Bug: MySQL Flexible Server property sourceServerResourceId has wrong type

[theunrepentantgeek]

While responding to a question on Slack, I spotted the property FlexibleServer sourceServerResourceId which looks to be an ARM resource ID, and therefore should be a genruntime.ResourceReference not a string.

We can't really change the existing version, but I think we should import the latest version(s) of the API (2023-06-30 and maybe 2023-10-01-Preview) and change it there.

[matthchr]

We should investigate how the heuristic missed this, and see if we can improve it - for example looking for properties that end in "resourceId" as I don't think it's doing that

[theunrepentantgeek]

Trying out some improvements to our heuristic and finding other properties we missed:

Group	Version	Kind	Property
authorization	v1api20200801preview	RoleAssignmentProperties	DelegatedManagedIdentityResourceId
authorization	v1api20220401	RoleAssignmentProperties	DelegatedManagedIdentityResourceId
dbformysql	v1api20210501	ServerProperties	SourceServerResourceId
machinelearningservices	v1api20210701	IdentityForCmk	UserAssignedIdentity
machinelearningservices	v1api20210701	KeyVaultProperties	KeyVaultArmId

We need to decide whether fixing these is important enough to have a breaking change, or whether we can do so without breaking.

[theunrepentantgeek]

We could make this less of a breaking change if we modified genruntime.ResourceReference to allow deserialization from a plain string. We then wouldn't break existing resources, so in-place upgrades of ASO in an existing cluster would work fine. Users would still need to modify their resources to apply them though.

[matthchr]

We could make this less of a breaking change if we modified genruntime.ResourceReference to allow deserialization from a plain string. We then wouldn't break existing resources, so in-place upgrades of ASO in an existing cluster would work fine. Users would still need to modify their resources to apply them though.

I think we've looked into this in the past and determined that it won't work because of Kubernetes structured schema requirements, specifically that they won't let you model that in the Swagger so even if the underlying Go type can do it, APIServer will (I believe) reject the request because it doesn't match the OpenAPI spec.

[matthchr]

Synced up and decided to first check what new apiversions for these resource types are supported - possibly we can fix there in a totally nonbreaking way.

[theunrepentantgeek]

For the three identified groups, the latest available versions are:

Group	Stable	Preview
authorization	2022-04-01	2020-10-01-preview
dbformysql	2023-06-30	2023-10-01-preview
machinelearningservices	2023-10-01	2023-08-01-preview