Terraform resource generate multiple key_pair with modules - terraform

Question

I'm trying to utilize terraform modules and am having issues with key creation. I want to generate a new aws_key_pair for each run of my module. I am receiving
aws_key_pair.default: Error import KeyPair: InvalidKeyPair.Duplicate: The keypair 'keyname' already exists.
I would like to generate a new key (with a different name) for each run of the module but am lost as to how to achieve this.
I have in variables.tf
variable "key_pair_name" {
description = "EC2 Key pair name"
default = ""
}
and in resources.tf
resource "key_pair" "default"
key_name = "keyname"
public_key = "${file("${var.key_path}")}"
Which generates the first key fine. When module runs it will try to recreate the same key again which already exists. I want it to create a second, third and so on key named seperately ie: keyname1, keyname2, keyname3 or a random string.
I am trying
resource "random_id" "key_pair_name" {
name = {
key_name = "${random_id.key_name}"
}
byte_length = 8
}
I am starting this off from a simple main.tf
module "one" {
source = "/modules/test-example"

Answer 1

Writting the module
In your variable.tf:
variable "key_pair_names" {
description = "EC2 Key pair names"
default = [
"keyname1",
"keyname2"
]
}
In your resources.tf:
resource "key_pair" "default" {
count = "${length(var.key_pair_names)}"
key_name = "${element(var.key_pair_names, count.index)}"
public_key = "${file("${element(var.key_pair_names, count.index)}")}"
}
NB: the name of the local file needs to be the same than the remote key pair created
To override the variables
If you are running terraform directly in that directory, run:
terraform apply -var-file=terraform.tfvars
With the `terraform.tfvars:
key_pair_names = [
"keyname1",
"keyname2",
"keyname3"
]
If your are using the module from an other main.tf file:
module "key_pair" {
path = "path/to/module"
key_pair_names = [
"keyname1",
"keyname2",
"keyname3"
]
}

Answer 2

If someone else has this problem I was able to solve this using terraform random_id
resource "random_id" "keypair" {
byte_length = 8
}
resource "keypair" "default" {
name = "${random_id.keypair.hex}"

Answer 3

To achieve unique keyname at every run, you can use uuid function in terraform (https://www.terraform.io/docs/configuration/interpolation.html#uuid-)
You can define your codeblock as
resource "key_pair" "default"
key_name = "keyname-${uuid()}"
public_key = "${file("${var.key_path}")}"
But what are you trying to achieve with different keypair against a public key?