## The symptom
With the IBM Cloud Terraform provider, `data "ibm_container_vpc_cluster"`
looked up by ID returns the cluster ID (not the name) from the `.name`
attribute, and the deprecated `cluster_name_id` field returns null. You need
the actual cluster name in config.
## Do not do this
The reporter resorted to parsing the name out of the ingress hostname with a
regex. It is fragile and undocumented; do not copy that approach.
## The fix
The data source exposes the actual name via other attributes:
- `cluster_name`: the officially supported attribute, added on both the cluster
and vpc_cluster data sources (a maintainer closed the issue as fixed with
that addition).
- `resource_name`: an undocumented field a community member found, confirmed
working by the reporter.
If your config uses `data.ibm_container_vpc_cluster.cluster.name` expecting a
name, switch it to `cluster_name` (or `resource_name` on older provider
versions that predate `cluster_name`).
## The general lesson
When a data source attribute returns something surprising (an ID instead of a
name), check for sibling attributes before regex-parsing derived values. The
right field often exists under a different name.