Deploy in a few minutes an high available Kubernetes cluster on Amazon AWS using mixed on-demand and spot instances.
Please note, this is only an example on how to Deploy a Kubernetes cluster. For a production environment you should use EKS or ECS.
The scope of this repo is to show all the AWS components needed to deploy a high available K8s cluster.
- Terraform - Terraform is an open-source infrastructure as code software tool that provides a consistent CLI workflow to manage hundreds of cloud services. Terraform codifies cloud APIs into declarative configuration files.
- Amazon AWS Account - Amazon AWS account with billing enabled
- kubectl - The Kubernetes command-line tool (optional)
- aws cli optional
You need also:
- one VPC with private and public subnets
- one ssh key already uploaded on your AWS account
For VPC you can refer to this repository.
Note that this tutorial uses AWS resources that are outside the AWS free tier, so be careful!
Clone this repo and go in the example/ directory:
git clone https://github.com/garutilorenzo/k8s-aws-terraform-cluster cd k8s-aws-terraform-cluster/example/ Now you have to edit the main.tf file and you have to create the terraform.tfvars file. For more detail see AWS provider setup and Pre flight checklist.
Or if you prefer you can create an new empty directory in your workspace and create this three files:
terraform.tfvarsmain.tfprovider.tf
The main.tf file will look like:
variable "AWS_ACCESS_KEY" { } variable "AWS_SECRET_KEY" { } variable "environment" { default = "staging" } variable "AWS_REGION" { default = "<CHANGE_ME>" } variable "my_public_ip_cidr" { default = "<CHANGE_ME>" } variable "vpc_cidr_block" { default = "<CHANGE_ME>" } variable "certmanager_email_address" { default = "<CHANGE_ME>" } variable "ssk_key_pair_name" { default = "<CHANGE_ME>" } module "private-vpc" { region = var.AWS_REGION my_public_ip_cidr = var.my_public_ip_cidr vpc_cidr_block = var.vpc_cidr_block environment = var.environment source = "github.com/garutilorenzo/aws-terraform-examples/private-vpc" } output "private_subnets_ids" { value = module.private-vpc.private_subnet_ids } output "public_subnets_ids" { value = module.private-vpc.public_subnet_ids } output "vpc_id" { value = module.private-vpc.vpc_id } module "k8s-cluster" { ssk_key_pair_name = var.ssk_key_pair_name environment = var.environment vpc_id = module.private-vpc.vpc_id vpc_private_subnets = module.private-vpc.private_subnet_ids vpc_public_subnets = module.private-vpc.public_subnet_ids vpc_subnet_cidr = var.vpc_cidr_block my_public_ip_cidr = var.my_public_ip_cidr create_extlb = true install_nginx_ingress = true efs_persistent_storage = true expose_kubeapi = true install_certmanager = true certmanager_email_address = var.certmanager_email_address source = "github.com/garutilorenzo/k8s-aws-terraform-cluster" } output "k8s_dns_name" { value = module.k8s-cluster.k8s_dns_name } output "k8s_server_private_ips" { value = module.k8s-cluster.k8s_server_private_ips } output "k8s_workers_private_ips" { value = module.k8s-cluster.k8s_workers_private_ips } For all the possible variables see Pre flight checklist
The provider.tf will look like:
provider "aws" { region = var.AWS_REGION access_key = var.AWS_ACCESS_KEY secret_key = var.AWS_SECRET_KEY } The terraform.tfvars will look like:
AWS_ACCESS_KEY = "xxxxxxxxxxxxxxxxx" AWS_SECRET_KEY = "xxxxxxxxxxxxxxxxx" Now we can init terraform with:
terraform init Initializing modules... - k8s-cluster in .. Initializing the backend... Initializing provider plugins... - Finding latest version of hashicorp/template... - Finding latest version of hashicorp/aws... - Installing hashicorp/template v2.2.0... - Installed hashicorp/template v2.2.0 (signed by HashiCorp) - Installing hashicorp/aws v4.9.0... - Installed hashicorp/aws v4.9.0 (signed by HashiCorp) Terraform has created a lock file .terraform.lock.hcl to record the provider selections it made above. Include this file in your version control repository so that Terraform can guarantee to make the same selections by default when you run "terraform init" in the future. Terraform has been successfully initialized! You may now begin working with Terraform. Try running "terraform plan" to see any changes that are required for your infrastructure. All Terraform commands should now work. If you ever set or change modules or backend configuration for Terraform, rerun this command to reinitialize your working directory. If you forget, other commands will detect it and remind you to do so if necessary. Follow the prerequisites step on this link. In your workspace folder or in the examples directory of this repo create a file named terraform.tfvars:
AWS_ACCESS_KEY = "xxxxxxxxxxxxxxxxx" AWS_SECRET_KEY = "xxxxxxxxxxxxxxxxx" Once you have created the terraform.tfvars file edit the main.tf file (always in the example/ directory) and set the following variables:
| Var | Required | Desc |
|---|---|---|
region | yes | set the correct AWS region based on your needs |
environment | yes | Current work environment (Example: staging/dev/prod). This value is used for tag all the deployed resources |
ssk_key_pair_name | yes | Name of the ssh key to use |
my_public_ip_cidr | yes | your public ip in cidr format (Example: 195.102.xxx.xxx/32) |
vpc_id | yes | ID of the VPC to use. You can find your vpc_id in your AWS console (Example: vpc-xxxxx) |
vpc_private_subnets | yes | List of private subnets to use. This subnets are used for the public LB You can find the list of your vpc subnets in your AWS console (Example: subnet-xxxxxx) |
vpc_public_subnets | yes | List of public subnets to use. This subnets are used for the EC2 instances and the private LB. You can find the list of your vpc subnets in your AWS console (Example: subnet-xxxxxx) |
vpc_subnet_cidr | yes | Your subnet CIDR. You can find the VPC subnet CIDR in your AWS console (Example: 172.31.0.0/16) |
common_prefix | no | Prefix used in all resource names/tags. Default: k8s |
ec2_associate_public_ip_address | no | Assign or not a pulic ip to the EC2 instances. Default: false |
instance_profile_name | no | Instance profile name. Default: K8sInstanceProfile |
ami | no | Ami image name. Default: ami-0a2616929f1e63d91, ubuntu 20.04 |
default_instance_type | no | Default instance type used by the Launch template. Default: t3.large |
instance_types | no | Array of instances used by the ASG. Dfault: { asg_instance_type_1 = "t3.large", asg_instance_type_3 = "m4.large", asg_instance_type_4 = "t3a.large" } |
k8s_version | no | Kubernetes version to install |
k8s_pod_subnet | no | Kubernetes pod subnet managed by the CNI (Flannel). Default: 10.244.0.0/16 |
k8s_service_subnet | no | Kubernetes pod service managed by the CNI (Flannel). Default: 10.96.0.0/12 |
k8s_dns_domain | no | Internal kubernetes DNS domain. Default: cluster.local |
kube_api_port | no | Kubernetes api port. Default: 6443 |
k8s_server_desired_capacity | no | Desired number of k8s servers. Default 3 |
k8s_server_min_capacity | no | Min number of k8s servers: Default 4 |
k8s_server_max_capacity | no | Max number of k8s servers: Default 3 |
k8s_worker_desired_capacity | no | Desired number of k8s workers. Default 3 |
k8s_worker_min_capacity | no | Min number of k8s workers: Default 4 |
k8s_worker_max_capacity | no | Max number of k8s workers: Default 3 |
cluster_name | no | Kubernetes cluster name. Default: k8s-cluster |
install_nginx_ingress | no | Install or not nginx ingress controller. Default: false |
nginx_ingress_release | no | Nginx ingress release to install. Default: v1.8.1 |
install_certmanager | no | Boolean value, install cert manager "Cloud native certificate management". Default: true |
certmanager_email_address | no | Email address used for signing https certificates. Defaul: changeme@example.com |
certmanager_release | no | Cert manager release. Default: v1.12.2 |
efs_persistent_storage | no | Deploy EFS for persistent sotrage |
efs_csi_driver_release | no | EFS CSI driver Release: v1.5.8 |
extlb_listener_http_port | no | HTTP nodeport where nginx ingress controller will listen. Default: 30080 |
extlb_listener_https_port | no | HTTPS nodeport where nginx ingress controller will listen. Default 30443 |
extlb_http_port | no | External LB HTTP listen port. Default: 80 |
extlb_https_port | no | External LB HTTPS listen port. Default 443 |
expose_kubeapi | no | Boolean value, default false. Expose or not the kubeapi server to the internet. Access is granted only from my_public_ip_cidr for security reasons. |
The final infrastructure will be made by:
- two autoscaling group, one for the kubernetes master nodes and one for the worker nodes
- two launch template, used by the asg
- one internal load balancer (L4) that will route traffic to Kubernetes servers
- one external load balancer (L4) that will route traffic to Kubernetes workers
- one security group that will allow traffic from the VPC subnet CIDR on all the k8s ports (kube api, nginx ingress node port etc)
- one security group that will allow traffic from all the internet into the public load balancer (L4) on port 80 and 443
- four secrets that will store k8s join tokens
Optional resources:
- EFS storage to persist data
The installation of K8s id done by kubeadm. In this installation Containerd is used as CRI and flannel is used as CNI.
You can optionally install Nginx ingress controller.
To install Nginx ingress set the variable install_nginx_ingress to yes (default no).
You can optionally install Nginx ingress controller To enable the Nginx deployment set install_nginx_ingress variable to true.
The installation is the bare metal installation, the ingress controller then is exposed via a NodePort Service.
--- apiVersion: v1 kind: Service metadata: name: ingress-nginx-controller namespace: ingress-nginx spec: ports: - appProtocol: http name: http port: 80 protocol: TCP targetPort: http nodePort: ${extlb_listener_http_port} - appProtocol: https name: https port: 443 protocol: TCP targetPort: https nodePort: ${extlb_listener_https_port} selector: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx type: NodePortTo get the real ip address of the clients using a public L4 load balancer we need to use the proxy protocol feature of nginx ingress controller:
--- apiVersion: v1 data: allow-snippet-annotations: "true" enable-real-ip: "true" proxy-real-ip-cidr: "0.0.0.0/0" proxy-body-size: "20m" use-proxy-protocol: "true" kind: ConfigMap metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: ${nginx_ingress_release} name: ingress-nginx-controller namespace: ingress-nginxcert-manager is used to issue certificates from a variety of supported source.
We are now ready to deploy our infrastructure. First we ask terraform to plan the execution with:
terraform plan ... ... Plan: 73 to add, 0 to change, 0 to destroy. Changes to Outputs: + k8s_dns_name = [ + (known after apply), ] ~ k8s_server_private_ips = [ - [], + (known after apply), ] ~ k8s_workers_private_ips = [ - [], + (known after apply), ] + private_subnets_ids = [ + (known after apply), + (known after apply), + (known after apply), ] + public_subnets_ids = [ + (known after apply), + (known after apply), + (known after apply), ] + vpc_id = (known after apply) ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── Note: You didn't use the -out option to save this plan, so Terraform can't guarantee to take exactly these actions if you run "terraform apply" now. now we can deploy our resources with:
terraform apply ... Plan: 73 to add, 0 to change, 0 to destroy. Changes to Outputs: + k8s_dns_name = [ + (known after apply), ] ~ k8s_server_private_ips = [ - [], + (known after apply), ] ~ k8s_workers_private_ips = [ - [], + (known after apply), ] + private_subnets_ids = [ + (known after apply), + (known after apply), + (known after apply), ] + public_subnets_ids = [ + (known after apply), + (known after apply), + (known after apply), ] + vpc_id = (known after apply) Do you want to perform these actions? Terraform will perform the actions described above. Only 'yes' will be accepted to approve. Enter a value: yes ... ... Apply complete! Resources: 73 added, 0 changed, 0 destroyed. Outputs: k8s_dns_name = "k8s-ext-<REDACTED>.elb.amazonaws.com" k8s_server_private_ips = [ tolist([ "172.x.x.x", "172.x.x.x", "172.x.x.x", ]), ] k8s_workers_private_ips = [ tolist([ "172.x.x.x", "172.x.x.x", "172.x.x.x", ]), ] private_subnets_ids = [ "subnet-xxxxxxxxxxxxxxxxx", "subnet-xxxxxxxxxxxxxxxxx", "subnet-xxxxxxxxxxxxxxxxx", ] public_subnets_ids = [ "subnet-xxxxxxxxxxxxxxxxx", "subnet-xxxxxxxxxxxxxxxxx", "subnet-xxxxxxxxxxxxxxxxx", ] vpc_id = "vpc-xxxxxxxxxxxxxxxxx" Now on one master node (connect via AWS SSM) you can check the status of the cluster with:
ubuntu@i-04d089ed896cfafe1:~$ sudo su - root@i-04d089ed896cfafe1:~# kubectl get nodes NAME STATUS ROLES AGE VERSION i-0033b408f7a1d55f3 Ready control-plane,master 3m33s v1.23.5 i-0121c2149821379cc Ready <none> 4m16s v1.23.5 i-04d089ed896cfafe1 Ready control-plane,master 4m53s v1.23.5 i-072bf7de2e94e6f2d Ready <none> 4m15s v1.23.5 i-09b23242f40eabcca Ready control-plane,master 3m56s v1.23.5 i-0cb1e2e7784768b22 Ready <none> 3m57s v1.23.5 root@i-04d089ed896cfafe1:~# kubectl get ns NAME STATUS AGE cert-manager Active 85s default Active 4m55s ingress-nginx Active 87s # <- ingress controller ns kube-flannel Active 4m32s kube-node-lease Active 4m55s kube-public Active 4m56s kube-system Active 4m56s root@i-04d089ed896cfafe1:~# kubectl get pods --all-namespaces NAMESPACE NAME READY STATUS RESTARTS AGE cert-manager cert-manager-66d9545484-h4d9h 1/1 Running 0 47s cert-manager cert-manager-cainjector-7d8b6bd6fb-zl7sg 1/1 Running 0 47s cert-manager cert-manager-webhook-669b96dcfd-b5pgk 1/1 Running 0 47s ingress-nginx ingress-nginx-admission-create-g62rk 0/1 Completed 0 50s ingress-nginx ingress-nginx-admission-patch-n9tc5 0/1 Completed 0 50s ingress-nginx ingress-nginx-controller-5c778bffff-bmk2c 1/1 Running 0 50s kube-flannel kube-flannel-ds-5fvx9 1/1 Running 0 3m45s kube-flannel kube-flannel-ds-bvqkc 1/1 Running 1 (3m13s ago) 3m35s kube-flannel kube-flannel-ds-hgxtn 1/1 Running 1 (111s ago) 2m40s kube-flannel kube-flannel-ds-kp6tl 1/1 Running 0 3m27s kube-flannel kube-flannel-ds-nvbbg 1/1 Running 0 3m55s kube-flannel kube-flannel-ds-rhsqq 1/1 Running 0 2m42s kube-system aws-node-termination-handler-478lj 1/1 Running 0 26s kube-system aws-node-termination-handler-5bk96 1/1 Running 0 26s kube-system aws-node-termination-handler-bkzrf 1/1 Running 0 26s kube-system aws-node-termination-handler-cx5ps 1/1 Running 0 26s kube-system aws-node-termination-handler-dfr44 1/1 Running 0 26s kube-system aws-node-termination-handler-vcq7z 1/1 Running 0 26s kube-system coredns-5d78c9869d-n7jcq 1/1 Running 0 4m1s kube-system coredns-5d78c9869d-w9k5j 1/1 Running 0 4m1s kube-system efs-csi-controller-74695cd876-66bw5 3/3 Running 0 28s kube-system efs-csi-controller-74695cd876-hl9g7 3/3 Running 0 28s kube-system efs-csi-node-7wgff 3/3 Running 0 27s kube-system efs-csi-node-9v4nv 3/3 Running 0 27s kube-system efs-csi-node-mjz2r 3/3 Running 0 27s kube-system efs-csi-node-n4npv 3/3 Running 0 27s kube-system efs-csi-node-pmpnc 3/3 Running 0 27s kube-system efs-csi-node-s4prq 3/3 Running 0 27s kube-system etcd-i-012c258d537d5ec2f 1/1 Running 0 4m4s kube-system etcd-i-018fb1214f9fe07fe 1/1 Running 0 3m7s kube-system etcd-i-0f73570d6dddb6d0b 1/1 Running 0 3m27s kube-system kube-apiserver-i-012c258d537d5ec2f 1/1 Running 0 4m6s kube-system kube-apiserver-i-018fb1214f9fe07fe 1/1 Running 1 (3m4s ago) 3m4s kube-system kube-apiserver-i-0f73570d6dddb6d0b 1/1 Running 0 3m26s kube-system kube-controller-manager-i-012c258d537d5ec2f 1/1 Running 1 (3m15s ago) 4m7s kube-system kube-controller-manager-i-018fb1214f9fe07fe 1/1 Running 0 2m9s kube-system kube-controller-manager-i-0f73570d6dddb6d0b 1/1 Running 0 3m26s kube-system kube-proxy-4lwgv 1/1 Running 0 2m40s kube-system kube-proxy-9hgtr 1/1 Running 0 3m27s kube-system kube-proxy-d6zzp 1/1 Running 0 4m1s kube-system kube-proxy-jwb8x 1/1 Running 0 3m35s kube-system kube-proxy-q2ctc 1/1 Running 0 2m42s kube-system kube-proxy-sgn7r 1/1 Running 0 3m45s kube-system kube-scheduler-i-012c258d537d5ec2f 1/1 Running 1 (3m12s ago) 4m6s kube-system kube-scheduler-i-018fb1214f9fe07fe 1/1 Running 0 3m1s kube-system kube-scheduler-i-0f73570d6dddb6d0b 1/1 Running 0 3m26s We can now test the public load balancer, nginx ingress controller and the security group ingress rules. On your local PC run:
curl -k -v https://k8s-ext-<REDACTED>.elb.amazonaws.com/ * Trying 34.x.x.x:443... * TCP_NODELAY set * Connected to k8s-ext-<REDACTED>.elb.amazonaws.com (34.x.x.x) port 443 (#0) * ALPN, offering h2 * ALPN, offering http/1.1 * successfully set certificate verify locations: * CAfile: /etc/ssl/certs/ca-certificates.crt CApath: /etc/ssl/certs * TLSv1.3 (OUT), TLS handshake, Client hello (1): * TLSv1.3 (IN), TLS handshake, Server hello (2): * TLSv1.2 (IN), TLS handshake, Certificate (11): * TLSv1.2 (IN), TLS handshake, Server key exchange (12): * TLSv1.2 (IN), TLS handshake, Server finished (14): * TLSv1.2 (OUT), TLS handshake, Client key exchange (16): * TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1): * TLSv1.2 (OUT), TLS handshake, Finished (20): * TLSv1.2 (IN), TLS handshake, Finished (20): * SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256 * ALPN, server accepted to use h2 * Server certificate: * subject: C=IT; ST=Italy; L=Brescia; O=GL Ltd; OU=IT; CN=testlb.domainexample.com; emailAddress=email@you.com * start date: Apr 11 08:20:12 2022 GMT * expire date: Apr 11 08:20:12 2023 GMT * issuer: C=IT; ST=Italy; L=Brescia; O=GL Ltd; OU=IT; CN=testlb.domainexample.com; emailAddress=email@you.com * SSL certificate verify result: self signed certificate (18), continuing anyway. * Using HTTP2, server supports multi-use * Connection state changed (HTTP/2 confirmed) * Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0 * Using Stream ID: 1 (easy handle 0x55c6560cde10) > GET / HTTP/2 > Host: k8s-ext-<REDACTED>.elb.amazonaws.com > user-agent: curl/7.68.0 > accept: */* > * Connection state changed (MAX_CONCURRENT_STREAMS == 128)! < HTTP/2 404 < date: Tue, 12 Apr 2022 10:08:18 GMT < content-type: text/html < content-length: 146 < strict-transport-security: max-age=15724800; includeSubDomains < <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx</center> </body> </html> * Connection #0 to host k8s-ext-<REDACTED>.elb.amazonaws.com left intact 404 is a correct response since the cluster is empty.
Deploy ECK on Kubernetes
terraform destroy