Add enable_aggregation option (defaults to false)

* Add an `enable_aggregation` variable to enable the kube-apiserver
aggregation layer for adding extension apiservers to clusters
* Aggregation is **disabled** by default. Typhoon recommends you not
enable aggregation. Consider whether less invasive ways to achieve your
goals are possible and whether those goals are well-founded
* Enabling aggregation and extension apiservers increases the attack
surface of a cluster and makes extensions a part of the control plane.
Admins must scrutinize and trust any extension apiserver used.
* Passing a v1.14 CNCF conformance test requires aggregation be enabled.
Having an option for aggregation keeps compliance, but retains the
stricter security posture on default clusters

CHANGES.md

@@ -6,6 +6,9 @@ Notable changes between versions.
 
 * Kubernetes [v1.14.0](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.14.md#v1140)
 * Update Calico from v3.6.0 to v3.6.1
+* Add `enable_aggregation` option for CNCF conformance
+  * Aggregation is disabled by default to retain our security stance
+  * Aggregation increases the security surface area. Extensions become part of the control plane and must be scrutinized carefully and trusted. Favor leaving aggregation disabled.
 
 #### AWS
 

aws/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]
@@ -12,4 +12,5 @@ module "bootkube" {
   service_cidr          = "${var.service_cidr}"
   cluster_domain_suffix = "${var.cluster_domain_suffix}"
   enable_reporting      = "${var.enable_reporting}"
+  enable_aggregation    = "${var.enable_aggregation}"
 }

aws/container-linux/kubernetes/variables.tf

@@ -146,3 +146,9 @@ variable "enable_reporting" {
   description = "Enable usage or analytics reporting to upstreams (Calico)"
   default     = "false"
 }
+
+variable "enable_aggregation" {
+  description = "Enable the Kubernetes Aggregation Layer (defaults to false)"
+  type        = "string"
+  default     = "false"
+}

aws/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]

azure/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]
@@ -11,4 +11,5 @@ module "bootkube" {
   service_cidr          = "${var.service_cidr}"
   cluster_domain_suffix = "${var.cluster_domain_suffix}"
   enable_reporting      = "${var.enable_reporting}"
+  enable_aggregation    = "${var.enable_aggregation}"
 }

azure/container-linux/kubernetes/variables.tf

@@ -121,3 +121,9 @@ variable "enable_reporting" {
   description = "Enable usage or analytics reporting to upstreams (Calico)"
   default     = "false"
 }
+
+variable "enable_aggregation" {
+  description = "Enable the Kubernetes Aggregation Layer (defaults to false)"
+  type        = "string"
+  default     = "false"
+}

bare-metal/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name                    = "${var.cluster_name}"
   api_servers                     = ["${var.k8s_domain_name}"]
@@ -13,4 +13,5 @@ module "bootkube" {
   service_cidr                    = "${var.service_cidr}"
   cluster_domain_suffix           = "${var.cluster_domain_suffix}"
   enable_reporting                = "${var.enable_reporting}"
+  enable_aggregation              = "${var.enable_aggregation}"
 }

bare-metal/container-linux/kubernetes/variables.tf

@@ -153,3 +153,9 @@ variable "enable_reporting" {
   description = "Enable usage or analytics reporting to upstreams (Calico)"
   default     = "false"
 }
+
+variable "enable_aggregation" {
+  description = "Enable the Kubernetes Aggregation Layer (defaults to false)"
+  type        = "string"
+  default     = "false"
+}

bare-metal/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${var.k8s_domain_name}"]

digital-ocean/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]
@@ -12,4 +12,5 @@ module "bootkube" {
   service_cidr          = "${var.service_cidr}"
   cluster_domain_suffix = "${var.cluster_domain_suffix}"
   enable_reporting      = "${var.enable_reporting}"
+  enable_aggregation    = "${var.enable_aggregation}"
 }

digital-ocean/container-linux/kubernetes/network.tf

@@ -96,4 +96,3 @@ resource "digitalocean_firewall" "workers" {
     },
   ]
 }
-

digital-ocean/container-linux/kubernetes/outputs.tf

@@ -38,4 +38,3 @@ output "worker_tag" {
   description = "Tag applied to worker droplets"
   value       = "${digitalocean_tag.workers.name}"
 }
-

digital-ocean/container-linux/kubernetes/variables.tf

@@ -98,3 +98,9 @@ variable "enable_reporting" {
   description = "Enable usage or analytics reporting to upstreams (Calico)"
   default     = "false"
 }
+
+variable "enable_aggregation" {
+  description = "Enable the Kubernetes Aggregation Layer (defaults to false)"
+  type        = "string"
+  default     = "false"
+}

digital-ocean/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]

google-cloud/container-linux/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]
@@ -12,6 +12,7 @@ module "bootkube" {
   service_cidr          = "${var.service_cidr}"
   cluster_domain_suffix = "${var.cluster_domain_suffix}"
   enable_reporting      = "${var.enable_reporting}"
+  enable_aggregation    = "${var.enable_aggregation}"
 
   // temporary
   apiserver_port = 443

google-cloud/container-linux/kubernetes/variables.tf

@@ -121,3 +121,9 @@ variable "enable_reporting" {
   description = "Enable usage or analytics reporting to upstreams (Calico)"
   default     = "false"
 }
+
+variable "enable_aggregation" {
+  description = "Enable the Kubernetes Aggregation Layer (defaults to false)"
+  type        = "string"
+  default     = "false"
+}

google-cloud/fedora-atomic/kubernetes/bootkube.tf

@@ -1,6 +1,6 @@
 # Self-hosted Kubernetes assets (kubeconfig, manifests)
 module "bootkube" {
-  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=ce5db83663b1de2096afc1787c2b622bc08987b3"
+  source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=feb6e4cb3e479b20dfc269f65e76ceb62d8d2ec4"
 
   cluster_name          = "${var.cluster_name}"
   api_servers           = ["${format("%s.%s", var.cluster_name, var.dns_zone)}"]