tf-k8s-learn-kubeadm

This Terraform module creates AWS resources to learn for CKA and experiment with kubeadm / self-managed K8s.

Resources

• OPTIONAL: AWS Key Pair (you can use a pre-existing one, too)
• VPC
  • Public Subnets
    • Internet Gateway
  • Private Subnets
    • NAT Gateway (single one for all AZs to save costs)
• Classic Load Balancer
  • etcd
  • kube-apiserver
• UserData
  • ssh-multi.sh tmux script
  • Install useful tools:
    • curl
    • etcdctl
    • jq
    • wget
    • yq
• EC2 Instances (NO AUTOSCALING!)
  • Bastion (provisioned with your private SSH Key and populated SSH Config)
  • etcd
  • controller
  • worker

Examples

Set variables in your local terraform.tfvars file to match your needs.

Use Ubuntu 20.04 LTS instead of default 18.04 and pre-existing AWS Key Pair and SSH Key path:

owner                = "johndoe"
ssh_private_key_path = "$HOME/.ssh/id_rsa-customkey"
key_pair_name        = "my-key-pair-name"
ubuntu_release       = "focal-20.04"

Set custom instance types (default: t3a.small):

owner                 = "johndoe"
bastion_instance_type = "t3a.micro"
etcd_instance_type    = "t3a.medium"
master_instance_type  = "t3a.medium"
worker_instance_type  = "t3a.large"

Terraform Docs

Requirements

No requirements.

Providers

Name	Version
aws	n/a
http	n/a

Inputs

Name	Description	Type	Default	Required
aws_region	AWS Region to use for all resources	string	"eu-central-1"	no
bastion_instance_type	Bastion: EC2 Instance Type	string	"t3a.small"	no
bastion_volume_size	bastion - EBS root volume size in GB	number	30	no
cfssl_version	cfssl version to install in UserData	string	"1.4.1"	no
controller_instance_type	controller: EC2 Instance Type	string	"t3a.small"	no
controller_volume_size	controller - EBS root volume size in GB	number	30	no
etcd_instance_type	etcd: EC2 Instance Type	string	"t3a.small"	no
etcd_version	etcd / etcdctl version to install in UserData	string	"v3.4.13"	no
etcd_volume_size	etcd - EBS root volume size in GB	number	30	no
key_pair_name	Preexisting AWS Key Pair name for SSH (leave emty to generate new AWS Key Pair)	string	""	no
number_azs	Number of AWS Availability Zones to use for every subnet	number	3	no
owner	Tag 'Owner' to be used for all resources	string	n/a	yes
ssh_private_key_path	SSH Private Key path on your workstatio (must match 'key_pair_name' SSH Key)	string	"$HOME/.ssh/id_rsa"	no
tags	Tags to apply to resources	map(string)	{ "ManagedBy": "terraform", "Name": "cka-kubeadm", "Project": "cka-kubeadm" }	no
timezone	TImezone to set for alle instances	string	"Europe/Berlin"	no
ubuntu_release	Ubuntu release name and version for AMI data source search (<short-name>-<version-number>)	string	"bionic-18.04"	no
vpc_cidr	AWS VPC CIDR network block (e.g. 10.0.0.0/16)	string	"10.0.0.0/16"	no
worker_instance_type	Worker: EC2 Instance Type	string	"t3a.small"	no
worker_volume_size	Worker - EBS root volume size in GB	number	30	no

Outputs

Name	Description
ami	AMI description
bastion_public_ip	Bastion Host Public IPv4 address to connect to
lb_etcd_dns	etcd Load Balancer DNS
lb_kube_apiserver_dns	kube-apiserver Load Balancer DNS
workstation_ip	Your workstation's IP address