242 lines
10 KiB
Markdown
242 lines
10 KiB
Markdown
# Google Cloud
|
|
|
|
In this tutorial, we'll create a Kubernetes v1.7.3 cluster on Google Compute Engine (not GKE).
|
|
|
|
We'll declare a Kubernetes cluster in Terraform using the Typhoon Terraform module. On apply, a network, firewall rules, managed instance groups of Kubernetes controllers and workers, network load balancers for controllers and workers, and health checks will be created.
|
|
|
|
Controllers and workers are provisioned to run a `kubelet`. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules `etcd`, `apiserver`, `scheduler`, `controller-manager`, and `kube-dns` on controllers and runs `kube-proxy` and `flannel` on each 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 v0.9.2+ and [terraform-provider-ct](https://github.com/coreos/terraform-provider-ct) installed locally
|
|
|
|
## Terraform Setup
|
|
|
|
Install [Terraform](https://www.terraform.io/downloads.html) v0.9.2+ on your system.
|
|
|
|
```sh
|
|
$ terraform version
|
|
Terraform v0.10.1
|
|
```
|
|
|
|
Add the [terraform-provider-ct](https://github.com/coreos/terraform-provider-ct) plugin binary for your system.
|
|
|
|
```sh
|
|
wget https://github.com/coreos/terraform-provider-ct/releases/download/v0.2.0/terraform-provider-ct-v0.2.0-linux-amd64.tar.gz
|
|
tar xzf terraform-provider-ct-v0.2.0-linux-amd64.tar.gz
|
|
sudo mv terraform-provider-ct-v0.2.0-linux-amd64/terraform-provider-ct /usr/local/bin/
|
|
```
|
|
|
|
Add the plugin to your `~/.terraformrc`.
|
|
|
|
```
|
|
providers {
|
|
ct = "/usr/local/bin/terraform-provider-ct"
|
|
}
|
|
```
|
|
|
|
Read [concepts](concepts.md) 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 service account key credentials. Choose the "Compute Engine default service account" 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" {
|
|
credentials = "${file("~/.config/google-cloud/terraform.json")}"
|
|
project = "project-id"
|
|
region = "us-central1"
|
|
}
|
|
```
|
|
|
|
Additional configuration options are described in the `google` provider [docs](https://www.terraform.io/docs/providers/google/index.html).
|
|
|
|
!!! tip
|
|
A project may contain multiple clusters if you wish. Regions are listed in [docs](https://cloud.google.com/compute/docs/regions-zones/regions-zones) or with `gcloud compute regions list`.
|
|
|
|
## Cluster
|
|
|
|
Define a Kubernetes cluster using the module `google-cloud/container-linux/kubernetes`.
|
|
|
|
```tf
|
|
module "google-cloud-yavin" {
|
|
source = "git::https://github.com/poseidon/typhoon//google-cloud/container-linux/kubernetes"
|
|
|
|
# Google Cloud
|
|
zone = "us-central1-c"
|
|
dns_zone = "example.com"
|
|
dns_zone_name = "example-zone"
|
|
os_image = "coreos-stable-1465-6-0-v20170817"
|
|
|
|
cluster_name = "yavin"
|
|
controller_count = 1
|
|
worker_count = 2
|
|
ssh_authorized_key = "ssh-rsa AAAAB3Nz..."
|
|
|
|
# output assets dir
|
|
asset_dir = "/home/user/.secrets/clusters/yavin"
|
|
}
|
|
```
|
|
|
|
Reference the [variables docs](#variables) or the [variables.tf](https://github.com/poseidon/typhoon/blob/master/google-cloud/container-linux/kubernetes/variables.tf) source.
|
|
|
|
## ssh-agent
|
|
|
|
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`.
|
|
|
|
```sh
|
|
ssh-add ~/.ssh/id_rsa
|
|
ssh-add -L
|
|
```
|
|
|
|
!!! warning
|
|
`terrafrom apply` will hang connecting to a controller if `ssh-agent` does not contain the SSH key.
|
|
|
|
## Apply
|
|
|
|
Initialize the config directory if this is the first use with Terraform.
|
|
|
|
```sh
|
|
terraform init
|
|
```
|
|
|
|
Get or update Terraform modules.
|
|
|
|
```sh
|
|
$ terraform get # downloads missing modules
|
|
$ terraform get --update # updates all modules
|
|
Get: git::https://github.com/poseidon/typhoon (update)
|
|
Get: git::https://github.com/poseidon/bootkube-terraform.git?ref=v0.6.1 (update)
|
|
```
|
|
|
|
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.google-cloud-yavin.null_resource.bootkube-start: Still creating... (10s elapsed)
|
|
...
|
|
|
|
module.google-cloud-yavin.null_resource.bootkube-start: Still creating... (8m30s elapsed)
|
|
module.google-cloud-yavin.null_resource.bootkube-start: Still creating... (8m40s elapsed)
|
|
module.google-cloud-yavin.null_resource.bootkube-start: Creation complete (ID: 5768638456220583358)
|
|
|
|
Apply complete! Resources: 64 added, 0 changed, 0 destroyed.
|
|
```
|
|
|
|
In 5-10 minutes, the Kubernetes cluster will be ready.
|
|
|
|
## Verify
|
|
|
|
[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.
|
|
|
|
```
|
|
$ KUBECONFIG=/home/user/.secrets/clusters/yavin/auth/kubeconfig
|
|
$ kubectl get nodes
|
|
NAME STATUS AGE VERSION
|
|
yavin-controller-1682.c.example-com.internal Ready 6m v1.7.3+coreos.0
|
|
yavin-worker-jrbf.c.example-com.internal Ready 5m v1.7.3+coreos.0
|
|
yavin-worker-mzdm.c.example-com.internal Ready 5m v1.7.3+coreos.0
|
|
```
|
|
|
|
List the pods.
|
|
|
|
```
|
|
$ kubectl get pods --all-namespaces
|
|
NAMESPACE NAME READY STATUS RESTARTS AGE
|
|
kube-system etcd-operator-3329263108-f443m 1/1 Running 1 6m
|
|
kube-system kube-apiserver-zppls 1/1 Running 0 6m
|
|
kube-system kube-controller-manager-3271970485-gh9kt 1/1 Running 0 6m
|
|
kube-system kube-controller-manager-3271970485-h90v8 1/1 Running 1 6m
|
|
kube-system kube-dns-1187388186-zj5dl 3/3 Running 0 6m
|
|
kube-system kube-etcd-0000 1/1 Running 0 5m
|
|
kube-system kube-etcd-network-checkpointer-crznb 1/1 Running 0 6m
|
|
kube-system kube-flannel-1cs8z 2/2 Running 0 6m
|
|
kube-system kube-flannel-d1l5b 2/2 Running 0 6m
|
|
kube-system kube-flannel-sp9ps 2/2 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-3895335239-5x87r 1/1 Running 0 6m
|
|
kube-system kube-scheduler-3895335239-bzrrt 1/1 Running 1 6m
|
|
kube-system pod-checkpointer-l6lrt 1/1 Running 0 6m
|
|
```
|
|
|
|
## Going Further
|
|
|
|
Learn about [version pinning](concepts.md#versioning), maintenance, and [addons](addons/overview.md).
|
|
|
|
!!! note
|
|
On Container Linux clusters, install the `container-linux-update-operator` addon to coordinate reboots and drains when nodes auto-update. Otherwise, updates may not be applied until the next reboot.
|
|
|
|
## Variables
|
|
|
|
### Required
|
|
|
|
| Name | Description | Example |
|
|
|:-----|:------------|:--------|
|
|
| cluster_name | Unique cluster name (prepended to dns_zone) | "yavin" |
|
|
| zone | Google Cloud zone | "us-central1-f" |
|
|
| 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 ~/.ssh_authorized_keys | "ssh-rsa AAAAB3NZ..." |
|
|
| os_image | OS image for compute instances | "coreos-stable-1465-6-0-v20170817" |
|
|
| asset_dir | Path to a directory where generated assets should be placed (contains secrets) | "/home/user/.secrets/clusters/yavin" |
|
|
|
|
Check the list of valid [zones](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 network load balancer backed by controller instances. This FQDN is used by workers and `kubectl` to access the apiserver. In this example, the cluster's apiserver would be accessible at `yavin.google-cloud.example.com`.
|
|
|
|
You'll need a registered domain name or subdomain registered in a Google Cloud DNS zone. You can set this up once and create many clusters with unqiue 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 carve out 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 |
|
|
|:-----|:------------|:--------|:--------|
|
|
| machine_type | Machine type for compute instances | "n1-standard-1" | See below |
|
|
| controller_count | Number of controllers (i.e. masters) | 1 | 1 |
|
|
| worker_count | Number of workers | 1 | 3 |
|
|
| worker_preemptible | If enabled, Compute Engine will terminate controllers randomly within 24 hours | false | true |
|
|
| pod_cidr | CIDR range to assign to Kubernetes pods | "10.2.0.0/16" | "10.22.0.0/16" |
|
|
| service_cidr | CIDR range to assgin to Kubernetes services | "10.3.0.0/16" | "10.3.0.0/24" |
|
|
|
|
Check the list of valid [machine types](https://cloud.google.com/compute/docs/machine-types).
|
|
|
|
#### Preemption
|
|
|
|
Add `worker_premeptible = "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.`
|
|
|