feat: Drop random pets from Managed Node Groups (#1372)

BREAKING CHANGES: We now decided to remove `random_pet` resources in Managed Node Groups (MNG). Those were used to recreate MNG if something change and also simulate the newly added argument `node_group_name_prefix`. But they were causing a lot of troubles. 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. Please see [upgrade docs](https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/docs/upgrades.md#upgrade-module-to-v1700-for-managed-node-groups) for more details.

README.md

@@ -143,17 +143,16 @@ Apache 2 Licensed. See [LICENSE](https://github.com/terraform-aws-modules/terraf
 | Name | Version |
 |------|---------|
 | <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 0.13.1 |
-| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.37.0 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.40.0 |
 | <a name="requirement_http"></a> [http](#requirement\_http) | >= 2.4.1 |
 | <a name="requirement_kubernetes"></a> [kubernetes](#requirement\_kubernetes) | >= 1.11.1 |
 | <a name="requirement_local"></a> [local](#requirement\_local) | >= 1.4 |
-| <a name="requirement_random"></a> [random](#requirement\_random) | >= 2.1 |
 
 ## Providers
 
 | Name | Version |
 |------|---------|
-| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.37.0 |
+| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.40.0 |
 | <a name="provider_http"></a> [http](#provider\_http) | >= 2.4.1 |
 | <a name="provider_kubernetes"></a> [kubernetes](#provider\_kubernetes) | >= 1.11.1 |
 | <a name="provider_local"></a> [local](#provider\_local) | >= 1.4 |

aws_auth.tf

@@ -1,5 +1,3 @@
-data "aws_caller_identity" "current" {}
-
 locals {
   auth_launch_template_worker_roles = [
     for index in range(0, var.create_eks ? local.worker_group_launch_template_count : 0) : {

data.tf

@@ -1,3 +1,7 @@
+data "aws_partition" "current" {}
+
+data "aws_caller_identity" "current" {}
+
 data "aws_iam_policy_document" "workers_assume_role_policy" {
   statement {
     sid = "EKSWorkerAssumeRole"
@@ -82,8 +86,6 @@ data "aws_iam_instance_profile" "custom_worker_group_launch_template_iam_instanc
   )
 }
 
-data "aws_partition" "current" {}
-
 data "http" "wait_for_cluster" {
   count          = var.create_eks && var.manage_aws_auth ? 1 : 0
   url            = format("%s/healthz", aws_eks_cluster.this[0].endpoint)

docs/upgrades.md

@@ -0,0 +1,60 @@
+# 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
+```shell
+~ 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
+```hcl
+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 shoud see that only `random_pets` will be destroyed
+
+```shell
+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 recommand 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 collision during node groups re-creation if needed, because the lifce cycle is `create_before_destroy = true`.

examples/managed_node_groups/main.tf

@@ -78,7 +78,7 @@ module "eks" {
       max_capacity     = 10
       min_capacity     = 1
 
-      instance_types = ["m5.large"]
+      instance_types = ["t3.large"]
       capacity_type  = "SPOT"
       k8s_labels = {
         Environment = "test"

modules/fargate/README.md

@@ -21,13 +21,13 @@ Helper submodule to create and manage resources related to `aws_eks_fargate_prof
 | Name | Version |
 |------|---------|
 | <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 0.13.1 |
-| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.22.0 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.40.0 |
 
 ## Providers
 
 | Name | Version |
 |------|---------|
-| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.22.0 |
+| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.40.0 |
 
 ## Modules
 

modules/fargate/versions.tf

@@ -2,6 +2,6 @@ terraform {
   required_version = ">= 0.13.1"
 
   required_providers {
-    aws = ">= 3.22.0"
+    aws = ">= 3.40.0"
   }
 }

modules/node_groups/README.md

@@ -21,28 +21,29 @@ The role ARN specified in `var.default_iam_role_arn` will be used by default. In
 | ami\_release\_version | AMI version of workers | string | Provider default behavior |
 | ami\_type | AMI Type. See Terraform or AWS docs | string | Provider default behavior |
 | capacity\_type | Type of instance capacity to provision. Options are `ON_DEMAND` and `SPOT` | string | Provider default behavior |
-| force\_update\_version | Force version update if existing pods are unable to be drained due to a pod disruption budget issue. | bool | Provider default behavior |
+| create_launch_template | Create and use a default launch template | bool |  `false` |
 | desired\_capacity | Desired number of workers | number | `var.workers_group_defaults[asg_desired_capacity]` |
 | disk\_size | Workers' disk size | number | Provider default behavior |
 | disk\_type | Workers' disk type. Require `create_launch_template` to be `true`| number | `gp3` |
+| enable_monitoring | Enables/disables detailed monitoring. Require `create_launch_template` to be `true`| bool | `true` |
+| eni_delete | Delete the Elastic Network Interface (ENI) on termination (if set to false you will have to manually delete before destroying) | bool | `true` |
+| force\_update\_version | Force version update if existing pods are unable to be drained due to a pod disruption budget issue. | bool | Provider default behavior |
 | iam\_role\_arn | IAM role ARN for workers | string | `var.default_iam_role_arn` |
 | instance\_types | Node group's instance type(s). Multiple types can be specified when `capacity_type="SPOT"`. | list | `[var.workers_group_defaults[instance_type]]` |
 | k8s\_labels | Kubernetes labels | map(string) | No labels applied |
 | key\_name | Key name for workers. Set to empty string to disable remote access | string | `var.workers_group_defaults[key_name]` |
+| kubelet_extra_args | This string is passed directly to kubelet if set. Useful for adding labels or taints. Require `create_launch_template` to be `true`| string | "" |
 | launch_template_id | The id of a aws_launch_template to use | string | No LT used |
 | launch\_template_version | The version of the LT to use | string | none |
 | max\_capacity | Max number of workers | number | `var.workers_group_defaults[asg_max_size]` |
 | min\_capacity | Min number of workers | number | `var.workers_group_defaults[asg_min_size]` |
-| name | Name of the node group | string | Auto generated |
+| name | Name of the node group. If you don't really need this, we recommend you to use `name_prefix` instead. | string | Will use the autogenerate name prefix |
+| name_prefix | Name prefix of the node group | string | Auto generated |
+| pre_userdata | userdata to pre-append to the default userdata. Require `create_launch_template` to be `true`| string | "" |
+| public_ip | Associate a public ip address with a worker. Require `create_launch_template` to be `true`| string | `false`
 | source\_security\_group\_ids | Source security groups for remote access to workers | list(string) | If key\_name is specified: THE REMOTE ACCESS WILL BE OPENED TO THE WORLD |
 | subnets | Subnets to contain workers | list(string) | `var.workers_group_defaults[subnets]` |
 | version | Kubernetes version | string | Provider default behavior |
-| create_launch_template | Create and use a default launch template | bool |  `false` |
-| kubelet_extra_args | This string is passed directly to kubelet if set. Useful for adding labels or taints. Require `create_launch_template` to be `true`| string | "" |
-| enable_monitoring | Enables/disables detailed monitoring. Require `create_launch_template` to be `true`| bool | `true` |
-| eni_delete | Delete the Elastic Network Interface (ENI) on termination (if set to false you will have to manually delete before destroying) | bool | `true` |
-| public_ip | Associate a public ip address with a worker. Require `create_launch_template` to be `true`| string | `false`
-| pre_userdata | userdata to pre-append to the default userdata. Require `create_launch_template` to be `true`| string | "" |
 
 <!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->
 ## Requirements
@@ -50,16 +51,14 @@ The role ARN specified in `var.default_iam_role_arn` will be used by default. In
 | Name | Version |
 |------|---------|
 | <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 0.13.1 |
-| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.22.0 |
-| <a name="requirement_random"></a> [random](#requirement\_random) | >= 2.1 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.40.0 |
 
 ## Providers
 
 | Name | Version |
 |------|---------|
-| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.22.0 |
+| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.40.0 |
 | <a name="provider_cloudinit"></a> [cloudinit](#provider\_cloudinit) | n/a |
-| <a name="provider_random"></a> [random](#provider\_random) | >= 2.1 |
 
 ## Modules
 
@@ -71,7 +70,6 @@ No modules.
 |------|------|
 | [aws_eks_node_group.workers](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/eks_node_group) | resource |
 | [aws_launch_template.workers](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/launch_template) | resource |
-| [random_pet.node_groups](https://registry.terraform.io/providers/hashicorp/random/latest/docs/resources/pet) | resource |
 | [cloudinit_config.workers_userdata](https://registry.terraform.io/providers/hashicorp/cloudinit/latest/docs/data-sources/config) | data source |
 
 ## Inputs

modules/node_groups/launch_template.tf

@@ -1,5 +1,6 @@
 data "cloudinit_config" "workers_userdata" {
-  for_each      = { for k, v in local.node_groups_expanded : k => v if v["create_launch_template"] }
+  for_each = { for k, v in local.node_groups_expanded : k => v if v["create_launch_template"] }
+
   gzip          = false
   base64_encode = true
   boundary      = "//"
@@ -12,7 +13,6 @@ data "cloudinit_config" "workers_userdata" {
         kubelet_extra_args = each.value["kubelet_extra_args"]
       }
     )
-
   }
 }
 
@@ -23,9 +23,10 @@ data "cloudinit_config" "workers_userdata" {
 # Trivia: AWS transparently creates a copy of your LaunchTemplate and actually uses that copy then for the node group. If you DONT use a custom AMI,
 # then the default user-data for bootstrapping a cluster is merged in the copy.
 resource "aws_launch_template" "workers" {
-  for_each               = { for k, v in local.node_groups_expanded : k => v if v["create_launch_template"] }
-  name_prefix            = lookup(each.value, "name", join("-", [var.cluster_name, each.key, random_pet.node_groups[each.key].id]))
-  description            = lookup(each.value, "name", join("-", [var.cluster_name, each.key, random_pet.node_groups[each.key].id]))
+  for_each = { for k, v in local.node_groups_expanded : k => v if v["create_launch_template"] }
+
+  name_prefix            = local.node_groups_names[each.key]
+  description            = format("EKS Managed Node Group custom LT for %s", local.node_groups_names[each.key])
   update_default_version = true
 
   block_device_mappings {
@@ -79,7 +80,7 @@ resource "aws_launch_template" "workers" {
       lookup(var.node_groups_defaults, "additional_tags", {}),
       lookup(var.node_groups[each.key], "additional_tags", {}),
       {
-        Name = lookup(each.value, "name", join("-", [var.cluster_name, each.key, random_pet.node_groups[each.key].id]))
+        Name = local.node_groups_names[each.key]
       }
     )
   }
@@ -93,12 +94,12 @@ resource "aws_launch_template" "workers" {
       lookup(var.node_groups_defaults, "additional_tags", {}),
       lookup(var.node_groups[each.key], "additional_tags", {}),
       {
-        Name = lookup(each.value, "name", join("-", [var.cluster_name, each.key, random_pet.node_groups[each.key].id]))
+        Name = local.node_groups_names[each.key]
       }
     )
   }
 
-  # Supplying custom tags to EKS instances ENI's  
+  # Supplying custom tags to EKS instances ENI's
   tag_specifications {
     resource_type = "network-interface"
 
@@ -107,7 +108,7 @@ resource "aws_launch_template" "workers" {
       lookup(var.node_groups_defaults, "additional_tags", {}),
       lookup(var.node_groups[each.key], "additional_tags", {}),
       {
-        Name = lookup(each.value, "name", join("-", [var.cluster_name, each.key, random_pet.node_groups[each.key].id]))
+        Name = local.node_groups_names[each.key]
       }
     )
   }

modules/node_groups/locals.tf

@@ -25,4 +25,14 @@ locals {
     var.node_groups_defaults,
     v,
   ) if var.create_eks }
+
+  node_groups_names = { for k, v in local.node_groups_expanded : k => lookup(
+    v,
+    "name",
+    lookup(
+      v,
+      "name_prefix",
+      join("-", [var.cluster_name, k])
+    )
+  ) }
 }

modules/node_groups/node_groups.tf

@@ -1,7 +1,8 @@
 resource "aws_eks_node_group" "workers" {
   for_each = local.node_groups_expanded
 
-  node_group_name = lookup(each.value, "name", join("-", [var.cluster_name, each.key, random_pet.node_groups[each.key].id]))
+  node_group_name_prefix = lookup(each.value, "name", null) == null ? local.node_groups_names[each.key] : null
+  node_group_name        = lookup(each.value, "name", null)
 
   cluster_name  = var.cluster_name
   node_role_arn = each.value["iam_role_arn"]

modules/node_groups/random.tf

@@ -1,27 +0,0 @@
-resource "random_pet" "node_groups" {
-  for_each = local.node_groups_expanded
-
-  separator = "-"
-  length    = 2
-
-  keepers = {
-    ami_type      = lookup(each.value, "ami_type", null)
-    disk_size     = lookup(each.value, "disk_size", null)
-    capacity_type = lookup(each.value, "capacity_type", null)
-    iam_role_arn  = each.value["iam_role_arn"]
-    instance_types = join("|", compact(
-      lookup(each.value, "instance_types", [])
-    ))
-
-    key_name = each.value["key_name"]
-
-    source_security_group_ids = join("|", compact(
-      lookup(each.value, "source_security_group_ids", [])
-    ))
-    subnet_ids      = join("|", each.value["subnets"])
-    node_group_name = join("-", [var.cluster_name, each.key])
-    launch_template = lookup(each.value, "launch_template_id", null)
-  }
-
-  depends_on = [var.ng_depends_on]
-}

modules/node_groups/versions.tf

@@ -2,7 +2,6 @@ terraform {
   required_version = ">= 0.13.1"
 
   required_providers {
-    aws    = ">= 3.22.0"
-    random = ">= 2.1"
+    aws = ">= 3.40.0"
   }
 }

versions.tf

@@ -2,9 +2,8 @@ terraform {
   required_version = ">= 0.13.1"
 
   required_providers {
-    aws        = ">= 3.37.0"
+    aws        = ">= 3.40.0"
     local      = ">= 1.4"
-    random     = ">= 2.1"
     kubernetes = ">= 1.11.1"
     http = {
       source  = "terraform-aws-modules/http"