terraform-aws-eks/README.md

terraform-aws-eks

A terraform module to create a managed Kubernetes cluster on AWS EKS. Available through the Terraform registry. Inspired by and adapted from this doc and its source code. Read the AWS docs on EKS to get connected to the k8s dashboard.

Assumptions

• You want to create an EKS cluster and an autoscaling group of workers for the cluster.
• You want these resources to exist within security groups that allow communication and coordination. These can be user provided or created within the module.
• You've created a Virtual Private Cloud (VPC) and subnets where you intend to put the EKS resources. The VPC satisfies EKS requirements.
• If manage_aws_auth = true, it's required that both kubectl (>=1.10) and aws-iam-authenticator are installed and on your shell's PATH.

Usage example

A full example leveraging other community modules is contained in the examples/basic directory.

data "aws_eks_cluster" "cluster" {
  name = module.eks.cluster_id
}

data "aws_eks_cluster_auth" "cluster" {
  name = module.eks.cluster_id
}

provider "kubernetes" {
  host                   = data.aws_eks_cluster.cluster.endpoint
  cluster_ca_certificate = base64decode(data.aws_eks_cluster.cluster.certificate_authority.0.data)
  token                  = data.aws_eks_cluster_auth.cluster.token
  load_config_file       = false
  version                = "~> 1.9"
}

module "my-cluster" {
  source          = "terraform-aws-modules/eks/aws"
  cluster_name    = "my-cluster"
  cluster_version = "1.14"
  subnets         = ["subnet-abcde012", "subnet-bcde012a", "subnet-fghi345a"]
  vpc_id          = "vpc-1234556abcdef"

  worker_groups = [
    {
      instance_type = "m4.large"
      asg_max_size  = 5
    }
  ]
}

Conditional creation

Sometimes you need to have a way to create EKS resources conditionally but Terraform does not allow to use count inside module block, so the solution is to specify argument create_eks.

Using this feature and having manage_aws_auth=true (the default) requires to set up the kubernetes provider in a way that allows the data sources to not exist.

data "aws_eks_cluster" "cluster" {
  count = var.create_eks ? 1 : 0
  name  = module.eks.cluster_id
}

data "aws_eks_cluster_auth" "cluster" {
  count = var.create_eks ? 1 : 0
  name  = module.eks.cluster_id
}

# In case of not creating the cluster, this will be an incompletely configured, unused provider, which poses no problem.
provider "kubernetes" {
  host                   = element(concat(data.aws_eks_cluster.cluster[*].endpoint, list("")), 0)
  cluster_ca_certificate = base64decode(element(concat(data.aws_eks_cluster.cluster[*].certificate_authority.0.data, list("")), 0))
  token                  = element(concat(data.aws_eks_cluster_auth.cluster[*].token, list("")), 0)
  load_config_file       = false
  version                = "~> 1.10"
}

# This cluster will not be created
module "eks" {
  source = "terraform-aws-modules/eks/aws"

  create_eks = false
  # ... omitted
}

Other documentation

• Autoscaling: How to enable worker node autoscaling.
• Enable Docker Bridge Network: How to enable the docker bridge network when using the EKS-optimized AMI, which disables it by default.
• Spot instances: How to use spot instances with this module.
• IAM Permissions: Minimum IAM permissions needed to setup EKS Cluster.
• FAQ: Frequently Asked Questions

Testing

This module has been packaged with awspec tests through kitchen and kitchen-terraform. To run them:

1. Install rvm and the ruby version specified in the Gemfile.

2. Install bundler and the gems from our Gemfile:

   gem install bundler && bundle install
   

3. Ensure your AWS environment is configured (i.e. credentials and region) for test.

4. Test using bundle exec kitchen test from the root of the repo.

For now, connectivity to the kubernetes cluster is not tested but will be in the future. Once the test fixture has converged, you can query the test cluster from that terminal session with

kubectl get nodes --watch --kubeconfig kubeconfig

(using default settings config_output_path = "./" & write_kubeconfig = true)

Doc generation

Code formatting and documentation for variables and outputs is generated using pre-commit-terraform hooks which uses terraform-docs.

Follow these instructions to install pre-commit locally.

And install terraform-docs with go get github.com/segmentio/terraform-docs or brew install terraform-docs.

Contributing

Report issues/questions/feature requests on in the issues section.

Full contributing guidelines are covered here.

Change log

The changelog captures all important release notes.

Authors

Created by Brandon O'Connor - brandon@atscale.run. Maintained by Max Williams and Thierno IB. BARRY. Many thanks to the contributors listed here!

License

MIT Licensed. See LICENSE for full details.

Inputs

Name	Description	Type	Default	Required
attach_worker_autoscaling_policy	Whether to attach the module managed cluster autoscaling iam policy to the default worker IAM role. This requires manage_worker_autoscaling_policy = true	bool	"true"	no
attach_worker_cni_policy	Whether to attach the Amazon managed AmazonEKS_CNI_Policy IAM policy to the default worker IAM role. WARNING: If set false the permissions must be assigned to the aws-node DaemonSet pods via another method or nodes will not be able to join the cluster.	bool	"true"	no
cluster_create_security_group	Whether to create a security group for the cluster or attach the cluster to cluster_security_group_id.	bool	"true"	no
cluster_create_timeout	Timeout value when creating the EKS cluster.	string	"15m"	no
cluster_delete_timeout	Timeout value when deleting the EKS cluster.	string	"15m"	no
cluster_enabled_log_types	A list of the desired control plane logging to enable. For more information, see Amazon EKS Control Plane Logging documentation (https://docs.aws.amazon.com/eks/latest/userguide/control-plane-logs.html)	list(string)	[]	no
cluster_endpoint_private_access	Indicates whether or not the Amazon EKS private API server endpoint is enabled.	bool	"false"	no
cluster_endpoint_public_access	Indicates whether or not the Amazon EKS public API server endpoint is enabled.	bool	"true"	no
cluster_iam_role_name	IAM role name for the cluster. Only applicable if manage_cluster_iam_resources is set to false.	string	""	no
cluster_log_kms_key_id	If a KMS Key ARN is set, this key will be used to encrypt the corresponding log group. Please be sure that the KMS Key has an appropriate key policy (https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/encrypt-log-data-kms.html)	string	""	no
cluster_log_retention_in_days	Number of days to retain log events. Default retention - 90 days.	number	"90"	no
cluster_name	Name of the EKS cluster. Also used as a prefix in names of related resources.	string	n/a	yes
cluster_security_group_id	If provided, the EKS cluster will be attached to this security group. If not given, a security group will be created with necessary ingress/egress to work with the workers	string	""	no
cluster_version	Kubernetes version to use for the EKS cluster.	string	"1.14"	no
config_output_path	Where to save the Kubectl config file (if write_kubeconfig = true). Assumed to be a directory if the value ends with a forward slash /.	string	"./"	no
create_eks	Controls if EKS resources should be created (it affects almost all resources)	bool	"true"	no
iam_path	If provided, all IAM roles will be created on this path.	string	"/"	no
kubeconfig_aws_authenticator_additional_args	Any additional arguments to pass to the authenticator such as the role to assume. e.g. ["-r", "MyEksRole"].	list(string)	[]	no
kubeconfig_aws_authenticator_command	Command to use to fetch AWS EKS credentials.	string	"aws-iam-authenticator"	no
kubeconfig_aws_authenticator_command_args	Default arguments passed to the authenticator command. Defaults to [token -i $cluster_name].	list(string)	[]	no
kubeconfig_aws_authenticator_env_variables	Environment variables that should be used when executing the authenticator. e.g. { AWS_PROFILE = "eks"}.	map(string)	{}	no
kubeconfig_name	Override the default name used for items kubeconfig.	string	""	no
local_exec_interpreter	Command to run for local-exec resources. Must be a shell-style interpreter. If you are on Windows Git Bash is a good choice.	list(string)	[ "/bin/sh", "-c" ]	no
manage_aws_auth	Whether to apply the aws-auth configmap file.	string	"true"	no
manage_cluster_iam_resources	Whether to let the module manage cluster IAM resources. If set to false, cluster_iam_role_name must be specified.	bool	"true"	no
manage_worker_autoscaling_policy	Whether to let the module manage the cluster autoscaling iam policy.	bool	"true"	no
manage_worker_iam_resources	Whether to let the module manage worker IAM resources. If set to false, iam_instance_profile_name must be specified for workers.	bool	"true"	no
map_accounts	Additional AWS account numbers to add to the aws-auth configmap. See examples/basic/variables.tf for example format.	list(string)	[]	no
map_roles	Additional IAM roles to add to the aws-auth configmap. See examples/basic/variables.tf for example format.	object	[]	no
map_users	Additional IAM users to add to the aws-auth configmap. See examples/basic/variables.tf for example format.	object	[]	no
node_groups	A list of maps defining node group configurations to be defined using AWS EKS Managed Node Groups. See workers_group_defaults for valid keys.	any	[]	no
permissions_boundary	If provided, all IAM roles will be created with this permissions boundary attached.	string	"null"	no
subnets	A list of subnets to place the EKS cluster and workers within.	list(string)	n/a	yes
tags	A map of tags to add to all resources.	map(string)	{}	no
vpc_id	VPC where the cluster and workers will be deployed.	string	n/a	yes
worker_additional_security_group_ids	A list of additional security group ids to attach to worker instances	list(string)	[]	no
worker_ami_name_filter	Name filter for AWS EKS worker AMI. If not provided, the latest official AMI for the specified 'cluster_version' is used.	string	""	no
worker_ami_name_filter_windows	Name filter for AWS EKS Windows worker AMI. If not provided, the latest official AMI for the specified 'cluster_version' is used.	string	""	no
worker_ami_owner_id	The ID of the owner for the AMI to use for the AWS EKS workers. Valid values are an AWS account ID, 'self' (the current account), or an AWS owner alias (e.g. 'amazon', 'aws-marketplace', 'microsoft').	string	"602401143452"	no
worker_ami_owner_id_windows	The ID of the owner for the AMI to use for the AWS EKS Windows workers. Valid values are an AWS account ID, 'self' (the current account), or an AWS owner alias (e.g. 'amazon', 'aws-marketplace', 'microsoft').	string	"801119661308"	no
worker_create_initial_lifecycle_hooks	Whether to create initial lifecycle hooks provided in worker groups.	bool	"false"	no
worker_create_security_group	Whether to create a security group for the workers or attach the workers to worker_security_group_id.	bool	"true"	no
worker_groups	A list of maps defining worker group configurations to be defined using AWS Launch Configurations. See workers_group_defaults for valid keys.	any	[]	no
worker_groups_launch_template	A list of maps defining worker group configurations to be defined using AWS Launch Templates. See workers_group_defaults for valid keys.	any	[]	no
worker_security_group_id	If provided, all workers will be attached to this security group. If not given, a security group will be created with necessary ingress/egress to work with the EKS cluster.	string	""	no
worker_sg_ingress_from_port	Minimum port number from which pods will accept communication. Must be changed to a lower value if some pods in your cluster will expose a port lower than 1025 (e.g. 22, 80, or 443).	number	"1025"	no
workers_additional_policies	Additional policies to be added to workers	list(string)	[]	no
workers_group_defaults	Override default values for target groups. See workers_group_defaults_defaults in local.tf for valid keys.	any	{}	no
workers_role_name	User defined workers role name.	string	""	no
write_kubeconfig	Whether to write a Kubectl config file containing the cluster configuration. Saved to config_output_path.	bool	"true"	no

Outputs

Name	Description
cloudwatch_log_group_name	Name of cloudwatch log group created
cluster_arn	The Amazon Resource Name (ARN) of the cluster.
cluster_certificate_authority_data	Nested attribute containing certificate-authority-data for your cluster. This is the base64 encoded certificate data required to communicate with your cluster.
cluster_endpoint	The endpoint for your EKS Kubernetes API.
cluster_iam_role_arn	IAM role ARN of the EKS cluster.
cluster_iam_role_name	IAM role name of the EKS cluster.
cluster_id	The name/id of the EKS cluster.
cluster_oidc_issuer_url	The URL on the EKS cluster OIDC Issuer
cluster_security_group_id	Security group ID attached to the EKS cluster.
cluster_version	The Kubernetes server version for the EKS cluster.
config_map_aws_auth	A kubernetes configuration to authenticate to this EKS cluster.
kubeconfig	kubectl config file contents for this EKS cluster.
kubeconfig_filename	The filename of the generated kubectl config.
worker_autoscaling_policy_arn	ARN of the worker autoscaling IAM policy if manage_worker_autoscaling_policy = true
worker_autoscaling_policy_name	Name of the worker autoscaling IAM policy if manage_worker_autoscaling_policy = true
worker_iam_instance_profile_arns	default IAM instance profile ARN for EKS worker groups
worker_iam_instance_profile_names	default IAM instance profile name for EKS worker groups
worker_iam_role_arn	default IAM role ARN for EKS worker groups
worker_iam_role_name	default IAM role name for EKS worker groups
worker_security_group_id	Security group ID attached to the EKS workers.
workers_asg_arns	IDs of the autoscaling groups containing workers.
workers_asg_names	Names of the autoscaling groups containing workers.
workers_default_ami_id	ID of the default worker group AMI
workers_launch_template_arns	ARNs of the worker launch templates.
workers_launch_template_ids	IDs of the worker launch templates.
workers_launch_template_latest_versions	Latest versions of the worker launch templates.
workers_user_data	User data of worker groups