typhoon/docs/advanced/worker-pools.md

12 KiB

Worker Pools

Typhoon AWS, Azure, 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/flatcar-linux/kubernetes/workers
  • aws/fedora-coreos/kubernetes/workers
  • azure/flatcar-linux/kubernetes/workers
  • azure/fedora-coreos/kubernetes/workers
  • google-cloud/flatcar-linux/kubernetes/workers
  • google-cloud/fedora-coreos/kubernetes/workers

AWS

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

=== "Fedora CoreOS"

```tf
module "tempest-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//aws/fedora-coreos/kubernetes/workers?ref=v1.20.3"

  # AWS
  vpc_id          = module.tempest.vpc_id
  subnet_ids      = module.tempest.subnet_ids
  security_groups = module.tempest.worker_security_groups

  # configuration
  name               = "tempest-pool"
  kubeconfig         = module.tempest.kubeconfig
  ssh_authorized_key = var.ssh_authorized_key

  # optional
  worker_count  = 2
  instance_type = "m5.large"
  os_stream     = "next"
}
```

=== "Flatcar Linux"

```tf
module "tempest-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//aws/flatcar-linux/kubernetes/workers?ref=v1.20.3"

  # AWS
  vpc_id          = module.tempest.vpc_id
  subnet_ids      = module.tempest.subnet_ids
  security_groups = module.tempest.worker_security_groups

  # configuration
  name               = "tempest-pool"
  kubeconfig         = module.tempest.kubeconfig
  ssh_authorized_key = var.ssh_authorized_key

  # optional
  worker_count  = 2
  instance_type = "m5.large"
  os_image      = "flatcar-beta"
}
```

Apply the change.

terraform apply

Verify an auto-scaling group of workers joins the cluster within a few minutes.

Variables

The AWS internal workers module supports a number of variables.

Required

Name Description Example
name Unique name (distinct from cluster name) "tempest-m5s"
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
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
worker_count Number of instances 1 3
instance_type EC2 instance type "t3.small" "t3.medium"
os_image AMI channel for a Container Linux derivative "flatcar-stable" flatcar-stable, flatcar-beta, flatcar-alpha, flatcar-edge
os_stream Fedora CoreOS stream for compute instances "stable" "testing", "next"
disk_size Size of the EBS volume in GB 40 100
disk_type Type of the EBS volume "gp2" standard, gp2, io1
disk_iops IOPS of the EBS volume 0 (i.e. auto) 400
spot_price Spot price in USD for worker instances or 0 to use on-demand instances 0 0.10
snippets Fedora CoreOS or Container Linux Config snippets [] examples
service_cidr Must match service_cidr of cluster "10.3.0.0/16" "10.3.0.0/24"
node_labels List of initial node labels [] ["worker-pool=foo"]

Check the list of valid instance types or per-region and per-type spot prices.

Azure

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

=== "Fedora CoreOS"

```tf
module "ramius-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//azure/fedora-coreos/kubernetes/workers?ref=v1.20.3"

  # Azure
  region                  = module.ramius.region
  resource_group_name     = module.ramius.resource_group_name
  subnet_id               = module.ramius.subnet_id
  security_group_id       = module.ramius.security_group_id
  backend_address_pool_id = module.ramius.backend_address_pool_id

  # configuration
  name               = "ramius-spot"
  kubeconfig         = module.ramius.kubeconfig
  ssh_authorized_key = var.ssh_authorized_key

  # optional
  worker_count = 2
  vm_type      = "Standard_F4"
  priority     = "Spot"
  os_image     = "/subscriptions/some/path/Microsoft.Compute/images/fedora-coreos-31.20200323.3.2"
}
```

=== "Flatcar Linux"

```tf
module "ramius-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//azure/flatcar-linux/kubernetes/workers?ref=v1.20.3"

  # Azure
  region                  = module.ramius.region
  resource_group_name     = module.ramius.resource_group_name
  subnet_id               = module.ramius.subnet_id
  security_group_id       = module.ramius.security_group_id
  backend_address_pool_id = module.ramius.backend_address_pool_id

  # configuration
  name               = "ramius-spot"
  kubeconfig         = module.ramius.kubeconfig
  ssh_authorized_key = var.ssh_authorized_key

  # optional
  worker_count = 2
  vm_type      = "Standard_F4"
  priority     = "Spot"
  os_image     = "flatcar-beta"
}
```

Apply the change.

terraform apply

Verify a scale set of workers joins the cluster within a few minutes.

Variables

The Azure internal workers module supports a number of variables.

Required

Name Description Example
name Unique name (distinct from cluster name) "ramius-f4"
region Must be set to region output by cluster module.cluster.region
resource_group_name Must be set to resource_group_name output by cluster module.cluster.resource_group_name
subnet_id Must be set to subnet_id output by cluster module.cluster.subnet_id
security_group_id Must be set to security_group_id output by cluster module.cluster.security_group_id
backend_address_pool_id Must be set to backend_address_pool_id output by cluster module.cluster.backend_address_pool_id
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
worker_count Number of instances 1 3
vm_type Machine type for instances "Standard_DS1_v2" See below
os_image Channel for a Container Linux derivative "flatcar-stable" flatcar-stable, flatcar-beta, flatcar-alpha, flatcar-edge
priority Set priority to Spot to use reduced cost surplus capacity, with the tradeoff that instances can be deallocated at any time "Regular" "Spot"
snippets Container Linux Config snippets [] examples
service_cidr CIDR IPv4 range to assign to Kubernetes services "10.3.0.0/16" "10.3.0.0/24"
node_labels List of initial node labels [] ["worker-pool=foo"]

Check the list of valid machine types and their specs. Use az vm list-skus to get the identifier.

Google Cloud

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

=== "Fedora CoreOS"

```tf
module "yavin-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//google-cloud/fedora-coreos/kubernetes/workers?ref=v1.20.3"

  # Google Cloud
  region       = "europe-west2"
  network      = module.yavin.network_name
  cluster_name = "yavin"

  # configuration
  name               = "yavin-16x"
  kubeconfig         = module.yavin.kubeconfig
  ssh_authorized_key = var.ssh_authorized_key

  # optional
  worker_count = 2
  machine_type = "n1-standard-16"
  os_stream    = "testing"
  preemptible  = true
}
```

=== "Flatcar Linux"

```tf
module "yavin-worker-pool" {
  source = "git::https://github.com/poseidon/typhoon//google-cloud/flatcar-linux/kubernetes/workers?ref=v1.20.3"

  # Google Cloud
  region       = "europe-west2"
  network      = module.yavin.network_name
  cluster_name = "yavin"

  # configuration
  name               = "yavin-16x"
  kubeconfig         = module.yavin.kubeconfig
  ssh_authorized_key = var.ssh_authorized_key

  # optional
  worker_count = 2
  machine_type = "n1-standard-16"
  os_image     = "flatcar-linux-2303-4-0"    # custom
  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     v1.20.3
yavin-worker-jrbf.c.example-com.internal         Ready    5m     v1.20.3
yavin-worker-mzdm.c.example-com.internal         Ready    5m     v1.20.3
yavin-16x-worker-jrbf.c.example-com.internal     Ready    3m     v1.20.3
yavin-16x-worker-mzdm.c.example-com.internal     Ready    3m     v1.20.3

Variables

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

Required

Name Description Example
name Unique name (distinct from cluster name) "yavin-16x"
cluster_name Must be set to cluster_name of cluster "yavin"
region Region for the worker pool instances. May differ from the cluster's region "europe-west2"
network Must be set to network_name output by cluster module.cluster.network_name
kubeconfig Must be set to kubeconfig output by cluster module.cluster.kubeconfig
os_image Container Linux image for compute instances "uploaded-flatcar-image"
ssh_authorized_key SSH public key for user 'core' "ssh-rsa AAAAB3NZ..."

Check the list of regions docs or with gcloud compute regions list.

Optional

Name Description Default Example
worker_count Number of instances 1 3
machine_type Compute instance machine type "n1-standard-1" See below
os_stream Fedora CoreOS stream for compute instances "stable" "testing", "next"
disk_size Size of the disk in GB 40 100
preemptible If true, Compute Engine will terminate instances randomly within 24 hours false true
snippets Container Linux Config snippets [] examples
service_cidr Must match service_cidr of cluster "10.3.0.0/16" "10.3.0.0/24"
node_labels List of initial node labels [] ["worker-pool=foo"]

Check the list of valid machine types.