# AWS In this tutorial, we'll create a Kubernetes v1.8.5 cluster on AWS. We'll declare a Kubernetes cluster in Terraform using the Typhoon Terraform module. On apply, a VPC, gateway, subnets, auto-scaling groups of controllers and workers, network load balancers for controllers and workers, and security groups will be created. Controllers and workers are provisioned to run a `kubelet`. A one-time [bootkube](https://github.com/kubernetes-incubator/bootkube) bootstrap schedules an `apiserver`, `scheduler`, `controller-manager`, and `kube-dns` on controllers and runs `kube-proxy` and `calico` or `flannel` on each node. A generated `kubeconfig` provides `kubectl` access to the cluster. ## Requirements * AWS Account and IAM credentials * AWS Route53 DNS Zone (registered Domain Name or delegated subdomain) * Terraform v0.10.x and [terraform-provider-ct](https://github.com/coreos/terraform-provider-ct) installed locally ## Terraform Setup Install [Terraform](https://www.terraform.io/downloads.html) v0.10.x on your system. ```sh $ terraform version Terraform v0.10.7 ``` 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 AWS IAM dashboard and find your IAM user. Select "Security Credentials" and create an access key. Save the id and secret to a file that can be referenced in configs. ``` [default] aws_access_key_id = xxx aws_secret_access_key = yyy ``` Configure the AWS provider to use your access key credentials in a `providers.tf` file. ```tf provider "aws" { region = "eu-central-1" shared_credentials_file = "/home/user/.config/aws/credentials" } ``` Additional configuration options are described in the `aws` provider [docs](https://www.terraform.io/docs/providers/aws/). !!! tip Regions are listed in [docs](http://docs.aws.amazon.com/general/latest/gr/rande.html#ec2_region) or with `aws ec2 describe-regions`. ## Cluster Define a Kubernetes cluster using the module `aws/container-linux/kubernetes`. ```tf module "aws-tempest" { source = "git::https://github.com/poseidon/typhoon//aws/container-linux/kubernetes" cluster_name = "tempest" # AWS dns_zone = "aws.example.com" dns_zone_id = "Z3PAABBCFAKEC0" controller_count = 1 controller_type = "t2.medium" worker_count = 2 worker_type = "t2.small" ssh_authorized_key = "ssh-rsa AAAAB3Nz..." # bootkube asset_dir = "/home/user/.secrets/clusters/tempest" } ``` Reference the [variables docs](#variables) or the [variables.tf](https://github.com/poseidon/typhoon/blob/master/aws/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 `terraform 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=v0.9.1 (update) ``` Plan the resources to be created. ```sh $ terraform plan Plan: 98 to add, 0 to change, 0 to destroy. ``` Apply the changes to create the cluster. ```sh $ terraform apply ... module.aws-tempest.null_resource.bootkube-start: Still creating... (4m50s elapsed) module.aws-tempest.null_resource.bootkube-start: Still creating... (5m0s elapsed) module.aws-tempest.null_resource.bootkube-start: Creation complete after 11m8s (ID: 3961816482286168143) Apply complete! Resources: 98 added, 0 changed, 0 destroyed. ``` In 4-8 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/tempest/auth/kubeconfig $ kubectl get nodes NAME STATUS AGE VERSION ip-10-0-12-221 Ready 34m v1.8.5 ip-10-0-19-112 Ready 34m v1.8.5 ip-10-0-4-22 Ready 34m v1.8.5 ``` List the pods. ``` $ kubectl get pods --all-namespaces NAMESPACE NAME READY STATUS RESTARTS AGE kube-system calico-node-1m5bf 2/2 Running 0 34m kube-system calico-node-7jmr1 2/2 Running 0 34m kube-system calico-node-bknc8 2/2 Running 0 34m kube-system kube-apiserver-4mjbk 1/1 Running 0 34m kube-system kube-controller-manager-3597210155-j2jbt 1/1 Running 1 34m kube-system kube-controller-manager-3597210155-j7g7x 1/1 Running 0 34m kube-system kube-dns-1187388186-wx1lg 3/3 Running 0 34m kube-system kube-proxy-14wxv 1/1 Running 0 34m kube-system kube-proxy-9vxh2 1/1 Running 0 34m kube-system kube-proxy-sbbsh 1/1 Running 0 34m kube-system kube-scheduler-3359497473-5plhf 1/1 Running 0 34m kube-system kube-scheduler-3359497473-r7zg7 1/1 Running 1 34m kube-system pod-checkpointer-4kxtl 1/1 Running 0 34m kube-system pod-checkpointer-4kxtl-ip-10-0-12-221 1/1 Running 0 33m ``` ## 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) | "tempest" | | dns_zone | AWS Route53 DNS zone | "aws.example.com" | | dns_zone_id | AWS Route53 DNS zone id | "Z3PAABBCFAKEC0" | | ssh_authorized_key | SSH public key for ~/.ssh_authorized_keys | "ssh-rsa AAAAB3NZ..." | | os_channel | Container Linux AMI channel | stable, beta, alpha | | asset_dir | Path to a directory where generated assets should be placed (contains secrets) | "/home/user/.secrets/clusters/tempest" | #### 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 `tempest.aws.example.com`. You'll need a registered domain name or subdomain registered in a AWS Route53 DNS zone. You can set this up once and create many clusters with unique names. ```tf resource "aws_route53_zone" "zone-for-clusters" { name = "aws.example.com." } ``` Reference the DNS zone id with `"${aws_route53_zone.zone-for-clusters.zone_id}"`. !!! tip "" If you have an existing domain name with a zone file elsewhere, just carve out a subdomain that can be managed on Route53 (e.g. aws.mydomain.com) and [update nameservers](http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/SOA-NSrecords.html). ### Optional | Name | Description | Default | Example | |:-----|:------------|:--------|:--------| | controller_count | Number of controllers (i.e. masters) | 1 | 1 | | controller_type | Controller EC2 instance type | "t2.small" | "t2.medium" | | worker_count | Number of workers | 1 | 3 | | worker_type | Worker EC2 instance type | "t2.small" | "t2.medium" | | disk_size | Size of the EBS volume in GB | "40" | "100" | | networking | Choice of networking provider | "calico" | "calico" or "flannel" | | network_mtu | CNI interface MTU (calico only) | 1480 | 8981 | | host_cidr | CIDR range to assign to EC2 instances | "10.0.0.0/16" | "10.1.0.0/16" | | pod_cidr | CIDR range to assign to Kubernetes pods | "10.2.0.0/16" | "10.22.0.0/16" | | service_cidr | CIDR 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 kube-dns. | "cluster.local" | "k8s.example.com" | Check the list of valid [instance types](https://aws.amazon.com/ec2/instance-types/). !!! tip "MTU" If your EC2 instance type supports [Jumbo frames](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/network_mtu.html#jumbo_frame_instances) (most do), we recommend you change the `network_mtu` to 8991! You will get better pod-to-pod bandwidth.