Consider restricting FlagSourceConfiguration CRD

[Kavindu-Dodan]

Pre-requisites:

• Introduce v1beta1 API version #529
• [FEATURE] Support v1beta1 API of OFO flagd#983
• Use of v1beta1 in OFO logic #531

This issue was derived from comment #514 (comment)

OpenFeature operator supports configurability of flagd sidecar image & tag through two options,

• As startup arguments of the operator (using helm/K8s yaml) ¹
• Using FlagSourceConfiguration's image & tag override options ²

The latter has a potential security impact as the side-car injection can be controlled based on the CRD definition of the respective deployment.

Solution

For a given operator deployment, it is best to fix the sidecar image & tag and disallow any other overloading options. This means, keeping the Operator startup option and removing the option provided through FlagSourceConfiguration crd.

Discussion

Consider following when doing this,

• This is best done with beta version of the Operator API [research] Consider moving CRDs to beta, and making beta "hub" versions #352
• Consider migration path, warnings and test implementation impact

Footnotes

1. https://github.com/open-feature/open-feature-operator/blob/v0.2.35/main.go?rgh-link-date=2023-08-03T18%3A11%3A45Z#L93-L109 ↩

2. https://github.com/open-feature/open-feature-operator/blob/v0.2.35/docs/flag_source_configuration.md#sidecar-configurations ↩

[odubajDT]

The configurability of the flagd sidecar via startup arguments (image & tag) is not part of the implementation yet and needs to be implemented separately. I would probably consider implementing this properly with tests after the implementation of v1beta1 is merged (but definitely before it's released, so we do not have breaking changes). WDYT @Kavindu-Dodan @toddbaert ?

[Kavindu-Dodan]

@odubajDT Actually this is already there but hidden inside a configuration loader ¹ and not well document

Going forward we should only allow this configuration loading (+ document this behaviour) and disallow change through CRD

Footnotes

1. • https://github.com/open-feature/open-feature-operator/blob/v0.2.35/controllers/common/flagd-proxy.go#L68-L75
   ↩

[odubajDT]

@odubajDT Actually this is already there but hidden inside a configuration loader 1 and not well document

Going forward we should only allow this configuration loading (+ document this behaviour) and disallow change through CRD

Footnotes

1. * https://github.com/open-feature/open-feature-operator/blob/v0.2.35/controllers/common/flagd-proxy.go#L68-L75
   
   [↩](#user-content-fnref-1-51f87aad3da9155b04a47936f7360f75)

If I am correct, this is an image + tag for the flagd-proxy, but not for the flagd sidecar, I guess we want the same behavior here