Easier overriding of workers_group_defaults (#107)

Author: dpiddockcmp

CHANGELOG.md

@@ -16,8 +16,8 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
-- A subtle but thoughtful change. (Boomshakalaka, @self 🏀)
 - **Breaking change** Removed `workstation_cidr` variable, http callout and unnecessary security rule. (by @dpiddockcmp)
+- Can now selectively override keys in `workers_group_defaults` variable rather than callers maintaining a duplicate of the whole map. (by @dpiddockcmp)
 
 ## [[v1.4.0](https://github.com/terraform-aws-modules/terraform-aws-eks/compare/v1.3.0...v1.4.0)] - 2018-08-02]
 

README.md

@@ -117,7 +117,7 @@ MIT Licensed. See [LICENSE](https://github.com/terraform-aws-modules/terraform-a
 | worker_groups | A list of maps defining worker group configurations. See workers_group_defaults for valid keys. | list | `<list>` | no |
 | worker_security_group_id | If provided, all workers will be attached to this security group. If not given, a security group will be created with necessary ingres/egress to work with the EKS cluster. | string | `` | no |
 | worker_sg_ingress_from_port | Minimum port number from which pods will accept communication. Must be changed to a lower value if some pods in your cluster will expose a port lower than 1025 (e.g. 22, 80, or 443). | string | `1025` | no |
-| workers_group_defaults | Default values for target groups as defined by the list of maps. | map | `<map>` | no |
+| workers_group_defaults | Override default values for target groups. See workers_group_defaults_defaults in locals.tf for valid keys. | map | `<map>` | no |
 | write_kubeconfig | Whether to write a kubeconfig file containing the cluster configuration. | string | `true` | no |
 
 ## Outputs

data.tf

@@ -78,9 +78,9 @@ data "template_file" "userdata" {
     cluster_name        = "${aws_eks_cluster.this.name}"
     endpoint            = "${aws_eks_cluster.this.endpoint}"
     cluster_auth_base64 = "${aws_eks_cluster.this.certificate_authority.0.data}"
-    max_pod_count       = "${lookup(local.max_pod_per_node, lookup(var.worker_groups[count.index], "instance_type", lookup(var.workers_group_defaults, "instance_type")))}"
-    pre_userdata        = "${lookup(var.worker_groups[count.index], "pre_userdata",lookup(var.workers_group_defaults, "pre_userdata"))}"
-    additional_userdata = "${lookup(var.worker_groups[count.index], "additional_userdata",lookup(var.workers_group_defaults, "additional_userdata"))}"
-    kubelet_node_labels = "${lookup(var.worker_groups[count.index], "kubelet_node_labels",lookup(var.workers_group_defaults, "kubelet_node_labels"))}"
+    max_pod_count       = "${lookup(local.max_pod_per_node, lookup(var.worker_groups[count.index], "instance_type", lookup(local.workers_group_defaults, "instance_type")))}"
+    pre_userdata        = "${lookup(var.worker_groups[count.index], "pre_userdata",lookup(local.workers_group_defaults, "pre_userdata"))}"
+    additional_userdata = "${lookup(var.worker_groups[count.index], "additional_userdata",lookup(local.workers_group_defaults, "additional_userdata"))}"
+    kubelet_node_labels = "${lookup(var.worker_groups[count.index], "kubelet_node_labels",lookup(local.workers_group_defaults, "kubelet_node_labels"))}"
   }
 }

local.tf

@@ -8,6 +8,30 @@ locals {
   worker_security_group_id = "${coalesce(join("", aws_security_group.workers.*.id), var.worker_security_group_id)}"
   kubeconfig_name          = "${var.kubeconfig_name == "" ? "eks_${var.cluster_name}" : var.kubeconfig_name}"
 
+  workers_group_defaults_defaults = {
+    name                 = "count.index" # Name of the worker group. Literal count.index will never be used but if name is not set, the count.index interpolation will be used.
+    ami_id               = ""            # AMI ID for the eks workers. If none is provided, Terraform will search for the latest version of their EKS optimized worker AMI.
+    asg_desired_capacity = "1"           # Desired worker capacity in the autoscaling group.
+    asg_max_size         = "3"           # Maximum worker capacity in the autoscaling group.
+    asg_min_size         = "1"           # Minimum worker capacity in the autoscaling group.
+    instance_type        = "m4.large"    # Size of the workers instances.
+    spot_price           = ""            # Cost of spot instance.
+    root_volume_size     = "100"         # root volume size of workers instances.
+    root_volume_type     = "gp2"         # root volume type of workers instances, can be 'standard', 'gp2', or 'io1'
+    root_iops            = "0"           # The amount of provisioned IOPS. This must be set with a volume_type of "io1".
+    key_name             = ""            # The key name that should be used for the instances in the autoscaling group
+    pre_userdata         = ""            # userdata to pre-append to the default userdata.
+    additional_userdata  = ""            # userdata to append to the default userdata.
+    ebs_optimized        = true          # sets whether to use ebs optimization on supported types.
+    enable_monitoring    = true          # Enables/disables detailed monitoring.
+    public_ip            = false         # Associate a public ip address with a worker
+    kubelet_node_labels  = ""            # This string is passed directly to kubelet via --node-labels= if set. It should be comma delimited with no spaces. If left empty no --node-labels switch is added.
+    subnets              = ""            # A comma delimited string of subnets to place the worker nodes in. i.e. subnet-123,subnet-456,subnet-789
+    autoscaling_enabled  = false         # Sets whether policy and matching tags will be added to allow autoscaling.
+  }
+
+  workers_group_defaults = "${merge(local.workers_group_defaults_defaults, var.workers_group_defaults)}"
+
   # Mapping from the node type that we selected and the max number of pods that it can run
   # Taken from https://amazon-eks.s3-us-west-2.amazonaws.com/1.10.3/2018-06-05/amazon-eks-nodegroup.yaml
   max_pod_per_node = {

variables.tf

@@ -76,30 +76,9 @@ variable "worker_group_count" {
 }
 
 variable "workers_group_defaults" {
-  description = "Default values for target groups as defined by the list of maps."
+  description = "Override default values for target groups. See workers_group_defaults_defaults in locals.tf for valid keys."
   type        = "map"
-
-  default = {
-    name                 = "count.index" # Name of the worker group. Literal count.index will never be used but if name is not set, the count.index interpolation will be used.
-    ami_id               = ""            # AMI ID for the eks workers. If none is provided, Terraform will search for the latest version of their EKS optimized worker AMI.
-    asg_desired_capacity = "1"           # Desired worker capacity in the autoscaling group.
-    asg_max_size         = "3"           # Maximum worker capacity in the autoscaling group.
-    asg_min_size         = "1"           # Minimum worker capacity in the autoscaling group.
-    instance_type        = "m4.large"    # Size of the workers instances.
-    spot_price           = ""            # Cost of spot instance.
-    root_volume_size     = "100"         # root volume size of workers instances.
-    root_volume_type     = "gp2"         # root volume type of workers instances, can be 'standard', 'gp2', or 'io1'
-    root_iops            = "0"           # The amount of provisioned IOPS. This must be set with a volume_type of "io1".
-    key_name             = ""            # The key name that should be used for the instances in the autoscaling group
-    pre_userdata         = ""            # userdata to pre-append to the default userdata.
-    additional_userdata  = ""            # userdata to append to the default userdata.
-    ebs_optimized        = true          # sets whether to use ebs optimization on supported types.
-    enable_monitoring    = true          # Enables/disables detailed monitoring.
-    public_ip            = false         # Associate a public ip address with a worker
-    kubelet_node_labels  = ""            # This string is passed directly to kubelet via --node-labels= if set. It should be comma delimited with no spaces. If left empty no --node-labels switch is added.
-    subnets              = ""            # A comma delimited string of subnets to place the worker nodes in. i.e. subnet-123,subnet-456,subnet-789
-    autoscaling_enabled  = false         # Sets whether policy and matching tags will be added to allow autoscaling.
-  }
+  default     = {}
 }
 
 variable "worker_security_group_id" {

workers.tf

@@ -1,8 +1,8 @@
 resource "aws_autoscaling_group" "workers" {
   name_prefix          = "${aws_eks_cluster.this.name}-${lookup(var.worker_groups[count.index], "name", count.index)}"
-  desired_capacity     = "${lookup(var.worker_groups[count.index], "asg_desired_capacity", lookup(var.workers_group_defaults, "asg_desired_capacity"))}"
-  max_size             = "${lookup(var.worker_groups[count.index], "asg_max_size",lookup(var.workers_group_defaults, "asg_max_size"))}"
-  min_size             = "${lookup(var.worker_groups[count.index], "asg_min_size",lookup(var.workers_group_defaults, "asg_min_size"))}"
+  desired_capacity     = "${lookup(var.worker_groups[count.index], "asg_desired_capacity", lookup(local.workers_group_defaults, "asg_desired_capacity"))}"
+  max_size             = "${lookup(var.worker_groups[count.index], "asg_max_size",lookup(local.workers_group_defaults, "asg_max_size"))}"
+  min_size             = "${lookup(var.worker_groups[count.index], "asg_min_size",lookup(local.workers_group_defaults, "asg_min_size"))}"
   launch_configuration = "${element(aws_launch_configuration.workers.*.id, count.index)}"
   vpc_zone_identifier  = ["${split(",", coalesce(lookup(var.worker_groups[count.index], "subnets", ""), join(",", var.subnets)))}"]
   count                = "${var.worker_group_count}"
@@ -23,26 +23,26 @@ resource "aws_autoscaling_group" "workers" {
 
 resource "aws_launch_configuration" "workers" {
   name_prefix                 = "${aws_eks_cluster.this.name}-${lookup(var.worker_groups[count.index], "name", count.index)}"
-  associate_public_ip_address = "${lookup(var.worker_groups[count.index], "public_ip", lookup(var.workers_group_defaults, "public_ip"))}"
+  associate_public_ip_address = "${lookup(var.worker_groups[count.index], "public_ip", lookup(local.workers_group_defaults, "public_ip"))}"
   security_groups             = ["${local.worker_security_group_id}"]
   iam_instance_profile        = "${aws_iam_instance_profile.workers.id}"
   image_id                    = "${lookup(var.worker_groups[count.index], "ami_id", data.aws_ami.eks_worker.id)}"
-  instance_type               = "${lookup(var.worker_groups[count.index], "instance_type", lookup(var.workers_group_defaults, "instance_type"))}"
-  key_name                    = "${lookup(var.worker_groups[count.index], "key_name", lookup(var.workers_group_defaults, "key_name"))}"
+  instance_type               = "${lookup(var.worker_groups[count.index], "instance_type", lookup(local.workers_group_defaults, "instance_type"))}"
+  key_name                    = "${lookup(var.worker_groups[count.index], "key_name", lookup(local.workers_group_defaults, "key_name"))}"
   user_data_base64            = "${base64encode(element(data.template_file.userdata.*.rendered, count.index))}"
-  ebs_optimized               = "${lookup(var.worker_groups[count.index], "ebs_optimized", lookup(local.ebs_optimized, lookup(var.worker_groups[count.index], "instance_type", lookup(var.workers_group_defaults, "instance_type")), false))}"
-  enable_monitoring           = "${lookup(var.worker_groups[count.index], "enable_monitoring", lookup(var.workers_group_defaults, "enable_monitoring"))}"
-  spot_price                  = "${lookup(var.worker_groups[count.index], "spot_price", lookup(var.workers_group_defaults, "spot_price"))}"
+  ebs_optimized               = "${lookup(var.worker_groups[count.index], "ebs_optimized", lookup(local.ebs_optimized, lookup(var.worker_groups[count.index], "instance_type", lookup(local.workers_group_defaults, "instance_type")), false))}"
+  enable_monitoring           = "${lookup(var.worker_groups[count.index], "enable_monitoring", lookup(local.workers_group_defaults, "enable_monitoring"))}"
+  spot_price                  = "${lookup(var.worker_groups[count.index], "spot_price", lookup(local.workers_group_defaults, "spot_price"))}"
   count                       = "${var.worker_group_count}"
 
   lifecycle {
     create_before_destroy = true
   }
 
   root_block_device {
-    volume_size           = "${lookup(var.worker_groups[count.index], "root_volume_size", lookup(var.workers_group_defaults, "root_volume_size"))}"
-    volume_type           = "${lookup(var.worker_groups[count.index], "root_volume_type", lookup(var.workers_group_defaults, "root_volume_type"))}"
-    iops                  = "${lookup(var.worker_groups[count.index], "root_iops", lookup(var.workers_group_defaults, "root_iops"))}"
+    volume_size           = "${lookup(var.worker_groups[count.index], "root_volume_size", lookup(local.workers_group_defaults, "root_volume_size"))}"
+    volume_type           = "${lookup(var.worker_groups[count.index], "root_volume_type", lookup(local.workers_group_defaults, "root_volume_type"))}"
+    iops                  = "${lookup(var.worker_groups[count.index], "root_iops", lookup(local.workers_group_defaults, "root_iops"))}"
     delete_on_termination = true
   }
 }