typhoon/docs/cl/google-cloud.md

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# Google Cloud
In this tutorial, we'll create a Kubernetes v1.17.3 cluster on Google Compute Engine with CoreOS Container Linux or Flatcar Linux.
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.
Controller hosts are provisioned to run an `etcd-member` peer and a `kubelet` service. Worker hosts run a `kubelet` service. Controller nodes run `kube-apiserver`, `kube-scheduler`, `kube-controller-manager`, and `coredns`, while `kube-proxy` and `calico` (or `flannel`) run on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
## Requirements
* Google Cloud Account and Service Account
* Google Cloud DNS Zone (registered Domain Name or delegated subdomain)
* Terraform v0.12.6+ and [terraform-provider-ct](https://github.com/poseidon/terraform-provider-ct) installed locally
## Terraform Setup
Install [Terraform](https://www.terraform.io/downloads.html) v0.12.6+ on your system.
```sh
$ terraform version
Terraform v0.12.20
```
Add the [terraform-provider-ct](https://github.com/poseidon/terraform-provider-ct) plugin binary for your system to `~/.terraform.d/plugins/`, noting the final name.
```sh
wget https://github.com/poseidon/terraform-provider-ct/releases/download/v0.4.0/terraform-provider-ct-v0.4.0-linux-amd64.tar.gz
tar xzf terraform-provider-ct-v0.4.0-linux-amd64.tar.gz
mv terraform-provider-ct-v0.4.0-linux-amd64/terraform-provider-ct ~/.terraform.d/plugins/terraform-provider-ct_v0.4.0
```
Read [concepts](/architecture/concepts/) to learn about Terraform, modules, and organizing resources. Change to your infrastructure repository (e.g. `infra`).
```
cd infra/clusters
```
## Provider
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.
Select "Credentials" and create a service account key. Choose the "Compute Engine Admin" and "DNS Administrator" roles and save the JSON private key to a file that can be referenced in configs.
```sh
mv ~/Downloads/project-id-43048204.json ~/.config/google-cloud/terraform.json
```
Configure the Google Cloud provider to use your service account key, project-id, and region in a `providers.tf` file.
```tf
provider "google" {
version = "3.7.0"
project = "project-id"
region = "us-central1"
credentials = file("~/.config/google-cloud/terraform.json")
}
provider "ct" {
version = "0.4.0"
}
```
Additional configuration options are described in the `google` provider [docs](https://www.terraform.io/docs/providers/google/index.html).
!!! tip
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.
## Cluster
Define a Kubernetes cluster using the module `google-cloud/container-linux/kubernetes`.
```tf
module "yavin" {
source = "git::https://github.com/poseidon/typhoon//google-cloud/container-linux/kubernetes?ref=v1.17.3"
# Google Cloud
cluster_name = "yavin"
region = "us-central1"
dns_zone = "example.com"
dns_zone_name = "example-zone"
# configuration
ssh_authorized_key = "ssh-rsa AAAAB3Nz..."
# optional
worker_count = 2
}
```
Reference the [variables docs](#variables) or the [variables.tf](https://github.com/poseidon/typhoon/blob/master/google-cloud/container-linux/kubernetes/variables.tf) source.
### Flatcar Linux Images
!!! success
Skip this section when using CoreOS Container Linux (default). CoreOS Container Linux publishes official images to Google Cloud.
!!! danger
Typhoon for Flatcar Linux on Google Cloud is alpha.
Flatcar Linux publishes images for Google Cloud, but does not yet upload them. Google Cloud allows [custom boot images](https://cloud.google.com/compute/docs/images/import-existing-image) to be uploaded to a bucket and imported into your project.
[Download](https://www.flatcar-linux.org/releases/) the Flatcar Linux GCE gzipped tarball and upload it to a Google Cloud storage bucket.
```
gsutil list
gsutil cp flatcar_production_gce.tar.gz gs://BUCKET
```
Create a Compute Engine image from the file.
```
gcloud compute images create flatcar-linux-2303-4-0 --source-uri gs://BUCKET_NAME/flatcar_production_gce.tar.gz
```
Set the [os_image](#variables) to the image name (e.g. `flatcar-linux-2303-4-0`)
## ssh-agent
Initial bootstrapping requires `bootstrap.service` be started on one controller node. Terraform uses `ssh-agent` to automate this step. Add your SSH private key to `ssh-agent`.
```sh
ssh-add ~/.ssh/id_rsa
ssh-add -L
```
## Apply
Initialize the config directory if this is the first use with Terraform.
```sh
terraform init
```
Plan the resources to be created.
```sh
$ terraform plan
Plan: 64 to add, 0 to change, 0 to destroy.
```
Apply the changes to create the cluster.
```sh
$ terraform apply
module.yavin.null_resource.bootstrap: Still creating... (10s elapsed)
...
module.yavin.null_resource.bootstrap: Still creating... (5m30s elapsed)
module.yavin.null_resource.bootstrap: Still creating... (5m40s elapsed)
module.yavin.null_resource.bootstrap: Creation complete (ID: 5768638456220583358)
Apply complete! Resources: 62 added, 0 changed, 0 destroyed.
```
In 4-8 minutes, the Kubernetes cluster will be ready.
## Verify
[Install kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) on your system. Obtain the generated cluster `kubeconfig` from module outputs (e.g. write to a local file).
```
resource "local_file" "kubeconfig-yavin" {
content = module.yavin.kubeconfig-admin
filename = "/home/user/.kube/configs/yavin-config"
}
```
List nodes in the cluster.
```
$ export KUBECONFIG=/home/user/.kube/configs/yavin-config
$ kubectl get nodes
NAME ROLES STATUS AGE VERSION
yavin-controller-0.c.example-com.internal <none> Ready 6m v1.17.3
yavin-worker-jrbf.c.example-com.internal <none> Ready 5m v1.17.3
yavin-worker-mzdm.c.example-com.internal <none> Ready 5m v1.17.3
```
List the pods.
```
$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-node-1cs8z 2/2 Running 0 6m
kube-system calico-node-d1l5b 2/2 Running 0 6m
kube-system calico-node-sp9ps 2/2 Running 0 6m
kube-system coredns-1187388186-dkh3o 1/1 Running 0 6m
kube-system coredns-1187388186-zj5dl 1/1 Running 0 6m
kube-system kube-apiserver-controller-0 1/1 Running 0 6m
kube-system kube-controller-manager-controller-0 1/1 Running 0 6m
kube-system kube-proxy-117v6 1/1 Running 0 6m
kube-system kube-proxy-9886n 1/1 Running 0 6m
kube-system kube-proxy-njn47 1/1 Running 0 6m
kube-system kube-scheduler-controller-0 1/1 Running 0 6m
```
## Going Further
Learn about [maintenance](/topics/maintenance/) and [addons](/addons/overview/).
!!! note
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.
## Variables
Check the [variables.tf](https://github.com/poseidon/typhoon/blob/master/google-cloud/container-linux/kubernetes/variables.tf) source.
### Required
| Name | Description | Example |
|:-----|:------------|:--------|
| cluster_name | Unique cluster name (prepended to dns_zone) | "yavin" |
| region | Google Cloud region | "us-central1" |
| dns_zone | Google Cloud DNS zone | "google-cloud.example.com" |
| dns_zone_name | Google Cloud DNS zone name | "example-zone" |
| ssh_authorized_key | SSH public key for user 'core' | "ssh-rsa AAAAB3NZ..." |
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`.
#### DNS Zone
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`.
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.
```tf
resource "google_dns_managed_zone" "zone-for-clusters" {
dns_name = "google-cloud.example.com."
name = "example-zone"
description = "Production DNS zone"
}
```
!!! tip ""
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).
### Optional
| Name | Description | Default | Example |
|:-----|:------------|:--------|:--------|
| asset_dir | Absolute path to a directory where generated assets should be placed (contains secrets) | "" (disabled) | "/home/user/.secrets/clusters/yavin" |
| controller_count | Number of controllers (i.e. masters) | 1 | 3 |
| worker_count | Number of workers | 1 | 3 |
| controller_type | Machine type for controllers | "n1-standard-1" | See below |
| worker_type | Machine type for workers | "n1-standard-1" | See below |
| os_image | Container Linux image for compute instances | "coreos-stable" | "flatcar-linux-2303-4-0" |
| disk_size | Size of the disk in GB | 40 | 100 |
| worker_preemptible | If enabled, Compute Engine will terminate workers randomly within 24 hours | false | true |
| controller_clc_snippets | Controller Container Linux Config snippets | [] | [example](/advanced/customization/) |
| worker_clc_snippets | Worker Container Linux Config snippets | [] | [example](/advanced/customization/) |
| networking | Choice of networking provider | "calico" | "calico" or "flannel" |
| pod_cidr | CIDR IPv4 range to assign to Kubernetes pods | "10.2.0.0/16" | "10.22.0.0/16" |
| service_cidr | CIDR IPv4 range to assign to Kubernetes services | "10.3.0.0/16" | "10.3.0.0/24" |
| worker_node_labels | List of initial worker node labels | [] | ["worker-pool=default"] |
Check the list of valid [machine types](https://cloud.google.com/compute/docs/machine-types).
#### Preemption
Add `worker_preemptible = "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.`