terraform failes to create eks_node group - terraform

Question

resource "aws_eks_node_group" "n-cluster-group" {
cluster_name = aws_eks_cluster.n-cluster.name
node_group_name = "n-cluster-group"
node_role_arn = aws_iam_role.eks-nodegroup.arn
subnet_ids = [aws_subnet.public.id, aws_subnet.public2.id]
scaling_config {
desired_size = 3
max_size = 6
min_size = 1
}
launch_template {
id = aws_launch_template.n-cluster.id
version = aws_launch_template.n-cluster.latest_version
}
depends_on = [
aws_iam_role_policy_attachment.AmazonEKSWorkerNodePolicy,
aws_iam_role_policy_attachment.AmazonEC2ContainerRegistryReadOnly,
aws_iam_role_policy_attachment.AmazonEKS_CNI_Policy,
]
resource "aws_launch_template" "n-cluster" {
image_id = "ami-0d45236a5972906dd"
instance_type = "t3.medium"
name_prefix = "cluster-node-"
block_device_mappings {
device_name = "/dev/sda1"
ebs {
volume_size = 20
}
}
Although instances appear to successfully createthe node group status is CREATE_FAILED terraform reports this as well.
I am wondering what CREATE_FAILED means
what am I dooing wrong? when using a launch group and an eks optomized AMI should I still specify user_data and if so what is the correct way to do this using terraform.

Answer 1

I managed to solve the issue with the following configurations:
resource "aws_launch_template" "eks_launch_template" {
name = "eks_launch_template"
block_device_mappings {
device_name = "/dev/xvda"
ebs {
volume_size = 20
volume_type = "gp2"
}
}
image_id = <custom_ami_id>
instance_type = "t3.medium"
user_data = filebase64("${path.module}/eks-user-data.sh")
tag_specifications {
resource_type = "instance"
tags = {
Name = "EKS-MANAGED-NODE"
}
}
}
resource "aws_eks_node_group" "eks-cluster-ng" {
cluster_name = aws_eks_cluster.eks-cluster.name
node_group_name = "eks-cluster-ng-"
node_role_arn = aws_iam_role.eks-cluster-ng.arn
subnet_ids = [var.network_subnets.pvt[0].id, var.network_subnets.pvt[1].id, var.network_subnets.pvt[2].id]
scaling_config {
desired_size = var.asg_desired_size
max_size = var.asg_max_size
min_size = var.asg_min_size
}
launch_template {
name = aws_launch_template.eks_launch_template.name
version = aws_launch_template.eks_launch_template.latest_version
}
depends_on = [
aws_iam_role_policy_attachment.AmazonEKSWorkerNodePolicy,
aws_iam_role_policy_attachment.AmazonEC2ContainerRegistryReadOnly,
aws_iam_role_policy_attachment.AmazonEKS_CNI_Policy,
]
}
The key lies with user_data = filebase64("${path.module}/eks-user-data.sh")
The eks-user-data.sh file should be something like this:
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="
--==MYBOUNDARY==
Content-Type: text/x-shellscript; charset="us-ascii"
#!/bin/bash
/etc/eks/bootstrap.sh <cluster-name>
--==MYBOUNDARY==--\
I have tested the above and it works as intended. Thanks all for leading me to this solution

Answer 2

Adding this to your launch template definition resolves it:
user_data = base64encode(<<-EOF
#!/bin/bash -xe
/etc/eks/bootstrap.sh CLUSTER_NAME_HERE
EOF
)
I guess even a EKS optimised AMI counts as a custom AMI if used via launch template.