Terraform CLI

Terraform requires a specific resource instance key

Error: Missing resource instance key

Terraform cannot access an attribute on a resource that uses for_each or count unless the expression identifies a specific instance or iterates over all instances.

Missing resource instance keyconfiguration

Observed message

Error: Missing resource instance key

Why it happens

A resource created with for_each is being referenced as if it were a single object.
The configuration accesses a count-based or for_each-based resource without an index or key.
Outputs or locals were not updated after converting a resource from single-instance to multiple instances.

How to fix it

Reference a specific instance with the appropriate key or index when you need one object.
Use a for expression if you need a list of values from all created instances.
Update outputs, locals, and downstream references after introducing count or for_each.

Official reference

Troubleshoot Terraform

Related errors

Explore more