Rolled back main.tf to have master and worker.

main.tf

@@ -10,33 +10,13 @@ terraform {
 
 locals {
   nodes-config = {
-    "amzn2" = {
+    "master" = {
       base-image = var.amzn2-ami
       num = 1
     },
-    "ubuntu" = {
+    "worker" = {
-      base-image = var.ubuntu-ami
+      base-image = var.amzn2-ami
-      num = 1
+      num = 2
-    },
-    "arch" = {
-      base-image = var.arch-ami
-      num = 1
-    },
-    "centos7" = {
-      base-image = var.centos7-ami
-      num = 1
-    },
-    "centos8" = {
-      base-image = var.centos8-ami
-      num = 1
-    },
-    "rhel7" = {
-      base-image = var.rhel7-ami
-      num = 1
-    },
-    "rhel8" = {
-      base-image = var.rhel8-ami
-      num = 1
     }
   }
 }