fix: upgrade to terraform v0.12, lock provider versions

Fixes dwmkerr#88.

README.md

@@ -51,7 +51,7 @@ created, which is used to install the OpenShift Origin platform on the hosts.
 
 You need:
 
-1. [Terraform](https://www.terraform.io/intro/getting-started/install.html) - `brew update && brew install terraform`
+1. [Terraform (0.12 or greater)](https://www.terraform.io/intro/getting-started/install.html) - `brew update && brew install terraform`
 2. An AWS account, configured with the cli locally -
 ```
 if [[ "$unamestr" == 'Linux' ]]; then

main.tf

@@ -1,6 +1,15 @@
-//  Setup the core provider information.
+# Setup our providers so that we have deterministic dependecy resolution. 
 provider "aws" {
   region  = "${var.region}"
+  version = "~> 2.19"
+}
+
+provider "local" {
+  version = "~> 1.3"
+}
+
+provider "template" {
+  version = "~> 2.1"
 }
 
 //  Create the OpenShift cluster using our module.

modules/openshift/06-nodes.tf

@@ -7,7 +7,7 @@ resource "aws_key_pair" "keypair" {
 //  Create the master userdata script.
 data "template_file" "setup-master" {
   template = "${file("${path.module}/files/setup-master.sh")}"
-  vars {
+  vars = {
     availability_zone = "${data.aws_availability_zones.azs.names[0]}"
   }
 }
@@ -61,7 +61,7 @@ resource "aws_instance" "master" {
 //  Create the node userdata script.
 data "template_file" "setup-node" {
   template = "${file("${path.module}/files/setup-node.sh")}"
-  vars {
+  vars = {
     availability_zone = "${data.aws_availability_zones.azs.names[0]}"
   }
 }

modules/openshift/07-dns.tf

@@ -8,7 +8,7 @@ resource "aws_route53_zone" "internal" {
   vpc {
     vpc_id = "${aws_vpc.openshift.id}"
   }
-  tags {
+  tags = {
     Name    = "OpenShift Internal DNS"
     Project = "openshift"
   }

modules/openshift/09-inventory.tf

@@ -2,7 +2,7 @@
 //  inventory from the inventory template.
 data "template_file" "inventory" {
   template = "${file("${path.cwd}/inventory.template.cfg")}"
-  vars {
+  vars = {
     access_key = "${aws_iam_access_key.openshift-aws-user.id}"
     secret_key = "${aws_iam_access_key.openshift-aws-user.secret}"
     public_hostname = "${aws_eip.master_eip.public_ip}.xip.io"