Rename CLC files and favor Terraform list index syntax

* Rename Container Linux Config (CLC) files to *.yaml to align
with Fedora CoreOS Config (FCC) files and for syntax highlighting
* Replace common uses of Terraform `element` (which wraps around)
with `list[index]` syntax to surface index errors

azure/container-linux/kubernetes/controllers.tf

@@ -11,16 +11,13 @@ resource "azurerm_dns_a_record" "etcds" {
   ttl  = 300
 
   # private IPv4 address for etcd
-  records = [element(
-    azurerm_network_interface.controllers.*.private_ip_address,
-    count.index,
-  )]
+  records = [azurerm_network_interface.controllers.*.private_ip_address[count.index]]
 }
 
 locals {
   # Channel for a Container Linux derivative
   # coreos-stable -> Container Linux Stable
-  channel = element(split("-", var.os_image), 1)
+  channel = split("-", var.os_image)[1]
 }
 
 # Controller availability set to spread controllers
@@ -63,12 +60,12 @@ resource "azurerm_virtual_machine" "controllers" {
   }
 
   # network
-  network_interface_ids = [element(azurerm_network_interface.controllers.*.id, count.index)]
+  network_interface_ids = [azurerm_network_interface.controllers.*.id[count.index]]
 
   os_profile {
     computer_name  = "${var.cluster_name}-controller-${count.index}"
     admin_username = "core"
-    custom_data    = element(data.ct_config.controller-ignitions.*.rendered, count.index)
+    custom_data    = data.ct_config.controller-ignitions.*.rendered[count.index]
   }
 
   # Azure mandates setting an ssh_key, even though Ignition custom_data handles it too
@@ -108,7 +105,7 @@ resource "azurerm_network_interface" "controllers" {
     private_ip_address_allocation = "dynamic"
 
     # public IPv4
-    public_ip_address_id = element(azurerm_public_ip.controllers.*.id, count.index)
+    public_ip_address_id = azurerm_public_ip.controllers.*.id[count.index]
   }
 }
 
@@ -134,11 +131,8 @@ resource "azurerm_public_ip" "controllers" {
 
 # Controller Ignition configs
 data "ct_config" "controller-ignitions" {
-  count = var.controller_count
-  content = element(
-    data.template_file.controller-configs.*.rendered,
-    count.index,
-  )
+  count        = var.controller_count
+  content      = data.template_file.controller-configs.*.rendered[count.index]
   pretty_print = false
   snippets     = var.controller_clc_snippets
 }
@@ -147,7 +141,7 @@ data "ct_config" "controller-ignitions" {
 data "template_file" "controller-configs" {
   count = var.controller_count
 
-  template = file("${path.module}/cl/controller.yaml.tmpl")
+  template = file("${path.module}/cl/controller.yaml")
 
   vars = {
     # Cannot use cyclic dependencies on controllers or their DNS records

azure/container-linux/kubernetes/ssh.tf

@@ -2,7 +2,7 @@ locals {
   # format assets for distribution
   assets_bundle = [
     # header with the unpack location
-    for key, value in module.bootstrap.assets_dist:
+    for key, value in module.bootstrap.assets_dist :
     format("##### %s\n%s", key, value)
   ]
 }
@@ -22,7 +22,7 @@ resource "null_resource" "copy-controller-secrets" {
     user    = "core"
     timeout = "15m"
   }
-  
+
   provisioner "file" {
     content     = join("\n", local.assets_bundle)
     destination = "$HOME/assets"
@@ -45,7 +45,7 @@ resource "null_resource" "bootstrap" {
 
   connection {
     type    = "ssh"
-    host    = element(azurerm_public_ip.controllers.*.ip_address, 0)
+    host    = azurerm_public_ip.controllers.*.ip_address[0]
     user    = "core"
     timeout = "15m"
   }

azure/container-linux/kubernetes/workers/workers.tf

@@ -1,7 +1,7 @@
 locals {
   # Channel for a Container Linux derivative
   # coreos-stable -> Container Linux Stable
-  channel = element(split("-", var.os_image), 1)
+  channel = split("-", var.os_image)[1]
 }
 
 # Workers scale set
@@ -104,7 +104,7 @@ data "ct_config" "worker-ignition" {
 
 # Worker Container Linux configs
 data "template_file" "worker-config" {
-  template = file("${path.module}/cl/worker.yaml.tmpl")
+  template = file("${path.module}/cl/worker.yaml")
 
   vars = {
     kubeconfig             = indent(10, var.kubeconfig)