Add small CPU resource requests to static pods

* Set small CPU requests on static pods kube-apiserver,
kube-controller-manager, and kube-scheduler to align with
upstream tooling and for edge cases
* Effectively, a practical case for these requests hasn't been
observed. However, a small static pod CPU request may offer
a slight benefit if a controller became overloaded and the
below mechanisms were insufficient for some reason (bit of a
stretch, due to CPU compressibility)

Existing safeguards:

* Control plane nodes are tainted to isolate them from
ordinary workloads. Even dense workloads can only compress
CPU resources on worker nodes.
* Control plane static pods use the highest priority class, so
contention favors control plane pods (over say node-exporter)
and CPU is compressible too.

See: poseidon/terraform-render-bootstrap#161

Author: dghubble

CHANGES.md

@@ -6,6 +6,8 @@ Notable changes between versions.
 
 * Update CoreDNS from v1.6.2 to v1.6.5 ([#588](https://github.com/poseidon/typhoon/pull/588))
   * Add health `lameduck` option to wait before shutdown
+* Add CPU requests to control plane static pods ([#589](https://github.com/poseidon/typhoon/pull/589))
+  * May provide slight edge case benefits and aligns with upstream
 * Replace usage of `template_dir` with `templatefile` function ([#587](https://github.com/poseidon/typhoon/pull/587))
   * Require Terraform version v0.12.6+ (action required)
 

aws/container-linux/kubernetes/bootstrap.tf

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name          = var.cluster_name
   api_servers           = [format("%s.%s", var.cluster_name, var.dns_zone)]

aws/fedora-coreos/kubernetes/bootstrap.tf

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name          = var.cluster_name
   api_servers           = [format("%s.%s", var.cluster_name, var.dns_zone)]

azure/container-linux/kubernetes/bootstrap.tf

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name = var.cluster_name
   api_servers  = [format("%s.%s", var.cluster_name, var.dns_zone)]

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

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name                    = var.cluster_name
   api_servers                     = [var.k8s_domain_name]

bare-metal/fedora-coreos/kubernetes/bootstrap.tf

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name                    = var.cluster_name
   api_servers                     = [var.k8s_domain_name]

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

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name = var.cluster_name
   api_servers  = [format("%s.%s", var.cluster_name, var.dns_zone)]

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

@@ -1,6 +1,6 @@
 # Kubernetes assets (kubeconfig, manifests)
 module "bootstrap" {
-  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref=43e1230c550b1456f13bd0df199164139dfbfba7"
+  source = "git::https://github.com/poseidon/terraform-render-bootstrap.git?ref="
 
   cluster_name          = var.cluster_name
   api_servers           = [format("%s.%s", var.cluster_name, var.dns_zone)]