Terraform launch template - amazon-web-services

Question

I'm creating aws eks cluster via terraform, but when i create cluster nodegroup with launch template i got 2 launch templates - one is with name and settings that i specify and second is with random name but with setting that i specify. Only difference in this 2 launch templat is IAM instance profile that got 2nd group (that creates automatically).
If i trying to specify IAM instance profile in my group it gives error that i cannot use it here
Is i'm doing something wrong or it's normal that it's creates 2 launch template ?
# eks node launch template
resource "aws_launch_template" "this" {
name = "${var.eks_cluster_name}-node-launch-template"
instance_type = var.instance_types[0]
image_id = var.node_ami
block_device_mappings {
device_name = "/dev/xvda"
ebs {
volume_size = 80
volume_type = "gp3"
throughput = "125"
encrypted = false
iops = 3000
}
}
lifecycle {
create_before_destroy = true
}
network_interfaces {
security_groups = [data.aws_eks_cluster.this.vpc_config[0].cluster_security_group_id]
}
user_data = base64encode(templatefile("${path.module}/userdata.tpl", merge(local.userdata_vars, local.cluster_data)))
tags = {
"eks:cluster-name" = var.eks_cluster_name
"eks:nodegroup-name" = var.node_group_name
}
tag_specifications {
resource_type = "instance"
tags = {
Name = "${var.eks_cluster_name}-node"
"eks:cluster-name" = var.eks_cluster_name
"eks:nodegroup-name" = var.node_group_name
}
}
tag_specifications {
resource_type = "volume"
tags = {
"eks:cluster-name" = var.eks_cluster_name
"eks:nodegroup-name" = var.node_group_name
}
}
}
# eks nodes
resource "aws_eks_node_group" "this" {
cluster_name = aws_eks_cluster.this.name
node_group_name = var.node_group_name
node_role_arn = aws_iam_role.eksNodesGroup.arn
subnet_ids = data.aws_subnet_ids.private.ids
scaling_config {
desired_size = 1
max_size = 10
min_size = 1
}
update_config {
max_unavailable = 1
}
launch_template {
version = aws_launch_template.this.latest_version
id = aws_launch_template.this.id
}
lifecycle {
create_before_destroy = true
ignore_changes = [
scaling_config[0].desired_size
]
}
# Ensure that IAM Role permissions are created before and deleted after EKS Node Group handling.
# Otherwise, EKS will not be able to properly delete EC2 Instances and Elastic Network Interfaces.
depends_on = [
aws_iam_role_policy_attachment.AmazonEKSWorkerNodePolicy,
aws_iam_role_policy_attachment.AmazonEKS_CNI_Policy,
aws_iam_role_policy_attachment.AmazonEC2ContainerRegistryReadOnly,
aws_launch_template.this
]
}
Expecting that terraform will create one launch template

Answer 1

Change the attribute name by name_prefix
Use:
name_prefix = "${var.eks_cluster_name}-node-launch-template"
Instead of:
name = "${var.eks_cluster_name}-node-launch-template"
The best choice to create a Unique name for a launch template using prefix (in your case ${var.eks_cluster_name}) is the name_prefix attribute.
Read more here