How count.index works

Terraform Providers Plugin Development
2

Hey there @OrNovo :wave: thanks for posting and sorry you’re running into trouble here,

Addressing the error

Based on that error message, I’m assuming that you have a data model that looks something like:

type ResourceModel struct {
	// other `tfsdk` fields
	Applications       *coralogix.TCORuleModel `tfsdk:"applications"`
}

type TCORuleModel struct {
	// other `tfsdk` fields
}

The error you’re running into is a result of Go structs not having a concept of Unknown, so when plugin framework receives an Unknown value from Terraform core, it returns a diagnostic because it can’t convert Unknown into the TCORuleModel struct. The fix would be to switch to the plugin framework types.Object type:

type ResourceModel struct {
	// other `tfsdk` fields
	Applications        types.Object `tfsdk:"applications"`
}

type TCORuleModel struct {
	// other `tfsdk` fields
}

You can see some examples of accessing/setting types.Object values in our recently revamped documentation:

Terraform Core behavior

I don’t have a background on why Terraform core considers the local.test[count.index] expression as unknown, regardless, our recommendation is to always use the built-in framework types to stay in-line with Terraforms type system concepts.

Perhaps @jbardin or someone from the Terraform core team could expand on why that expression is unknown.

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