Target Mark(un)Healthy broken on 3.x

[rainest]

The 2.x and 3.x target endpoints are mutually incompatible after https://github.com/Kong/kong/pull/8596/files. There are no options to for a single piece of code that supports both, even if we drop support for older 2.x versions, as there are no 2.x releases that support PUT.

This requires either version-dependent code within the function or separate 2.x and 3.x functions. AFAIK we have no existing pattern for this in go-kong, as other version-dependent behavior is not part of the API (or is limited to fields that only exist in newer versions, which can coexist fine in the schemas) and delegated downstream.

[AnmolSidhu16]

@pmalek we're in the process of upgrading kong to 3 latest which requires patch for target update admin APIs. Code here still supports only post. any update here?? Thanks in advance.

[pmalek]

No update unfortunately.

As far as I can tell, we can easily introduce version dependent code by checking the version in NewClient() via .Info service and then use that in TargetService.

The problem is that as far as I can see one can mark the target ready in dbless via https://docs.konghq.com/gateway/latest/admin-api/#set-target-as-healthy but I can't see an option to create one. There's only https://docs.konghq.com/gateway/latest/admin-api/#add-upstream which is not compatible with dbless.