typhoon/docs/advanced/worker-pools.md

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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
  • google-cloud/container-linux/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=v1.9.4"
  
  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.

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.

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=v1.9.4"

  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     v1.9.3
yavin-worker-jrbf.c.example-com.internal         Ready    5m     v1.9.3
yavin-worker-mzdm.c.example-com.internal         Ready    5m     v1.9.3
yavin-16x-worker-jrbf.c.example-com.internal     Ready    3m     v1.9.3
yavin-16x-worker-mzdm.c.example-com.internal     Ready    3m     v1.9.3

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 ~/.ssh_authorized_keys "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 OS 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.