typhoon/docs/advanced/worker-pools.md

Worker Pools

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
• aws/fedora-atomic/kubernetes/workers
• google-cloud/container-linux/kubernetes/workers
• google-cloud/fedora-atomic/kubernetes/workers

AWS

Create a cluster following the AWS tutorial. Define a worker pool using the AWS internal workers module.

module "tempest-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//aws/container-linux/kubernetes/workers?ref=v1.10.2"
  
  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
  name               = "tempest-worker-pool"
  kubeconfig         = "${module.aws-tempest.kubeconfig}"
  ssh_authorized_key = "${var.ssh_authorized_key}"

  count         = 2
  instance_type = "m5.large"
  os_image      = "coreos-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.

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	"${module.cluster.worker_security_groups}"
name	Unique name (distinct from cluster name)	"tempest-m5s"
kubeconfig	Must be set to kubeconfig output by cluster	"${module.cluster.kubeconfig}"
ssh_authorized_key	SSH public key for user 'core'	"ssh-rsa AAAAB3NZ..."

Optional

Name	Description	Default	Example
count	Number of instances	1	3
instance_type	EC2 instance type	"t2.small"	"t2.medium"
os_image	AMI channel for a Container Linux derivative	coreos-stable	coreos-stable, coreos-beta, coreos-alpha, flatcar-stable, flatcar-beta, flatcar-alpha
disk_size	Size of the disk in GB	40	100
spot_price	Spot price in USD for workers. Leave as default empty string for regular on-demand instances	""	"0.10"
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 or per-region and per-type spot prices.

Google Cloud

Create a cluster following the Google Cloud tutorial. Define a worker pool using the Google Cloud internal workers module.

module "yavin-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//google-cloud/container-linux/kubernetes/workers?ref=v1.10.2"

  providers = {
    google = "google.default"
  }

  # Google Cloud
  region       = "us-central1"
  network      = "${module.google-cloud-yavin.network_name}"
  cluster_name = "yavin"

  # configuration
  name               = "yavin-16x"
  kubeconfig         = "${module.google-cloud-yavin.kubeconfig}"
  ssh_authorized_key = "${var.ssh_authorized_key}"
  
  count        = 2
  machine_type = "n1-standard-16"
  os_image     = "coreos-beta"
  preemptible  = true
}

Apply the change.

terraform apply

Verify a managed instance group of workers joins the cluster within a few minutes.

$ kubectl get nodes
NAME                                             STATUS   AGE    VERSION
yavin-controller-0.c.example-com.internal        Ready    6m     v1.10.2
yavin-worker-jrbf.c.example-com.internal         Ready    5m     v1.10.2
yavin-worker-mzdm.c.example-com.internal         Ready    5m     v1.10.2
yavin-16x-worker-jrbf.c.example-com.internal     Ready    3m     v1.10.2
yavin-16x-worker-mzdm.c.example-com.internal     Ready    3m     v1.10.2

Variables

The Google Cloud internal workers module supports a number of variables.

Required

Name	Description	Example
region	Must be set to region of cluster	"us-central1"
network	Must be set to network_name output by cluster	"${module.cluster.network_name}"
name	Unique name (distinct from cluster name)	"yavin-16x"
cluster_name	Must be set to cluster_name of cluster	"yavin"
kubeconfig	Must be set to kubeconfig output by cluster	"${module.cluster.kubeconfig}"
ssh_authorized_key	SSH public key for user 'core'	"ssh-rsa AAAAB3NZ..."

Optional

Name	Description	Default	Example
count	Number of instances	1	3
machine_type	Compute instance machine type	"n1-standard-1"	See below
os_image	Container Linux image for compute instances	"coreos-stable"	"coreos-alpha", "coreos-beta"
disk_size	Size of the disk in GB	40	100
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"
cluster_domain_suffix	Must match cluster_domain_suffix of cluster	"cluster.local"	"k8s.example.com"

Check the list of valid machine types.