235 lines
10 KiB
Markdown
235 lines
10 KiB
Markdown
# Digital Ocean
|
|
|
|
In this tutorial, we'll create a Kubernetes v1.15.2 cluster on DigitalOcean with Container Linux.
|
|
|
|
We'll declare a Kubernetes cluster using the Typhoon Terraform module. Then apply the changes to create controller droplets, worker droplets, DNS records, tags, and TLS assets.
|
|
|
|
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 `flannel` on every node. A generated `kubeconfig` provides `kubectl` access to the cluster.
|
|
|
|
## Requirements
|
|
|
|
* Digital Ocean Account and Token
|
|
* Digital Ocean Domain (registered Domain Name or delegated subdomain)
|
|
* Terraform v0.12.x 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.x on your system.
|
|
|
|
```sh
|
|
$ terraform version
|
|
Terraform v0.12.2
|
|
```
|
|
|
|
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/v0.3.2/terraform-provider-ct-v0.3.2-linux-amd64.tar.gz
|
|
tar xzf terraform-provider-ct-v0.3.2-linux-amd64.tar.gz
|
|
mv terraform-provider-ct-v0.3.2-linux-amd64/terraform-provider-ct ~/.terraform.d/plugins/terraform-provider-ct_v0.3.2
|
|
```
|
|
|
|
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 [DigitalOcean](https://cloud.digitalocean.com) or create an [account](https://cloud.digitalocean.com/registrations/new), if you don't have one.
|
|
|
|
Generate a Personal Access Token with read/write scope from the [API tab](https://cloud.digitalocean.com/settings/api/tokens). Write the token to a file that can be referenced in configs.
|
|
|
|
```sh
|
|
mkdir -p ~/.config/digital-ocean
|
|
echo "TOKEN" > ~/.config/digital-ocean/token
|
|
```
|
|
|
|
Configure the DigitalOcean provider to use your token in a `providers.tf` file.
|
|
|
|
```tf
|
|
provider "digitalocean" {
|
|
version = "1.4.0"
|
|
token = "${chomp(file("~/.config/digital-ocean/token"))}"
|
|
}
|
|
|
|
provider "ct" {
|
|
version = "0.3.2"
|
|
}
|
|
```
|
|
|
|
## Cluster
|
|
|
|
Define a Kubernetes cluster using the module `digital-ocean/container-linux/kubernetes`.
|
|
|
|
```tf
|
|
module "digital-ocean-nemo" {
|
|
source = "git::https://github.com/poseidon/typhoon//digital-ocean/container-linux/kubernetes?ref=v1.15.2"
|
|
|
|
# Digital Ocean
|
|
cluster_name = "nemo"
|
|
region = "nyc3"
|
|
dns_zone = "digital-ocean.example.com"
|
|
|
|
# configuration
|
|
ssh_fingerprints = ["d7:9d:79:ae:56:32:73:79:95:88:e3:a2:ab:5d:45:e7"]
|
|
asset_dir = "/home/user/.secrets/clusters/nemo"
|
|
|
|
# optional
|
|
worker_count = 2
|
|
}
|
|
```
|
|
|
|
Reference the [variables docs](#variables) or the [variables.tf](https://github.com/poseidon/typhoon/blob/master/digital-ocean/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
|
|
```
|
|
|
|
## 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: 54 to add, 0 to change, 0 to destroy.
|
|
```
|
|
|
|
Apply the changes to create the cluster.
|
|
|
|
```sh
|
|
$ terraform apply
|
|
module.digital-ocean-nemo.null_resource.bootkube-start: Still creating... (30s elapsed)
|
|
module.digital-ocean-nemo.null_resource.bootkube-start: Provisioning with 'remote-exec'...
|
|
...
|
|
module.digital-ocean-nemo.null_resource.bootkube-start: Still creating... (6m20s elapsed)
|
|
module.digital-ocean-nemo.null_resource.bootkube-start: Creation complete (ID: 7599298447329218468)
|
|
|
|
Apply complete! Resources: 54 added, 0 changed, 0 destroyed.
|
|
```
|
|
|
|
In 3-6 minutes, the Kubernetes cluster will be ready.
|
|
|
|
## Verify
|
|
|
|
[Install kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl/) on your system. Use the generated `kubeconfig` credentials to access the Kubernetes cluster and list nodes.
|
|
|
|
```
|
|
$ export KUBECONFIG=/home/user/.secrets/clusters/nemo/auth/kubeconfig
|
|
$ kubectl get nodes
|
|
NAME STATUS ROLES AGE VERSION
|
|
10.132.110.130 Ready controller,master 10m v1.15.2
|
|
10.132.115.81 Ready node 10m v1.15.2
|
|
10.132.124.107 Ready node 10m v1.15.2
|
|
```
|
|
|
|
List the pods.
|
|
|
|
```
|
|
NAMESPACE NAME READY STATUS RESTARTS AGE
|
|
kube-system coredns-1187388186-ld1j7 1/1 Running 0 11m
|
|
kube-system coredns-1187388186-rdhf7 1/1 Running 0 11m
|
|
kube-system flannel-1cq1v 2/2 Running 0 11m
|
|
kube-system flannel-hq9t0 2/2 Running 1 11m
|
|
kube-system flannel-v0g9w 2/2 Running 0 11m
|
|
kube-system kube-apiserver-n10qr 1/1 Running 0 11m
|
|
kube-system kube-controller-manager-3271970485-37gtw 1/1 Running 1 11m
|
|
kube-system kube-controller-manager-3271970485-p52t5 1/1 Running 0 11m
|
|
kube-system kube-proxy-6kxjf 1/1 Running 0 11m
|
|
kube-system kube-proxy-fh3td 1/1 Running 0 11m
|
|
kube-system kube-proxy-k35rc 1/1 Running 0 11m
|
|
kube-system kube-scheduler-3895335239-2bc4c 1/1 Running 0 11m
|
|
kube-system kube-scheduler-3895335239-b7q47 1/1 Running 1 11m
|
|
kube-system pod-checkpointer-pr1lq 1/1 Running 0 11m
|
|
kube-system pod-checkpointer-pr1lq-10.132.115.81 1/1 Running 0 10m
|
|
```
|
|
|
|
## 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/digital-ocean/container-linux/kubernetes/variables.tf) source.
|
|
|
|
### Required
|
|
|
|
| Name | Description | Example |
|
|
|:-----|:------------|:--------|
|
|
| cluster_name | Unique cluster name (prepended to dns_zone) | nemo |
|
|
| region | Digital Ocean region | nyc1, sfo2, fra1, tor1 |
|
|
| dns_zone | Digital Ocean domain (i.e. DNS zone) | do.example.com |
|
|
| ssh_fingerprints | SSH public key fingerprints | ["d7:9d..."] |
|
|
| asset_dir | Path to a directory where generated assets should be placed (contains secrets) | /home/user/.secrets/nemo |
|
|
|
|
#### DNS Zone
|
|
|
|
Clusters create DNS A records `${cluster_name}.${dns_zone}` to resolve to controller droplets (round robin). This FQDN is used by workers and `kubectl` to access the apiserver(s). In this example, the cluster's apiserver would be accessible at `nemo.do.example.com`.
|
|
|
|
You'll need a registered domain name or delegated subdomain in Digital Ocean Domains (i.e. DNS zones). You can set this up once and create many clusters with unique names.
|
|
|
|
```tf
|
|
# Declare a DigitalOcean record to also create a zone file
|
|
resource "digitalocean_domain" "zone-for-clusters" {
|
|
name = "do.example.com"
|
|
ip_address = "8.8.8.8"
|
|
}
|
|
```
|
|
|
|
!!! tip ""
|
|
If you have an existing domain name with a zone file elsewhere, just delegate a subdomain that can be managed on DigitalOcean (e.g. do.mydomain.com) and [update nameservers](https://www.digitalocean.com/community/tutorials/how-to-set-up-a-host-name-with-digitalocean).
|
|
|
|
#### SSH Fingerprints
|
|
|
|
DigitalOcean droplets are created with your SSH public key "fingerprint" (i.e. MD5 hash) to allow access. If your SSH public key is at `~/.ssh/id_rsa`, find the fingerprint with,
|
|
|
|
```bash
|
|
ssh-keygen -E md5 -lf ~/.ssh/id_rsa.pub | awk '{print $2}'
|
|
MD5:d7:9d:79:ae:56:32:73:79:95:88:e3:a2:ab:5d:45:e7
|
|
```
|
|
|
|
If you use `ssh-agent` (e.g. Yubikey for SSH), find the fingerprint with,
|
|
|
|
```
|
|
ssh-add -l -E md5
|
|
2048 MD5:d7:9d:79:ae:56:32:73:79:95:88:e3:a2:ab:5d:45:e7 cardno:000603633110 (RSA)
|
|
```
|
|
|
|
Digital Ocean requires the SSH public key be uploaded to your account, so you may also find the fingerprint under Settings -> Security. Finally, if you don't have an SSH key, [create one now](https://help.github.com/articles/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent/).
|
|
|
|
### Optional
|
|
|
|
| Name | Description | Default | Example |
|
|
|:-----|:------------|:--------|:--------|
|
|
| controller_count | Number of controllers (i.e. masters) | 1 | 1 |
|
|
| worker_count | Number of workers | 1 | 3 |
|
|
| controller_type | Droplet type for controllers | s-2vcpu-2gb | s-2vcpu-2gb, s-2vcpu-4gb, s-4vcpu-8gb, ... |
|
|
| worker_type | Droplet type for workers | s-1vcpu-2gb | s-1vcpu-2gb, s-2vcpu-2gb, ... |
|
|
| image | Container Linux image for instances | "coreos-stable" | coreos-stable, coreos-beta, coreos-alpha |
|
|
| 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 | "flannel" | "flannel" or "calico" (experimental) |
|
|
| 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" |
|
|
| cluster_domain_suffix | FQDN suffix for Kubernetes services answered by coredns. | "cluster.local" | "k8s.example.com" |
|
|
|
|
Check the list of valid [droplet types](https://developers.digitalocean.com/documentation/changelog/api-v2/new-size-slugs-for-droplet-plan-changes/) or use `doctl compute size list`.
|
|
|
|
!!! warning
|
|
Do not choose a `controller_type` smaller than 2GB. Smaller droplets are not sufficient for running a controller and bootstrapping will fail.
|