Add support for worker pools on AWS

* Allow groups of workers to be defined and joined to
a cluster (i.e. worker pools)
* Move worker resources into a Terraform submodule
* Output variables needed for passing to worker pools
* Add usage docs for AWS worker pools (advanced)

CHANGES.md

@@ -4,10 +4,11 @@ Notable changes between versions.
 
 ## Latest
 
+* Add [worker pools](https://typhoon.psdn.io/advanced/worker-pools/) for AWS and Google Cloud (advanced)
+* [Recommend](https://typhoon.psdn.io/topics/maintenance/#terraform-provider-ct-v021) updating `terraform-provider-ct` plugin from v0.2.0 to [v0.2.1](https://github.com/coreos/terraform-provider-ct/releases/tag/v0.2.1) (action recommended)
 * Upgrade etcd from v3.2.15 to v3.3.1
 * Update Calico from v3.0.2 to v3.0.3
 * Use kubernetes-incubator/bootkube v0.10.0
-* [Recommend](https://typhoon.psdn.io/topics/maintenance/#terraform-provider-ct-v021) updating `terraform-provider-ct` plugin from v0.2.0 to [v0.2.1](https://github.com/coreos/terraform-provider-ct/releases/tag/v0.2.1) (action recommended)
 
 #### AWS
 
@@ -15,6 +16,7 @@ Notable changes between versions.
 * Switch Ingress elastic load balancer to a network load balancer ([#141](https://github.com/poseidon/typhoon/pull/141))
   * AWS [NLBs](https://aws.amazon.com/blogs/aws/new-network-load-balancer-effortless-scaling-to-millions-of-requests-per-second/) can handle millions of RPS with high throughput and low latency.
   * Require terraform-provider-aws 1.7.0 or higher
+* Allow groups of workers to be defined and joined to a cluster (i.e. worker pools) ([#150](https://github.com/poseidon/typhoon/pull/150))
 * Add kubelet `--volume-plugin-dir` flag to allow flexvolume plugins ([#142](https://github.com/poseidon/typhoon/pull/142))
 
 #### Digital Ocean
@@ -24,7 +26,7 @@ Notable changes between versions.
 
 #### Google Cloud
 
-* Add support for "worker pools" - groups of homogeneous workers joined to an existing cluster ([#148](https://github.com/poseidon/typhoon/pull/148))
+* Allow groups of workers to be defined and joined to a cluster (i.e. worker pools) ([#148](https://github.com/poseidon/typhoon/pull/148))
 * Add kubelet `--volume-plugin-dir` flag to allow flexvolume plugins ([#142](https://github.com/poseidon/typhoon/pull/142))
 * Add `kubeconfig` variable to `controllers` and `workers` submodules ([#147](https://github.com/poseidon/typhoon/pull/147))
 * Remove `kubeconfig_*` variables from `controllers` and `workers` submodules ([#147](https://github.com/poseidon/typhoon/pull/147))

README.md

@@ -14,6 +14,7 @@ Typhoon distributes upstream Kubernetes, architectural conventions, and cluster
 * Kubernetes v1.9.3 (upstream, via [kubernetes-incubator/bootkube](https://github.com/kubernetes-incubator/bootkube))
 * Single or multi-master, workloads isolated on workers, [Calico](https://www.projectcalico.org/) or [flannel](https://github.com/coreos/flannel) networking
 * On-cluster etcd with TLS, [RBAC](https://kubernetes.io/docs/admin/authorization/rbac/)-enabled, [network policy](https://kubernetes.io/docs/concepts/services-networking/network-policies/)
+* Advanced features like [worker pools](https://typhoon.psdn.io/advanced/worker-pools/) and [preemption](https://typhoon.psdn.io/google-cloud/#preemption) (varies by platform)
 * Ready for Ingress, Dashboards, Metrics, and other optional [addons](https://typhoon.psdn.io/addons/overview/)
 
 ## Modules

aws/container-linux/kubernetes/README.md

@@ -14,6 +14,7 @@ Typhoon distributes upstream Kubernetes, architectural conventions, and cluster
 * Kubernetes v1.9.3 (upstream, via [kubernetes-incubator/bootkube](https://github.com/kubernetes-incubator/bootkube))
 * Single or multi-master, workloads isolated on workers, [Calico](https://www.projectcalico.org/) or [flannel](https://github.com/coreos/flannel) networking
 * On-cluster etcd with TLS, [RBAC](https://kubernetes.io/docs/admin/authorization/rbac/)-enabled, [network policy](https://kubernetes.io/docs/concepts/services-networking/network-policies/)
+* Advanced features like [worker pools](https://typhoon.psdn.io/advanced/worker-pools/)
 * Ready for Ingress, Dashboards, Metrics, and other optional [addons](https://typhoon.psdn.io/addons/overview/)
 
 ## Docs

aws/container-linux/kubernetes/controllers.tf

@@ -79,185 +79,3 @@ data "ct_config" "controller_ign" {
   content      = "${element(data.template_file.controller_config.*.rendered, count.index)}"
   pretty_print = false
 }
-
-# Security Group (instance firewall)
-
-resource "aws_security_group" "controller" {
-  name        = "${var.cluster_name}-controller"
-  description = "${var.cluster_name} controller security group"
-
-  vpc_id = "${aws_vpc.network.id}"
-
-  tags = "${map("Name", "${var.cluster_name}-controller")}"
-}
-
-resource "aws_security_group_rule" "controller-icmp" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type        = "ingress"
-  protocol    = "icmp"
-  from_port   = 0
-  to_port     = 0
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "controller-ssh" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type        = "ingress"
-  protocol    = "tcp"
-  from_port   = 22
-  to_port     = 22
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "controller-apiserver" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type        = "ingress"
-  protocol    = "tcp"
-  from_port   = 443
-  to_port     = 443
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "controller-etcd" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 2379
-  to_port   = 2380
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-flannel" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type                     = "ingress"
-  protocol                 = "udp"
-  from_port                = 8472
-  to_port                  = 8472
-  source_security_group_id = "${aws_security_group.worker.id}"
-}
-
-resource "aws_security_group_rule" "controller-flannel-self" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = "udp"
-  from_port = 8472
-  to_port   = 8472
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-node-exporter" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type                     = "ingress"
-  protocol                 = "tcp"
-  from_port                = 9100
-  to_port                  = 9100
-  source_security_group_id = "${aws_security_group.worker.id}"
-}
-
-resource "aws_security_group_rule" "controller-kubelet-self" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 10250
-  to_port   = 10250
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-kubelet-read" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type                     = "ingress"
-  protocol                 = "tcp"
-  from_port                = 10255
-  to_port                  = 10255
-  source_security_group_id = "${aws_security_group.worker.id}"
-}
-
-resource "aws_security_group_rule" "controller-kubelet-read-self" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 10255
-  to_port   = 10255
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-bgp" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type                     = "ingress"
-  protocol                 = "tcp"
-  from_port                = 179
-  to_port                  = 179
-  source_security_group_id = "${aws_security_group.worker.id}"
-}
-
-resource "aws_security_group_rule" "controller-bgp-self" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 179
-  to_port   = 179
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-ipip" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type                     = "ingress"
-  protocol                 = 4
-  from_port                = 0
-  to_port                  = 0
-  source_security_group_id = "${aws_security_group.worker.id}"
-}
-
-resource "aws_security_group_rule" "controller-ipip-self" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = 4
-  from_port = 0
-  to_port   = 0
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-ipip-legacy" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type                     = "ingress"
-  protocol                 = 94
-  from_port                = 0
-  to_port                  = 0
-  source_security_group_id = "${aws_security_group.worker.id}"
-}
-
-resource "aws_security_group_rule" "controller-ipip-legacy-self" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type      = "ingress"
-  protocol  = 94
-  from_port = 0
-  to_port   = 0
-  self      = true
-}
-
-resource "aws_security_group_rule" "controller-egress" {
-  security_group_id = "${aws_security_group.controller.id}"
-
-  type             = "egress"
-  protocol         = "-1"
-  from_port        = 0
-  to_port          = 0
-  cidr_blocks      = ["0.0.0.0/0"]
-  ipv6_cidr_blocks = ["::/0"]
-}

aws/container-linux/kubernetes/outputs.tf

@@ -1,4 +1,25 @@
 output "ingress_dns_name" {
-  value       = "${aws_lb.ingress.dns_name}"
+  value       = "${module.workers.ingress_dns_name}"
   description = "DNS name of the network load balancer for distributing traffic to Ingress controllers"
 }
+
+# Outputs for worker pools
+
+output "vpc_id" {
+  value = "${aws_vpc.network.id}"
+  description = "ID of the VPC for creating worker instances"
+}
+
+output "subnet_ids" {
+  value = ["${aws_subnet.public.*.id}"]
+  description = "List of subnet IDs for creating worker instances"
+}
+
+output "worker_security_groups" {
+  value = ["${aws_security_group.worker.id}"]
+  description = "List of worker security group IDs"
+}
+
+output "kubeconfig" {
+  value = "${module.bootkube.kubeconfig}"
+}

aws/container-linux/kubernetes/security.tf

@@ -0,0 +1,385 @@
+# Security Groups (instance firewalls)
+
+# Controller security group
+
+resource "aws_security_group" "controller" {
+  name        = "${var.cluster_name}-controller"
+  description = "${var.cluster_name} controller security group"
+
+  vpc_id = "${aws_vpc.network.id}"
+
+  tags = "${map("Name", "${var.cluster_name}-controller")}"
+}
+
+resource "aws_security_group_rule" "controller-icmp" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type        = "ingress"
+  protocol    = "icmp"
+  from_port   = 0
+  to_port     = 0
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "controller-ssh" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type        = "ingress"
+  protocol    = "tcp"
+  from_port   = 22
+  to_port     = 22
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "controller-apiserver" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type        = "ingress"
+  protocol    = "tcp"
+  from_port   = 443
+  to_port     = 443
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "controller-etcd" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 2379
+  to_port   = 2380
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-flannel" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type                     = "ingress"
+  protocol                 = "udp"
+  from_port                = 8472
+  to_port                  = 8472
+  source_security_group_id = "${aws_security_group.worker.id}"
+}
+
+resource "aws_security_group_rule" "controller-flannel-self" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = "udp"
+  from_port = 8472
+  to_port   = 8472
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-node-exporter" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type                     = "ingress"
+  protocol                 = "tcp"
+  from_port                = 9100
+  to_port                  = 9100
+  source_security_group_id = "${aws_security_group.worker.id}"
+}
+
+resource "aws_security_group_rule" "controller-kubelet-self" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 10250
+  to_port   = 10250
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-kubelet-read" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type                     = "ingress"
+  protocol                 = "tcp"
+  from_port                = 10255
+  to_port                  = 10255
+  source_security_group_id = "${aws_security_group.worker.id}"
+}
+
+resource "aws_security_group_rule" "controller-kubelet-read-self" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 10255
+  to_port   = 10255
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-bgp" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type                     = "ingress"
+  protocol                 = "tcp"
+  from_port                = 179
+  to_port                  = 179
+  source_security_group_id = "${aws_security_group.worker.id}"
+}
+
+resource "aws_security_group_rule" "controller-bgp-self" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 179
+  to_port   = 179
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-ipip" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type                     = "ingress"
+  protocol                 = 4
+  from_port                = 0
+  to_port                  = 0
+  source_security_group_id = "${aws_security_group.worker.id}"
+}
+
+resource "aws_security_group_rule" "controller-ipip-self" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = 4
+  from_port = 0
+  to_port   = 0
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-ipip-legacy" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type                     = "ingress"
+  protocol                 = 94
+  from_port                = 0
+  to_port                  = 0
+  source_security_group_id = "${aws_security_group.worker.id}"
+}
+
+resource "aws_security_group_rule" "controller-ipip-legacy-self" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type      = "ingress"
+  protocol  = 94
+  from_port = 0
+  to_port   = 0
+  self      = true
+}
+
+resource "aws_security_group_rule" "controller-egress" {
+  security_group_id = "${aws_security_group.controller.id}"
+
+  type             = "egress"
+  protocol         = "-1"
+  from_port        = 0
+  to_port          = 0
+  cidr_blocks      = ["0.0.0.0/0"]
+  ipv6_cidr_blocks = ["::/0"]
+}
+
+# Worker security group
+
+resource "aws_security_group" "worker" {
+  name        = "${var.cluster_name}-worker"
+  description = "${var.cluster_name} worker security group"
+
+  vpc_id = "${aws_vpc.network.id}"
+
+  tags = "${map("Name", "${var.cluster_name}-worker")}"
+}
+
+resource "aws_security_group_rule" "worker-icmp" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type        = "ingress"
+  protocol    = "icmp"
+  from_port   = 0
+  to_port     = 0
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "worker-ssh" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type        = "ingress"
+  protocol    = "tcp"
+  from_port   = 22
+  to_port     = 22
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "worker-http" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type        = "ingress"
+  protocol    = "tcp"
+  from_port   = 80
+  to_port     = 80
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "worker-https" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type        = "ingress"
+  protocol    = "tcp"
+  from_port   = 443
+  to_port     = 443
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "worker-flannel" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type                     = "ingress"
+  protocol                 = "udp"
+  from_port                = 8472
+  to_port                  = 8472
+  source_security_group_id = "${aws_security_group.controller.id}"
+}
+
+resource "aws_security_group_rule" "worker-flannel-self" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = "udp"
+  from_port = 8472
+  to_port   = 8472
+  self      = true
+}
+
+resource "aws_security_group_rule" "worker-node-exporter" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 9100
+  to_port   = 9100
+  self      = true
+}
+
+resource "aws_security_group_rule" "ingress-health" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type        = "ingress"
+  protocol    = "tcp"
+  from_port   = 10254
+  to_port     = 10254
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_security_group_rule" "worker-kubelet" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type                     = "ingress"
+  protocol                 = "tcp"
+  from_port                = 10250
+  to_port                  = 10250
+  source_security_group_id = "${aws_security_group.controller.id}"
+}
+
+resource "aws_security_group_rule" "worker-kubelet-self" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 10250
+  to_port   = 10250
+  self      = true
+}
+
+resource "aws_security_group_rule" "worker-kubelet-read" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type                     = "ingress"
+  protocol                 = "tcp"
+  from_port                = 10255
+  to_port                  = 10255
+  source_security_group_id = "${aws_security_group.controller.id}"
+}
+
+resource "aws_security_group_rule" "worker-kubelet-read-self" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 10255
+  to_port   = 10255
+  self      = true
+}
+
+resource "aws_security_group_rule" "worker-bgp" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type                     = "ingress"
+  protocol                 = "tcp"
+  from_port                = 179
+  to_port                  = 179
+  source_security_group_id = "${aws_security_group.controller.id}"
+}
+
+resource "aws_security_group_rule" "worker-bgp-self" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = "tcp"
+  from_port = 179
+  to_port   = 179
+  self      = true
+}
+
+resource "aws_security_group_rule" "worker-ipip" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type                     = "ingress"
+  protocol                 = 4
+  from_port                = 0
+  to_port                  = 0
+  source_security_group_id = "${aws_security_group.controller.id}"
+}
+
+resource "aws_security_group_rule" "worker-ipip-self" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = 4
+  from_port = 0
+  to_port   = 0
+  self      = true
+}
+
+resource "aws_security_group_rule" "worker-ipip-legacy" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type                     = "ingress"
+  protocol                 = 94
+  from_port                = 0
+  to_port                  = 0
+  source_security_group_id = "${aws_security_group.controller.id}"
+}
+
+resource "aws_security_group_rule" "worker-ipip-legacy-self" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type      = "ingress"
+  protocol  = 94
+  from_port = 0
+  to_port   = 0
+  self      = true
+}
+
+resource "aws_security_group_rule" "worker-egress" {
+  security_group_id = "${aws_security_group.worker.id}"
+
+  type             = "egress"
+  protocol         = "-1"
+  from_port        = 0
+  to_port          = 0
+  cidr_blocks      = ["0.0.0.0/0"]
+  ipv6_cidr_blocks = ["::/0"]
+}

aws/container-linux/kubernetes/workers.tf

@@ -1,276 +1,19 @@
-# Workers AutoScaling Group
+module "workers" {
-resource "aws_autoscaling_group" "workers" {
+  source = "workers"
-  name = "${var.cluster_name}-worker ${aws_launch_configuration.worker.name}"
+  cluster_name = "${var.cluster_name}"
   
-  # count
+  # AWS
-  desired_capacity          = "${var.worker_count}"
+  vpc_id      = "${aws_vpc.network.id}"
-  min_size                  = "${var.worker_count}"
+  subnet_ids = ["${aws_subnet.public.*.id}"]
-  max_size                  = "${var.worker_count + 2}"
-  default_cooldown          = 30
-  health_check_grace_period = 30
-
-  # network
-  vpc_zone_identifier = ["${aws_subnet.public.*.id}"]
-
-  # template
-  launch_configuration = "${aws_launch_configuration.worker.name}"
-
-  # target groups to which instances should be added
-  target_group_arns = [
-    "${aws_lb_target_group.workers-http.id}",
-    "${aws_lb_target_group.workers-https.id}",
-  ]
-
-  lifecycle {
-    # override the default destroy and replace update behavior
-    create_before_destroy = true
-    ignore_changes        = ["image_id"]
-  }
-
-  tags = [{
-    key                 = "Name"
-    value               = "${var.cluster_name}-worker"
-    propagate_at_launch = true
-  }]
-}
-
-# Worker template
-resource "aws_launch_configuration" "worker" {
-  image_id      = "${data.aws_ami.coreos.image_id}"
-  instance_type = "${var.worker_type}"
-
-  user_data = "${data.ct_config.worker_ign.rendered}"
-
-  # storage
-  root_block_device {
-    volume_type = "standard"
-    volume_size = "${var.disk_size}"
-  }
-
-  # network
   security_groups = ["${aws_security_group.worker.id}"]
+  count = "${var.worker_count}"
+  instance_type = "${var.worker_type}"
+  os_channel = "${var.os_channel}"
+  disk_size = "${var.disk_size}"
 
-  lifecycle {
+  # configuration
-    // Override the default destroy and replace update behavior
+  kubeconfig = "${module.bootkube.kubeconfig}"
-    create_before_destroy = true
-  }
-}
-
-# Worker Container Linux Config
-data "template_file" "worker_config" {
-  template = "${file("${path.module}/cl/worker.yaml.tmpl")}"
-
-  vars = {
-    kubeconfig            = "${indent(10, module.bootkube.kubeconfig)}"
   ssh_authorized_key = "${var.ssh_authorized_key}"
-    k8s_dns_service_ip    = "${cidrhost(var.service_cidr, 10)}"
+  service_cidr = "${var.service_cidr}"
   cluster_domain_suffix = "${var.cluster_domain_suffix}"
 }
-}
-
-data "ct_config" "worker_ign" {
-  content      = "${data.template_file.worker_config.rendered}"
-  pretty_print = false
-}
-
-# Security Group (instance firewall)
-
-resource "aws_security_group" "worker" {
-  name        = "${var.cluster_name}-worker"
-  description = "${var.cluster_name} worker security group"
-
-  vpc_id = "${aws_vpc.network.id}"
-
-  tags = "${map("Name", "${var.cluster_name}-worker")}"
-}
-
-resource "aws_security_group_rule" "worker-icmp" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type        = "ingress"
-  protocol    = "icmp"
-  from_port   = 0
-  to_port     = 0
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "worker-ssh" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type        = "ingress"
-  protocol    = "tcp"
-  from_port   = 22
-  to_port     = 22
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "worker-http" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type        = "ingress"
-  protocol    = "tcp"
-  from_port   = 80
-  to_port     = 80
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "worker-https" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type        = "ingress"
-  protocol    = "tcp"
-  from_port   = 443
-  to_port     = 443
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "worker-flannel" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type                     = "ingress"
-  protocol                 = "udp"
-  from_port                = 8472
-  to_port                  = 8472
-  source_security_group_id = "${aws_security_group.controller.id}"
-}
-
-resource "aws_security_group_rule" "worker-flannel-self" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = "udp"
-  from_port = 8472
-  to_port   = 8472
-  self      = true
-}
-
-resource "aws_security_group_rule" "worker-node-exporter" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 9100
-  to_port   = 9100
-  self      = true
-}
-
-resource "aws_security_group_rule" "ingress-health" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type        = "ingress"
-  protocol    = "tcp"
-  from_port   = 10254
-  to_port     = 10254
-  cidr_blocks = ["0.0.0.0/0"]
-}
-
-resource "aws_security_group_rule" "worker-kubelet" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type                     = "ingress"
-  protocol                 = "tcp"
-  from_port                = 10250
-  to_port                  = 10250
-  source_security_group_id = "${aws_security_group.controller.id}"
-}
-
-resource "aws_security_group_rule" "worker-kubelet-self" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 10250
-  to_port   = 10250
-  self      = true
-}
-
-resource "aws_security_group_rule" "worker-kubelet-read" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type                     = "ingress"
-  protocol                 = "tcp"
-  from_port                = 10255
-  to_port                  = 10255
-  source_security_group_id = "${aws_security_group.controller.id}"
-}
-
-resource "aws_security_group_rule" "worker-kubelet-read-self" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 10255
-  to_port   = 10255
-  self      = true
-}
-
-resource "aws_security_group_rule" "worker-bgp" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type                     = "ingress"
-  protocol                 = "tcp"
-  from_port                = 179
-  to_port                  = 179
-  source_security_group_id = "${aws_security_group.controller.id}"
-}
-
-resource "aws_security_group_rule" "worker-bgp-self" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = "tcp"
-  from_port = 179
-  to_port   = 179
-  self      = true
-}
-
-resource "aws_security_group_rule" "worker-ipip" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type                     = "ingress"
-  protocol                 = 4
-  from_port                = 0
-  to_port                  = 0
-  source_security_group_id = "${aws_security_group.controller.id}"
-}
-
-resource "aws_security_group_rule" "worker-ipip-self" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = 4
-  from_port = 0
-  to_port   = 0
-  self      = true
-}
-
-resource "aws_security_group_rule" "worker-ipip-legacy" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type                     = "ingress"
-  protocol                 = 94
-  from_port                = 0
-  to_port                  = 0
-  source_security_group_id = "${aws_security_group.controller.id}"
-}
-
-resource "aws_security_group_rule" "worker-ipip-legacy-self" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type      = "ingress"
-  protocol  = 94
-  from_port = 0
-  to_port   = 0
-  self      = true
-}
-
-resource "aws_security_group_rule" "worker-egress" {
-  security_group_id = "${aws_security_group.worker.id}"
-
-  type             = "egress"
-  protocol         = "-1"
-  from_port        = 0
-  to_port          = 0
-  cidr_blocks      = ["0.0.0.0/0"]
-  ipv6_cidr_blocks = ["::/0"]
-}

aws/container-linux/kubernetes/workers/ami.tf

@@ -0,0 +1,19 @@
+data "aws_ami" "coreos" {
+  most_recent = true
+  owners      = ["595879546273"]
+
+  filter {
+    name   = "architecture"
+    values = ["x86_64"]
+  }
+
+  filter {
+    name   = "virtualization-type"
+    values = ["hvm"]
+  }
+
+  filter {
+    name   = "name"
+    values = ["CoreOS-${var.os_channel}-*"]
+  }
+}

aws/container-linux/kubernetes/workers/ingress.tf

@@ -4,7 +4,7 @@ resource "aws_lb" "ingress" {
   load_balancer_type = "network"
   internal           = false
 
-  subnets = ["${aws_subnet.public.*.id}"]
+  subnets = ["${var.subnet_ids}"]
 }
 
 # Forward HTTP traffic to workers
@@ -35,7 +35,7 @@ resource "aws_lb_listener" "ingress-https" {
 
 resource "aws_lb_target_group" "workers-http" {
   name        = "${var.cluster_name}-workers-http"
-  vpc_id      = "${aws_vpc.network.id}"
+  vpc_id      = "${var.vpc_id}"
   target_type = "instance"
 
   protocol = "TCP"
@@ -58,7 +58,7 @@ resource "aws_lb_target_group" "workers-http" {
 
 resource "aws_lb_target_group" "workers-https" {
   name        = "${var.cluster_name}-workers-https"
-  vpc_id      = "${aws_vpc.network.id}"
+  vpc_id      = "${var.vpc_id}"
   target_type = "instance"
 
   protocol = "TCP"

aws/container-linux/kubernetes/workers/outputs.tf

@@ -0,0 +1,4 @@
+output "ingress_dns_name" {
+  value       = "${aws_lb.ingress.dns_name}"
+  description = "DNS name of the network load balancer for distributing traffic to Ingress controllers"
+}

aws/container-linux/kubernetes/workers/variables.tf

@@ -0,0 +1,73 @@
+variable "cluster_name" {
+  type        = "string"
+  description = "Unique name"
+}
+
+variable "vpc_id" {
+  type = "string"
+  description = "ID of the VPC for creating instances"
+}
+
+variable "subnet_ids" {
+  type = "list"
+  description = "List of subnet IDs for creating instances"
+}
+
+variable "security_groups" {
+  type = "list"
+  description = "List of security group IDs"
+}
+
+# instances
+
+variable "count" {
+  type        = "string"
+  default     = "1"
+  description = "Number of instances"
+}
+
+variable "instance_type" {
+  type        = "string"
+  default     = "t2.small"
+  description = "EC2 instance type"
+}
+
+variable "os_channel" {
+  type        = "string"
+  default     = "stable"
+  description = "Container Linux AMI channel (stable, beta, alpha)"
+}
+
+variable "disk_size" {
+  type        = "string"
+  default     = "40"
+  description = "Size of the disk in GB"
+}
+
+# configuration
+
+variable "kubeconfig" {
+  type = "string"
+  description = "Generated Kubelet kubeconfig"
+}
+
+variable "ssh_authorized_key" {
+  type        = "string"
+  description = "SSH public key for user 'core'"
+}
+
+variable "service_cidr" {
+  description = <<EOD
+CIDR IPv4 range to assign Kubernetes services.
+The 1st IP will be reserved for kube_apiserver, the 10th IP will be reserved for kube-dns.
+EOD
+
+  type    = "string"
+  default = "10.3.0.0/16"
+}
+
+variable "cluster_domain_suffix" {
+  description = "Queries for domains with the suffix will be answered by kube-dns. Default is cluster.local (e.g. foo.default.svc.cluster.local) "
+  type        = "string"
+  default     = "cluster.local"
+}

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

@@ -0,0 +1,74 @@
+# Workers AutoScaling Group
+resource "aws_autoscaling_group" "workers" {
+  name = "${var.cluster_name}-worker ${aws_launch_configuration.worker.name}"
+
+  # count
+  desired_capacity          = "${var.count}"
+  min_size                  = "${var.count}"
+  max_size                  = "${var.count + 2}"
+  default_cooldown          = 30
+  health_check_grace_period = 30
+
+  # network
+  vpc_zone_identifier = ["${var.subnet_ids}"]
+
+  # template
+  launch_configuration = "${aws_launch_configuration.worker.name}"
+
+  # target groups to which instances should be added
+  target_group_arns = [
+    "${aws_lb_target_group.workers-http.id}",
+    "${aws_lb_target_group.workers-https.id}",
+  ]
+
+  lifecycle {
+    # override the default destroy and replace update behavior
+    create_before_destroy = true
+    ignore_changes        = ["image_id"]
+  }
+
+  tags = [{
+    key                 = "Name"
+    value               = "${var.cluster_name}-worker"
+    propagate_at_launch = true
+  }]
+}
+
+# Worker template
+resource "aws_launch_configuration" "worker" {
+  image_id      = "${data.aws_ami.coreos.image_id}"
+  instance_type = "${var.instance_type}"
+
+  user_data = "${data.ct_config.worker_ign.rendered}"
+
+  # storage
+  root_block_device {
+    volume_type = "standard"
+    volume_size = "${var.disk_size}"
+  }
+
+  # network
+  security_groups = ["${var.security_groups}"]
+
+  lifecycle {
+    // Override the default destroy and replace update behavior
+    create_before_destroy = true
+  }
+}
+
+# Worker Container Linux Config
+data "template_file" "worker_config" {
+  template = "${file("${path.module}/cl/worker.yaml.tmpl")}"
+
+  vars = {
+    kubeconfig            = "${indent(10, var.kubeconfig)}"
+    ssh_authorized_key    = "${var.ssh_authorized_key}"
+    k8s_dns_service_ip    = "${cidrhost(var.service_cidr, 10)}"
+    cluster_domain_suffix = "${var.cluster_domain_suffix}"
+  }
+}
+
+data "ct_config" "worker_ign" {
+  content      = "${data.template_file.worker_config.rendered}"
+  pretty_print = false
+}

docs/advanced/worker-pools.md

@@ -1,26 +1,97 @@
 # Worker Pools
 
-Typhoon can create "worker pools", groups of homogeneous workers that are part of an existing cluster. For example, you may wish to augment a Kubernetes cluster with groups of workers with a different machine type, larger disks, or preemptibility.
+Typhoon AWS and Google Cloud allow additional groups of workers to be defined and joined to a cluster. For example, add worker pools of instances with different types, disk sizes, Container Linux channels, or preemptibility modes.
+
+Internal Terraform Modules:
+
+* `aws/container-linux/kubernetes/workers`
+* `google-cloud/container-linux/kubernetes/workers`
+
+## AWS
+
+Create a cluster following the AWS [tutorial](../aws.md#cluster). Define a worker pool using the AWS internal `workers` module.
+
+```tf
+module "tempest-worker-pool" {
+  source = "git::https://github.com/poseidon/typhoon//aws/container-linux/kubernetes/workers?ref=v1.9.4"
+  
+  providers = {
+    aws = "aws.default"
+  }
+
+  # AWS
+  vpc_id          = "${module.aws-tempest.vpc_id}"
+  subnet_ids      = "${module.aws-tempest.subnet_ids}"
+  security_groups = "${module.aws-tempest.worker_security_groups}"
+  
+  # configuration
+  cluster_name       = "tempest-worker-pool"
+  kubeconfig         = "${module.aws-tempest.kubeconfig}"
+  ssh_authorized_key = "${var.ssh_authorized_key}"
+
+  count         = 2
+  instance_type = "m5.large"
+  os_channel    = "beta"    
+}
+```
+
+Apply the change.
+
+```
+terraform apply
+```
+
+Verify an auto-scaling group of workers join the cluster within a few minutes.
+
+### Variables
+
+The AWS internal `workers` module supports a number of [variables](https://github.com/poseidon/typhoon/blob/master/aws/container-linux/kubernetes/workers/variables.tf).
+
+#### Required
+
+| Name | Description | Example |
+|:-----|:------------|:--------|
+| vpc_id | Must be set to `vpc_id` output by cluster | "${module.cluster.vpc_id}" |
+| subnet_ids | Must be set to `subnet_ids` output by cluster | "${module.cluster.subnet_ids}" |
+| security_groups | Must be set to `worker_security_groups` output by cluster | "${module.cluster.worker_security_groups}" |
+| cluster_name | Unique name | "tempest-worker-pool" |
+| kubeconfig | Must be set to `kubeconfig` output by cluster | "${module.cluster.kubeconfig}" |
+| ssh_authorized_key | SSH public key for ~/.ssh_authorized_keys | "ssh-rsa AAAAB3NZ..." |
+
+#### Optional
+
+| Name | Description | Default | Example |
+|:-----|:------------|:--------|:--------|
+| count | Number of instances | 1 | 3 |
+| instance_type | EC2 instance type | "t2.small" | "t2.medium" |
+| os_channel | Container Linux AMI channel | stable| "beta", "alpha" |
+| disk_size | Size of the disk in GB | 40 | 100 |
+| service_cidr | Must match `service_cidr` of cluster | "10.3.0.0/16" | "10.3.0.0/24" |
+| cluster_domain_suffix | Must match `cluster_domain_suffix` of cluster | "cluster.local" | "k8s.example.com" |
+
+Check the list of valid [instance types](https://aws.amazon.com/ec2/instance-types/).
 
 ## Google Cloud
 
-Create a cluster following the Google Cloud [tutorial](../google-cloud.md#cluster). Then define a worker pool using the internal `workers` Terraform module.
+Create a cluster following the Google Cloud [tutorial](../google-cloud.md#cluster). Define a worker pool using the Google Cloud internal `workers` module.
 
 ```tf
 module "yavin-worker-pool" {
   source = "git::https://github.com/poseidon/typhoon//google-cloud/container-linux/kubernetes/workers?ref=v1.9.4"
 
   # Google Cloud
-  network      = "${module.google-cloud-yavin.network_name}"
   region  = "us-central1"
-  count        = 2
+  network = "${module.google-cloud-yavin.network_name}"
-  machine_type = "n1-standard-16"
-  preemptible  = true
 
+  # configuration
   cluster_name       = "yavin-16x"
+  kubeconfig         = "${module.google-cloud-yavin.kubeconfig}"
   ssh_authorized_key = "${var.ssh_authorized_key}"
   
-  kubeconfig = "${module.google-cloud-yavin.kubeconfig}"
+  count        = 2
+  machine_type = "n1-standard-16"
+  os_image     = "coreos-beta"
+  preemptible  = true
 }
 ```
 
@@ -50,22 +121,23 @@ The Google Cloud internal `workers` module supports a number of [variables](http
 
 | Name | Description | Example |
 |:-----|:------------|:--------|
+| region | Must be set to `region` of cluster | "us-central1" |
+| network | Must be set to `network_name` output by cluster | "${module.cluster.network_name}" |
 | cluster_name | Unique name | "yavin-worker-pool" |
-| region | Must match region of cluster | "us-central1" |
+| kubeconfig | Must be set to `kubeconfig` output by cluster | "${module.cluster.kubeconfig}" |
-| network | Must match network name output by cluster | "${module.cluster.network_name}" |
 | ssh_authorized_key | SSH public key for ~/.ssh_authorized_keys | "ssh-rsa AAAAB3NZ..." |
 
 #### Optional
 
 | Name | Description | Default | Example |
 |:-----|:------------|:--------|:--------|
-| count | Number of workers | 1 | 3 |
+| count | Number of instances | 1 | 3 |
-| machine_type | Machine type for compute instances | "n1-standard-1" | See below |
+| machine_type | Compute instance machine type | "n1-standard-1" | See below |
-| os_image | OS image for compute instances | "coreos-stable" | "coreos-alpha" |
+| os_image | OS image for compute instances | "coreos-stable" | "coreos-alpha", "coreos-beta" |
 | disk_size | Size of the disk in GB | 40 | 100 |
-| preemptible | If enabled, Compute Engine will terminate instances randomly within 24 hours | false | true |
+| preemptible | If true, Compute Engine will terminate instances randomly within 24 hours | false | true |
-| service_cidr | Must match service_cidr of cluster | "10.3.0.0/16" | "10.3.0.0/24" |
+| service_cidr | Must match `service_cidr` of cluster | "10.3.0.0/16" | "10.3.0.0/24" |
-| cluster_domain_suffix | Must match domain suffix of cluster | "cluster.local" | "k8s.example.com" |
+| cluster_domain_suffix | Must match `cluster_domain_suffix` of cluster | "cluster.local" | "k8s.example.com" |
 
 Check the list of valid [machine types](https://cloud.google.com/compute/docs/machine-types).
 

docs/index.md

@@ -14,6 +14,7 @@ Typhoon distributes upstream Kubernetes, architectural conventions, and cluster
 * Kubernetes v1.9.3 (upstream, via [kubernetes-incubator/bootkube](https://github.com/kubernetes-incubator/bootkube))
 * Single or multi-master, workloads isolated on workers, [Calico](https://www.projectcalico.org/) or [flannel](https://github.com/coreos/flannel) networking
 * On-cluster etcd with TLS, [RBAC](https://kubernetes.io/docs/admin/authorization/rbac/)-enabled, [network policy](https://kubernetes.io/docs/concepts/services-networking/network-policies/)
+* Advanced features like [worker pools](https://typhoon.psdn.io/advanced/worker-pools/) and [preemption](https://typhoon.psdn.io/google-cloud/#preemption) (varies by platform)
 * Ready for Ingress, Dashboards, Metrics and other optional [addons](addons/overview.md)
 * Provided via Terraform Modules