fix(misc): contrib/terraform/aws (#7818)

* fix(misc): terraform/aws

- handles deployment with a single availability zone
- handles deployment with more than two availability zone
- handles etcd collocation with control-plane nodes (`aws_etcd_num=0`)
- allows to set a bastion instances count (`aws_bastion_num`)
- allows to set bastion/etcd/control-plane/workers rootfs volume size
- removes variables from terraform.tfvars that were not re-used
- adds .terraform.lock.hcl to .gitignore
- changes/updates base image from ubuntu-18.03 to debian-10

tested by a few coworkers of mine, and myself: thanks for the outstanding
work, on both those terraform samples and kubespray playbooks.
I did not test ubuntu deployments, I could still swap from buster to
focal. LMK.

* fix(gitlab-ci)

AFAIU, terraform.tfvars indentation should be fixed for / no diff
returned running `terraform fmt -check -diff`

https://gitlab.com/kargo-ci/kubernetes-sigs-kubespray/-/jobs/1445622114

contrib/terraform/aws/variables.tf

@@ -25,7 +25,7 @@ data "aws_ami" "distro" {
 
   filter {
     name   = "name"
-    values = ["ubuntu/images/hvm-ssd/ubuntu-bionic-18.04-amd64-server-*"]
+    values = ["debian-10-amd64-*"]
   }
 
   filter {
@@ -33,7 +33,7 @@ data "aws_ami" "distro" {
     values = ["hvm"]
   }
 
-  owners = ["099720109477"] # Canonical
+  owners = ["136693071363"] # Debian-10
 }
 
 //AWS VPC Variables
@@ -63,10 +63,18 @@ variable "aws_bastion_size" {
 * The number should be divisable by the number of used
 * AWS Availability Zones without an remainder.
 */
+variable "aws_bastion_num" {
+  description = "Number of Bastion Nodes"
+}
+
 variable "aws_kube_master_num" {
   description = "Number of Kubernetes Master Nodes"
 }
 
+variable "aws_kube_master_disk_size" {
+  description = "Disk size for Kubernetes Master Nodes (in GiB)"
+}
+
 variable "aws_kube_master_size" {
   description = "Instance size of Kube Master Nodes"
 }
@@ -75,6 +83,10 @@ variable "aws_etcd_num" {
   description = "Number of etcd Nodes"
 }
 
+variable "aws_etcd_disk_size" {
+  description = "Disk size for etcd Nodes (in GiB)"
+}
+
 variable "aws_etcd_size" {
   description = "Instance size of etcd Nodes"
 }
@@ -83,6 +95,10 @@ variable "aws_kube_worker_num" {
   description = "Number of Kubernetes Worker Nodes"
 }
 
+variable "aws_kube_worker_disk_size" {
+  description = "Disk size for Kubernetes Worker Nodes (in GiB)"
+}
+
 variable "aws_kube_worker_size" {
   description = "Instance size of Kubernetes Worker Nodes"
 }