Template_file and metadata_startup_script variables not working as expected

Terraform
1

I have gce resource being created and bootstrapped with a startup script but seeing some weird issues with variables.
Created TF resources as per:

data "template_file" "init" {
  template = "${file("../../../Boomi/linux/test.sh")}"
  vars = {
    platform            = var.platform
  }
}

resource "google_compute_instance" "atom_instance" {
  machine_type = var.machine_type
  metadata_startup_script = "${data.template_file.init.rendered}"
...
test.sh script
#!/bin/bash
#set -e
echo "platform:${platform}"
if [ -z $platform ] ; then
  echo "parameter needed!"
if [ -n $platform ] ; then
  echo "parameter provided!"
fi
echo "completed"

In the Serial Console output I got the following after the bash script was run:

Jan 15 20:44:25 debian google_metadata_script_runner[471]: startup-script: platform:gcp
Jan 15 20:44:25 debian google_metadata_script_runner[471]: startup-script: parameter needed!
Jan 15 20:44:25 debian google_metadata_script_runner[471]: startup-script: parameter provided!
Jan 15 20:44:25 debian google_metadata_script_runner[471]: startup-script: completed
Jan 15 20:44:25 debian google_metadata_script_runner[471]: startup-script exit status 0

This makes no sense as $platform variable is set so wouldn’t expect “parameter needed!” in the output.
It seems like the null check is not working?
if [ -z $platform ] ; then
Any ideas?

2

Issue has been resolved.
Was related to how I was using variables, required curly brackets ${var}.

3

what’s the version of terraform? I think the behavior is related to the version.