Moved node-config to be local, added AMI vars.

example.tfvars

@@ -21,19 +21,6 @@ aws-ec2-instance-type = "t2.micro"
 # 4 GiB, 2 vcpus
 # aws-ec2-instnce-type = "t2.medium"
 
-################################################################################
-
-nodes-config = {
-  "master" = {
-    base-image = "ami-0dd0ccab7e2801812"
-    num = 1
-  },
-  "worker" = {
-    base-image = "ami-0dd0ccab7e2801812"
-    num = 2
-  }
-}
-
 ################################################################################
 # AWS images (AMIs)
 ################################################################################

get-vm-ips.sh

@@ -48,6 +48,7 @@ ANSIBLE_INV="$(
         sed -z 's/\n/,/g;s/,$/\n/g')"
 
 # Create an inventory file for ansible.
+echo "# Wrote an Ansible inventory file at ./inventory"
 echo "[k8s_nodes]" > inventory
 echo $VM_IP_EXPORTS | \
     sed 's/"//g' | \

main.tf

@@ -8,12 +8,25 @@ terraform {
   }
 }
 
+locals {
+  nodes-config = {
+    "master" = {
+      base-image = var.amzn2-ami
+      num = 1
+    },
+    "worker" = {
+      base-image = var.amzn2-ami
+      num = 2
+    }
+  }
+}
+
 ################################################################################
 # cloud-init
 ################################################################################
 
 module "cloud-init-config" {
-  for_each            = var.nodes-config
+  for_each            = local.nodes-config
   source              = "./modules/cloud-init-config"
   cloud-init-template = "${path.module}/cloud_init.cfg"
   hostname-prefix     = "${var.vm-name-prefix}-${each.key}"
@@ -32,7 +45,8 @@ provider "aws" {
   region = "us-east-2"
 }
 
-# This module will grab the latest ami for a variety of distros.
+# This module will grab the latest ami for a variety of distros. Uncomment to
+# get a list of the latest AMIs for our supported distros.
 # module "aws-amis" {
 #   source = "./modules/aws-amis"
 # }
@@ -59,7 +73,7 @@ resource "aws_key_pair" "key" {
 }
 
 module "nodes" {
-  for_each           = var.nodes-config
+  for_each           = local.nodes-config
   source             = "./modules/aws-nodes"
   ami                = each.value.base-image
   ec2-instance-type  = var.aws-ec2-instance-type
@@ -85,7 +99,7 @@ module "nodes" {
 # }
 # 
 # module "nodes" {
-#   for_each               = var.nodes-config
+#   for_each               = local.nodes-config
 #   source                 = "./modules/libvirt-nodes"
 #   pool-name              = libvirt_pool.images.name
 #   name-prefix            = "${var.vm-name-prefix}-${each.key}"

variables.tf

@@ -43,11 +43,6 @@ variable "node-vcpus" {
   type        = number
 }
 
-variable "nodes-config" {
-  description = "A config that declares how many nodes of each type you want created."
-  type = map(object({base-image=string,num=number}))
-}
-
 variable "root-admin-passwd" {
   description = "This will be the password for the root and admin user. The format of this can by any format accepted by cloud-init's chpasswd module."
 }
@@ -76,3 +71,39 @@ variable "vm-name-prefix" {
   default = "k8s-tf"
   description = "This prefix will appear before all VM names and hostnames, ie. k8s-tf-master-0."
 }
+
+################################################################################
+# AWS AMI vars
+# These variables are really mor like constants. Using variables improves
+# readability. The defaults are manually updated. Use the aws-amis module to get
+# the latest for each distro.
+################################################################################
+
+variable "amzn2-ami" {
+  default     = "ami-0dd0ccab7e2801812"
+  description = "The AMI to use for Amazon Linux 2."
+}
+variable "ubuntu-ami" {
+  default = "ami-06c7d6c0987eaa46c"
+  description = "The AMI to use for Ubuntu."
+}
+variable "centos7-ami" {
+  default = "ami-00f8e2c955f7ffa9b"
+  description = "The AMI to use for CentOS 7."
+}
+variable "centos8-ami" {
+  default = "ami-057cacbfbbb471bb3"
+  description = "The AMI to use for CentOS 8."
+}
+variable "arch-ami" {
+  default = "ami-02653f06de985e3ba"
+  description = "The AMI to use for Arch Linux."
+}
+variable "rhel7-ami" {
+  default = "ami-0a509b3c2a4d05b3f"
+  description = "The AMI to use for RHEL 7."
+}
+variable "rhel8-ami" {
+  default = "ami-0d871ca8a77af2948"
+  description = "The AMI to use for RHEL 8."
+}