podinfo # {"$imagepolicy": "flux-system:podinfo:name"}
	event.toolkit.fluxcd.io/imageTag: 6.5.0 # {"$imagepolicy": "flux-system:podinfo:tag"}
	spec:
	chart:
	spec:
	chart: podinfo
	version: 6.5.0 # {"$imagepolicy": "flux-system:podinfo:tag"}
	sourceRef:
	kind: HelmRepository
	name: podinfo
	apiVersion: helm.toolkit.fluxcd.io/v2
	kind: HelmRelease
	metadata:
	name: podinfo
	namespace: flux-system
	annotations:
	event.toolkit.fluxcd.io/image: latest # {"$imagepolicy": "flux-system:podinfo"}
	spec:
	chart:
	spec:
	chart: podinfo
	sourceRef:
	kind: HelmRepository
	name: podinfo
	values:
	image:
	tag: latest # {"$imagepolicy": "flux-system:podinfo:tag"}

[stefanprodan]

Please replace FluxCD with Flux everywhere.