Terraform Validate Does Not Warn On Interpolation In Lists

[rbradley-novetta]

Terraform Version

Terraform v0.12.28 and 0.13.3

Terraform Configuration Files

Debug Output

Crash Output

no crash

Expected Behavior

terraform validate should raise a warning for deprecated string interpolation inside lists

Actual Behavior

Running terraform validate against the following does not return a warning when interpolation is used inside a list:

locals {
  network = "network"
  range = "192.168.0.0/24"
}
provider "google" {
}
resource "google_compute_network" "network" {
  name = local.network
  auto_create_subnetworks = "false"
}
resource "google_compute_subnetwork" "subnetwork" {
  depends_on = [google_compute_network.network]
  name = "subnetwork"
  network = local.network
  ip_cidr_range = local.range
}
resource "google_compute_firewall" "firewall" {
  depends_on = [google_compute_network.network]
  source_ranges = ["${local.range}"]
  name = "firewall"
  network = local.network
  allow {
    protocol = "udp"
  }
}

But it does if interpolation is used in a lone string:

resource "google_compute_network" "network" {
  name = "${local.network}"
  auto_create_subnetworks = "false"
}

Steps to Reproduce

1. terraform init
2. terraform validate

Additional Context

References

[alisdair]

Thanks for reporting this! I can confirm this behaviour exists in 0.13 and 0.14.

We recently added more interpolation deprecations in #26105, but nested expressions are not included in that change. I believe that is a reasonable thing to expect to be validated, especially since we're being more strict with these deprecations in the next 0.13 release.

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.