UPGRADE-17.0.md

How to handle the terraform-aws-eks module upgrade

Upgrade module to v17.0.0 for Managed Node Groups

In this release, we now decided to remove random_pet resources in Managed Node Groups (MNG). Those were used to recreate MNG if something changed. But they were causing a lot of issues. To upgrade the module without recreating your MNG, you will need to explicitly reuse their previous name and set them in your MNG name argument.

1. Run terraform apply with the module version v16.2.0
2. Get your worker group names

~ terraform state show 'module.eks.module.node_groups.aws_eks_node_group.workers["example"]' | grep node_group_name
node_group_name = "test-eks-mwIwsvui-example-sincere-squid"

3. Upgrade your module and configure your node groups to use existing names

module "eks" {
  source  = "terraform-aws-modules/eks/aws"
  version = "17.0.0"

  cluster_name    = "test-eks-mwIwsvui"
  cluster_version = "1.20"
  # ...

  node_groups = {
    example = {
      name = "test-eks-mwIwsvui-example-sincere-squid"

      # ...
    }
  }
  # ...
}

4. Run terraform plan, you should see that only random_pets will be destroyed

Terraform will perform the following actions:

  # module.eks.module.node_groups.random_pet.node_groups["example"] will be destroyed
  - resource "random_pet" "node_groups" {
      - id        = "sincere-squid" -> null
      - keepers   = {
          - "ami_type"                  = "AL2_x86_64"
          - "capacity_type"             = "SPOT"
          - "disk_size"                 = "50"
          - "iam_role_arn"              = "arn:aws:iam::123456789123:role/test-eks-mwIwsvui20210527220853611600000009"
          - "instance_types"            = "t3.large"
          - "key_name"                  = ""
          - "node_group_name"           = "test-eks-mwIwsvui-example"
          - "source_security_group_ids" = ""
          - "subnet_ids"                = "subnet-xxxxxxxxxxxx|subnet-xxxxxxxxxxxx|subnet-xxxxxxxxxxxx"
        } -> null
      - length    = 2 -> null
      - separator = "-" -> null
    }

Plan: 0 to add, 0 to change, 1 to destroy.

5. If everything sounds good to you, run terraform apply

After the first apply, we recommend you to create a new node group and let the module use the node_group_name_prefix (by removing the name argument) to generate names and avoid collision during node groups re-creation if needed, because the lifecycle is create_before_destroy = true.