typhoon/google-cloud/flatcar-linux/kubernetes/apiserver.tf
Dalton Hubble 20b76d6e00 Roll instance template changes to worker managed instance groups
* When a worker managed instance group's (MIG) instance template
changes (including machine type, disk size, or Butane snippets
but excluding new AMIs), use Google Cloud's rolling update features
to ensure instances match declared state
* Ignore new AMIs since Fedora CoreOS and Flatcar Linux nodes
already auto-update and reboot themselves
* Rolling updates will create surge instances, wait for health
checks, then delete old instances (0 unavilable instances)
* Instances are replaced to ensure new Ignition/Butane snippets
are respected
* Add managed instance group autohealing (i.e. health checks) to
ensure new instances' Kubelet is running

Renames

* Name apiserver and kubelet health checks consistently
* Rename MIG from `${var.name}-worker-group` to `${var.name}-worker`

Rel: https://cloud.google.com/compute/docs/instance-groups/rolling-out-updates-to-managed-instance-groups
2022-08-14 13:06:53 -07:00

94 lines
2.7 KiB
HCL

# TCP Proxy load balancer DNS record
resource "google_dns_record_set" "apiserver" {
# DNS Zone name where record should be created
managed_zone = var.dns_zone_name
# DNS record
name = format("%s.%s.", var.cluster_name, var.dns_zone)
type = "A"
ttl = 300
# IPv4 address of apiserver TCP Proxy load balancer
rrdatas = [google_compute_global_address.apiserver-ipv4.address]
}
# Static IPv4 address for the TCP Proxy Load Balancer
resource "google_compute_global_address" "apiserver-ipv4" {
name = "${var.cluster_name}-apiserver-ip"
ip_version = "IPV4"
}
# Forward IPv4 TCP traffic to the TCP proxy load balancer
resource "google_compute_global_forwarding_rule" "apiserver" {
name = "${var.cluster_name}-apiserver"
ip_address = google_compute_global_address.apiserver-ipv4.address
ip_protocol = "TCP"
port_range = "443"
target = google_compute_target_tcp_proxy.apiserver.self_link
}
# Global TCP Proxy Load Balancer for apiservers
resource "google_compute_target_tcp_proxy" "apiserver" {
name = "${var.cluster_name}-apiserver"
description = "Distribute TCP load across ${var.cluster_name} controllers"
backend_service = google_compute_backend_service.apiserver.self_link
}
# Global backend service backed by unmanaged instance groups
resource "google_compute_backend_service" "apiserver" {
name = "${var.cluster_name}-apiserver"
description = "${var.cluster_name} apiserver service"
protocol = "TCP"
port_name = "apiserver"
session_affinity = "NONE"
timeout_sec = "300"
# controller(s) spread across zonal instance groups
dynamic "backend" {
for_each = google_compute_instance_group.controllers
content {
group = backend.value.self_link
}
}
health_checks = [google_compute_health_check.apiserver.self_link]
}
# Instance group of heterogeneous (unmanged) controller instances
resource "google_compute_instance_group" "controllers" {
count = min(var.controller_count, length(local.zones))
name = format("%s-controllers-%s", var.cluster_name, element(local.zones, count.index))
zone = element(local.zones, count.index)
named_port {
name = "apiserver"
port = "6443"
}
# add instances in the zone into the instance group
instances = matchkeys(
google_compute_instance.controllers.*.self_link,
google_compute_instance.controllers.*.zone,
[element(local.zones, count.index)],
)
}
# Health check for kube-apiserver
resource "google_compute_health_check" "apiserver" {
name = "${var.cluster_name}-apiserver-health"
description = "Health check for kube-apiserver"
timeout_sec = 5
check_interval_sec = 5
healthy_threshold = 1
unhealthy_threshold = 3
ssl_health_check {
port = "6443"
}
}