Migrate Flatcar Linux from Ignition spec v2.3.0 to v3.3.0

* Requires poseidon v0.11+ and Flatcar Linux 3185.0.0+ (action required)
* Previously, Flatcar Linux configs have been parsed as Container
Linux Configs to Ignition v2.2.0 specs by poseidon/ct
* Flatcar Linux starting in 3185.0.0 now supports Ignition v3.x specs
(which are rendered from Butane Configs, like Fedora CoreOS)
* poseidon/ct v0.11.0 adds support for the flatcar Butane Config
variant so that Flatcar Linux can use Ignition v3.x

Rel:

* [Flatcar Support](https://flatcar-linux.org/docs/latest/provisioning/ignition/specification/#ignition-v3)
* [poseidon/ct support](https://github.com/poseidon/terraform-provider-ct/pull/131)

aws/flatcar-linux/kubernetes/workers/butane/worker.yaml

@@ -1,4 +1,5 @@
----
+variant: flatcar
+version: 1.0.0
 systemd:
   units:
     - name: docker.service
@@ -106,13 +107,11 @@ systemd:
 storage:
   files:
     - path: /etc/kubernetes/kubeconfig
-      filesystem: root
       mode: 0644
       contents:
         inline: |
           ${kubeconfig}
     - path: /etc/sysctl.d/max-user-watches.conf
-      filesystem: root
       mode: 0644
       contents:
         inline: |

aws/flatcar-linux/kubernetes/workers/versions.tf

@@ -6,7 +6,7 @@ terraform {
     aws = ">= 2.23, <= 5.0"
     ct = {
       source  = "poseidon/ct"
-      version = "~> 0.9"
+      version = "~> 0.11"
     }
   }
 }

aws/flatcar-linux/kubernetes/workers/workers.tf

@@ -69,7 +69,7 @@ resource "aws_launch_configuration" "worker" {
 
 # Flatcar Linux worker
 data "ct_config" "worker" {
-  content = templatefile("${path.module}/cl/worker.yaml", {
+  content = templatefile("${path.module}/butane/worker.yaml", {
     kubeconfig             = indent(10, var.kubeconfig)
     ssh_authorized_key     = var.ssh_authorized_key
     cluster_dns_service_ip = cidrhost(var.service_cidr, 10)