Set the Google Cloud minimum CPU platform to Intel Haswell

* Intel Haswell or better is available in every zone around the world
* Neither Kubernetes nor Typhoon have a particular minimum processor
family. However, a few Google Cloud zones still default to Sandy/Ivy
bridge (scheduled to shift April 2019). Price is only based on machine
type so it is beneficial to opt for the next processor family
* Intel Haswell is a suitable minimum since it still allows plenty of
liberty in choosing any region or machine type
* Likely a slight increase to preemption probability in a few zones,
but any lower probability on Sandy/Ivy bridge is due to lower
desirability as they're phased out
* https://cloud.google.com/compute/docs/regions-zones/

CHANGES.md

@@ -11,6 +11,12 @@ Notable changes between versions.
 
 * Recommend updating [terraform-provider-matchbox](https://github.com/coreos/terraform-provider-matchbox) plugin from v0.2.2 to [v0.2.3](https://github.com/coreos/terraform-provider-matchbox/releases/tag/v0.2.3) ([#402](https://github.com/poseidon/typhoon/pull/402))
 
+#### Google Cloud
+
+* Set the minimum CPU platform to Intel Haswell ([#405](https://github.com/poseidon/typhoon/pull/405))
+  * Haswell or better is available in every zone (no price change)
+  * A few zones still default to Sandy/Ivy Bridge (shifts in April 2019)
+
 #### Addons
 
 * Improve Prometheus rules and alerts ([#404](https://github.com/poseidon/typhoon/pull/404))

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

@@ -34,6 +34,7 @@ resource "google_compute_instance" "controllers" {
   name             = "${var.cluster_name}-controller-${count.index}"
   zone             = "${element(local.zones, count.index)}"
   machine_type     = "${var.controller_type}"
+  min_cpu_platform = "Intel Haswell"
 
   metadata {
     user-data = "${element(data.ct_config.controller-ignitions.*.rendered, count.index)}"

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

@@ -26,6 +26,7 @@ resource "google_compute_instance_template" "worker" {
   name_prefix      = "${var.name}-worker-"
   description      = "Worker Instance template"
   machine_type     = "${var.machine_type}"
+  min_cpu_platform = "Intel Haswell"
 
   metadata {
     user-data = "${data.ct_config.worker-ignition.rendered}"

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

@@ -34,6 +34,7 @@ resource "google_compute_instance" "controllers" {
   name             = "${var.cluster_name}-controller-${count.index}"
   zone             = "${element(local.zones, count.index)}"
   machine_type     = "${var.controller_type}"
+  min_cpu_platform = "Intel Haswell"
 
   metadata {
     user-data = "${element(data.template_file.controller-cloudinit.*.rendered, count.index)}"

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

@@ -26,6 +26,7 @@ resource "google_compute_instance_template" "worker" {
   name_prefix      = "${var.name}-worker-"
   description      = "Worker Instance template"
   machine_type     = "${var.machine_type}"
+  min_cpu_platform = "Intel Haswell"
 
   metadata {
     user-data = "${data.template_file.worker-cloudinit.rendered}"