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* Prefer InternalIP and ExternalIP over the node's hostname, to match upstream behavior and kubeadm * Previously, hostname-override was used to set node names to internal IP's to work around some cloud providers not resolving hostnames for instances (e.g. DO droplets)
266 lines
11 KiB
Markdown
266 lines
11 KiB
Markdown
# Google Cloud
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In this tutorial, we'll create a Kubernetes v1.12.2 cluster on Google Compute Engine with Container Linux.
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We'll declare a Kubernetes cluster using the Typhoon Terraform module. Then apply the changes to create a network, firewall rules, health checks, controller instances, worker managed instance group, load balancers, and TLS assets.
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Controllers are provisioned to run an `etcd-member` peer and a `kubelet` service. Workers run just a `kubelet` service. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules the `apiserver`, `scheduler`, `controller-manager`, and `coredns` on controllers and schedules `kube-proxy` and `calico` (or `flannel`) on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
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## Requirements
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* Google Cloud Account and Service Account
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* Google Cloud DNS Zone (registered Domain Name or delegated subdomain)
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* Terraform v0.11.x and [terraform-provider-ct](https://github.com/coreos/terraform-provider-ct) installed locally
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## Terraform Setup
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Install [Terraform](https://www.terraform.io/downloads.html) v0.11.x on your system.
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```sh
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$ terraform version
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Terraform v0.11.7
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```
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Add the [terraform-provider-ct](https://github.com/coreos/terraform-provider-ct) plugin binary for your system.
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```sh
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wget https://github.com/coreos/terraform-provider-ct/releases/download/v0.2.1/terraform-provider-ct-v0.2.1-linux-amd64.tar.gz
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tar xzf terraform-provider-ct-v0.2.1-linux-amd64.tar.gz
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sudo mv terraform-provider-ct-v0.2.1-linux-amd64/terraform-provider-ct /usr/local/bin/
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```
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Add the plugin to your `~/.terraformrc`.
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```
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providers {
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ct = "/usr/local/bin/terraform-provider-ct"
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}
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```
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Read [concepts](/architecture/concepts/) to learn about Terraform, modules, and organizing resources. Change to your infrastructure repository (e.g. `infra`).
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```
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cd infra/clusters
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```
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## Provider
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Login to your Google Console [API Manager](https://console.cloud.google.com/apis/dashboard) and select a project, or [signup](https://cloud.google.com/free/) if you don't have an account.
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Select "Credentials" and create a service account key. Choose the "Compute Engine Admin" role and save the JSON private key to a file that can be referenced in configs.
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```sh
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mv ~/Downloads/project-id-43048204.json ~/.config/google-cloud/terraform.json
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```
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Configure the Google Cloud provider to use your service account key, project-id, and region in a `providers.tf` file.
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```tf
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provider "google" {
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version = "1.6"
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alias = "default"
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credentials = "${file("~/.config/google-cloud/terraform.json")}"
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project = "project-id"
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region = "us-central1"
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}
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provider "local" {
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version = "~> 1.0"
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alias = "default"
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}
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provider "null" {
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version = "~> 1.0"
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alias = "default"
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}
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provider "template" {
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version = "~> 1.0"
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alias = "default"
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}
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provider "tls" {
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version = "~> 1.0"
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alias = "default"
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}
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```
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Additional configuration options are described in the `google` provider [docs](https://www.terraform.io/docs/providers/google/index.html).
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!!! tip
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Regions are listed in [docs](https://cloud.google.com/compute/docs/regions-zones/regions-zones) or with `gcloud compute regions list`. A project may contain multiple clusters across different regions.
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## Cluster
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Define a Kubernetes cluster using the module `google-cloud/container-linux/kubernetes`.
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```tf
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module "google-cloud-yavin" {
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source = "git::https://github.com/poseidon/typhoon//google-cloud/container-linux/kubernetes?ref=v1.12.2"
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providers = {
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google = "google.default"
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local = "local.default"
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null = "null.default"
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template = "template.default"
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tls = "tls.default"
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}
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# Google Cloud
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cluster_name = "yavin"
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region = "us-central1"
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dns_zone = "example.com"
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dns_zone_name = "example-zone"
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# configuration
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ssh_authorized_key = "ssh-rsa AAAAB3Nz..."
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asset_dir = "/home/user/.secrets/clusters/yavin"
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# optional
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worker_count = 2
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}
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```
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Reference the [variables docs](#variables) or the [variables.tf](https://github.com/poseidon/typhoon/blob/master/google-cloud/container-linux/kubernetes/variables.tf) source.
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## ssh-agent
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Initial bootstrapping requires `bootkube.service` be started on one controller node. Terraform uses `ssh-agent` to automate this step. Add your SSH private key to `ssh-agent`.
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```sh
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ssh-add ~/.ssh/id_rsa
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ssh-add -L
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```
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## Apply
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Initialize the config directory if this is the first use with Terraform.
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```sh
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terraform init
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```
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Plan the resources to be created.
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```sh
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$ terraform plan
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Plan: 64 to add, 0 to change, 0 to destroy.
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```
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Apply the changes to create the cluster.
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```sh
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$ terraform apply
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module.google-cloud-yavin.null_resource.bootkube-start: Still creating... (10s elapsed)
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...
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module.google-cloud-yavin.null_resource.bootkube-start: Still creating... (5m30s elapsed)
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module.google-cloud-yavin.null_resource.bootkube-start: Still creating... (5m40s elapsed)
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module.google-cloud-yavin.null_resource.bootkube-start: Creation complete (ID: 5768638456220583358)
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Apply complete! Resources: 64 added, 0 changed, 0 destroyed.
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```
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In 4-8 minutes, the Kubernetes cluster will be ready.
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## Verify
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[Install kubectl](https://coreos.com/kubernetes/docs/latest/configure-kubectl.html) on your system. Use the generated `kubeconfig` credentials to access the Kubernetes cluster and list nodes.
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```
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$ export KUBECONFIG=/home/user/.secrets/clusters/yavin/auth/kubeconfig
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$ kubectl get nodes
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NAME ROLES STATUS AGE VERSION
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yavin-controller-0.c.example-com.internal controller,master Ready 6m v1.12.2
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yavin-worker-jrbf.c.example-com.internal node Ready 5m v1.12.2
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yavin-worker-mzdm.c.example-com.internal node Ready 5m v1.12.2
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```
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List the pods.
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```
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$ kubectl get pods --all-namespaces
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NAMESPACE NAME READY STATUS RESTARTS AGE
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kube-system calico-node-1cs8z 2/2 Running 0 6m
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kube-system calico-node-d1l5b 2/2 Running 0 6m
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kube-system calico-node-sp9ps 2/2 Running 0 6m
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kube-system coredns-1187388186-dkh3o 1/1 Running 0 6m
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kube-system coredns-1187388186-zj5dl 1/1 Running 0 6m
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kube-system kube-apiserver-zppls 1/1 Running 0 6m
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kube-system kube-controller-manager-3271970485-gh9kt 1/1 Running 0 6m
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kube-system kube-controller-manager-3271970485-h90v8 1/1 Running 1 6m
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kube-system kube-proxy-117v6 1/1 Running 0 6m
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kube-system kube-proxy-9886n 1/1 Running 0 6m
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kube-system kube-proxy-njn47 1/1 Running 0 6m
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kube-system kube-scheduler-3895335239-5x87r 1/1 Running 0 6m
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kube-system kube-scheduler-3895335239-bzrrt 1/1 Running 1 6m
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kube-system pod-checkpointer-l6lrt 1/1 Running 0 6m
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```
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## Going Further
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Learn about [maintenance](/topics/maintenance/) and [addons](/addons/overview/).
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!!! note
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On Container Linux clusters, install the `CLUO` addon to coordinate reboots and drains when nodes auto-update. Otherwise, updates may not be applied until the next reboot.
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## Variables
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Check the [variables.tf](https://github.com/poseidon/typhoon/blob/master/google-cloud/container-linux/kubernetes/variables.tf) source.
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### Required
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| Name | Description | Example |
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|:-----|:------------|:--------|
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| cluster_name | Unique cluster name (prepended to dns_zone) | "yavin" |
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| region | Google Cloud region | "us-central1" |
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| dns_zone | Google Cloud DNS zone | "google-cloud.example.com" |
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| dns_zone_name | Google Cloud DNS zone name | "example-zone" |
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| ssh_authorized_key | SSH public key for user 'core' | "ssh-rsa AAAAB3NZ..." |
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| asset_dir | Path to a directory where generated assets should be placed (contains secrets) | "/home/user/.secrets/clusters/yavin" |
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Check the list of valid [regions](https://cloud.google.com/compute/docs/regions-zones/regions-zones) and list Container Linux [images](https://cloud.google.com/compute/docs/images) with `gcloud compute images list | grep coreos`.
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#### DNS Zone
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Clusters create a DNS A record `${cluster_name}.${dns_zone}` to resolve a TCP proxy load balancer backed by controller instances. This FQDN is used by workers and `kubectl` to access the apiserver(s). In this example, the cluster's apiserver would be accessible at `yavin.google-cloud.example.com`.
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You'll need a registered domain name or delegated subdomain on Google Cloud DNS. You can set this up once and create many clusters with unique names.
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```tf
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resource "google_dns_managed_zone" "zone-for-clusters" {
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dns_name = "google-cloud.example.com."
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name = "example-zone"
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description = "Production DNS zone"
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}
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```
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!!! tip ""
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If you have an existing domain name with a zone file elsewhere, just delegate a subdomain that can be managed on Google Cloud (e.g. google-cloud.mydomain.com) and [update nameservers](https://cloud.google.com/dns/update-name-servers).
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### Optional
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| Name | Description | Default | Example |
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| controller_count | Number of controllers (i.e. masters) | 1 | 3 |
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| worker_count | Number of workers | 1 | 3 |
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| controller_type | Machine type for controllers | "n1-standard-1" | See below |
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| worker_type | Machine type for workers | "n1-standard-1" | See below |
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| os_image | Container Linux image for compute instances | "coreos-stable" | "coreos-stable-1632-3-0-v20180215" |
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| disk_size | Size of the disk in GB | 40 | 100 |
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| worker_preemptible | If enabled, Compute Engine will terminate workers randomly within 24 hours | false | true |
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| controller_clc_snippets | Controller Container Linux Config snippets | [] | [example](/advanced/customization/) |
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| worker_clc_snippets | Worker Container Linux Config snippets | [] | [example](/advanced/customization/) |
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| networking | Choice of networking provider | "calico" | "calico" or "flannel" |
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| pod_cidr | CIDR IPv4 range to assign to Kubernetes pods | "10.2.0.0/16" | "10.22.0.0/16" |
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| service_cidr | CIDR IPv4 range to assign to Kubernetes services | "10.3.0.0/16" | "10.3.0.0/24" |
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| cluster_domain_suffix | FQDN suffix for Kubernetes services answered by coredns. | "cluster.local" | "k8s.example.com" |
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Check the list of valid [machine types](https://cloud.google.com/compute/docs/machine-types).
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#### Preemption
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Add `worker_preemeptible = "true"` to allow worker nodes to be [preempted](https://cloud.google.com/compute/docs/instances/preemptible) at random, but pay [significantly](https://cloud.google.com/compute/pricing) less. Clusters tolerate stopping instances fairly well (reschedules pods, but cannot drain) and preemption provides a nice reward for running fault-tolerant cluster systems.`
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