'In Terraform, how do I repeat a dynamic block by an integer count?

I need to add multiple scratch_disk clauses to a resource for a Google Cloud VM.

I can use the following...

resource ... {
  dynamic "scratch_disk" {
    for_each = var.scratch_disk_count
    content {
      interface = "SCSI"
    }
  }
}

but then var.scratch_disk_count needs to be [ 1, 2, 3, 4 ] which looks a bit silly.

I tried replacing for_each with count = 4 but terraform said it didn't expect count there.

Is there a function to produce [ 1, 2, 3, 4 ] from 4, or just some generally better way?

This is a simple characterisation of the problem - I understand I could have the list be [ "SCSI", "SCSI", "NVME" ] or similar.

Thanks.

for-loopterraform


Solution 1:[1]

Yes you can use the range function for this:

resource ... {
  dynamic "scratch_disk" {
    for_each = range(var.scratch_disk_count)
    content {
      interface = "SCSI"
    }
  }
}

In your example above where the value of var.scratch_disk_count is 4, then the return of the range function will be [0, 1, 2, 3], and will produce the desired behavior. Note that it is also common to use the range function in dynamic blocks in this manner.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 Matt Schuchard

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