/terraform-aws-eks

A Terraform module to create an Elastic Kubernetes (EKS) cluster and associated worker instances on AWS.

Primary LanguageHCLApache License 2.0Apache-2.0

terraform-aws-eks

Lint Status LICENSE

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.

Important note

The cluster_version is the required variable. Kubernetes is evolving a lot, and each major version includes new features, fixes, or changes.

Always check Kubernetes Release Notes before updating the major version.

You also need to ensure your applications and add ons are updated, or workloads could fail after the upgrade is complete. For action, you may need to take before upgrading, see the steps in the EKS documentation.

An example of harming update was the removal of several commonly used, but deprecated APIs, in Kubernetes 1.16. More information on the API removals, see the Kubernetes blog post.

By default, this module manages the aws-auth configmap for you (manage_aws_auth=true). To avoid the following issue where the EKS creation is ACTIVE but not ready. We implemented a "retry" logic with a fork of the http provider https://github.com/terraform-aws-modules/terraform-provider-http. This fork adds the support of a self-signed CA certificate. The original PR can be found at hashicorp/terraform-provider-http#29.

Setting instance_refresh_enabled to true will recreate your worker nodes without draining them first. It is recommended to install aws-node-termination-handler for proper node draining. Find the complete example here instance_refresh.

Usage example

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

data "aws_eks_cluster" "cluster" {
  name = module.my-cluster.cluster_id
}

data "aws_eks_cluster_auth" "cluster" {
  name = module.my-cluster.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 = "1.17"
  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, [""]), 0)
  cluster_ca_certificate = base64decode(element(concat(data.aws_eks_cluster.cluster[*].certificate_authority.0.data, [""]), 0))
  token                  = element(concat(data.aws_eks_cluster_auth.cluster[*].token, [""]), 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

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

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

Apache 2 Licensed. See LICENSE for full details.

Requirements

Name Version
terraform >= 0.13.1
aws >= 3.40.0
http >= 2.4.1
kubernetes >= 1.11.1
local >= 1.4

Providers

Name Version
aws >= 3.40.0
http >= 2.4.1
kubernetes >= 1.11.1
local >= 1.4

Modules

Name Source Version
fargate ./modules/fargate
node_groups ./modules/node_groups

Resources

Name Type
aws_autoscaling_group.workers resource
aws_autoscaling_group.workers_launch_template resource
aws_cloudwatch_log_group.this resource
aws_eks_cluster.this resource
aws_iam_instance_profile.workers resource
aws_iam_instance_profile.workers_launch_template resource
aws_iam_openid_connect_provider.oidc_provider resource
aws_iam_policy.cluster_elb_sl_role_creation resource
aws_iam_role.cluster resource
aws_iam_role.workers resource
aws_iam_role_policy_attachment.cluster_AmazonEKSClusterPolicy resource
aws_iam_role_policy_attachment.cluster_AmazonEKSServicePolicy resource
aws_iam_role_policy_attachment.cluster_AmazonEKSVPCResourceControllerPolicy resource
aws_iam_role_policy_attachment.cluster_elb_sl_role_creation resource
aws_iam_role_policy_attachment.workers_AmazonEC2ContainerRegistryReadOnly resource
aws_iam_role_policy_attachment.workers_AmazonEKSWorkerNodePolicy resource
aws_iam_role_policy_attachment.workers_AmazonEKS_CNI_Policy resource
aws_iam_role_policy_attachment.workers_additional_policies resource
aws_launch_configuration.workers resource
aws_launch_template.workers_launch_template resource
aws_security_group.cluster resource
aws_security_group.workers resource
aws_security_group_rule.cluster_egress_internet resource
aws_security_group_rule.cluster_https_worker_ingress resource
aws_security_group_rule.cluster_primary_ingress_workers resource
aws_security_group_rule.cluster_private_access_cidrs_source resource
aws_security_group_rule.cluster_private_access_sg_source resource
aws_security_group_rule.workers_egress_internet resource
aws_security_group_rule.workers_ingress_cluster resource
aws_security_group_rule.workers_ingress_cluster_https resource
aws_security_group_rule.workers_ingress_cluster_kubelet resource
aws_security_group_rule.workers_ingress_cluster_primary resource
aws_security_group_rule.workers_ingress_self resource
kubernetes_config_map.aws_auth resource
local_file.kubeconfig resource
aws_ami.eks_worker data source
aws_ami.eks_worker_windows data source
aws_caller_identity.current data source
aws_iam_instance_profile.custom_worker_group_iam_instance_profile data source
aws_iam_instance_profile.custom_worker_group_launch_template_iam_instance_profile data source
aws_iam_policy_document.cluster_assume_role_policy data source
aws_iam_policy_document.cluster_elb_sl_role_creation data source
aws_iam_policy_document.workers_assume_role_policy data source
aws_iam_role.custom_cluster_iam_role data source
aws_partition.current data source
http_http.wait_for_cluster data source

Inputs

Name Description Type Default Required
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
aws_auth_additional_labels Additional kubernetes labels applied on aws-auth ConfigMap map(string) {} no
cluster_create_endpoint_private_access_sg_rule Whether to create security group rules for the access to the Amazon EKS private API server endpoint. When is true, cluster_endpoint_private_access_cidrs must be setted. bool false 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 "30m" no
cluster_delete_timeout Timeout value when deleting the EKS cluster. string "15m" no
cluster_egress_cidrs List of CIDR blocks that are permitted for cluster egress traffic. list(string) 
[
  "0.0.0.0/0"
]
 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_encryption_config Configuration block with encryption configuration for the cluster. See examples/secrets_encryption/main.tf for example format 
list(object({
    provider_key_arn = string
    resources        = 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_private_access_cidrs List of CIDR blocks which can access the Amazon EKS private API server endpoint. To use this cluster_endpoint_private_access and cluster_create_endpoint_private_access_sg_rule must be set to true. list(string) null no
cluster_endpoint_private_access_sg List of security group IDs which can access the Amazon EKS private API server endpoint. To use this cluster_endpoint_private_access and cluster_create_endpoint_private_access_sg_rule must be set to true. list(string) null no
cluster_endpoint_public_access Indicates whether or not the Amazon EKS public API server endpoint is enabled. When it's set to false ensure to have a proper private access with cluster_endpoint_private_access = true. bool true no
cluster_endpoint_public_access_cidrs List of CIDR blocks which can access the Amazon EKS public API server endpoint. list(string) 
[
  "0.0.0.0/0"
]
 no
cluster_iam_role_name IAM role name for the cluster. If manage_cluster_iam_resources is set to false, set this to reuse an existing IAM role. If manage_cluster_iam_resources is set to true, set this to force the created role name. 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_service_ipv4_cidr service ipv4 cidr for the kubernetes cluster string null no
cluster_version Kubernetes version to use for the EKS cluster. string n/a yes
create_eks Controls if EKS resources should be created (it affects almost all resources) bool true no
create_fargate_pod_execution_role Controls if the EKS Fargate pod execution IAM role should be created. bool true no
eks_oidc_root_ca_thumbprint Thumbprint of Root CA for EKS OIDC, Valid until 2037 string "9e99a48a9960b14926bb7f3b02e22da2b0ab7280" no
enable_irsa Whether to create OpenID Connect Provider for EKS to enable IRSA bool false no
fargate_pod_execution_role_name The IAM Role that provides permissions for the EKS Fargate Profile. string null no
fargate_profiles Fargate profiles to create. See fargate_profile keys section in fargate submodule's README.md for more details any {} 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_file_permission File permission of the Kubectl config file containing cluster configuration saved to kubeconfig_output_path. string "0600" no
kubeconfig_name Override the default name used for items kubeconfig. string "" no
kubeconfig_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
manage_aws_auth Whether to apply the aws-auth configmap file. bool 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_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. 
list(object({
    rolearn  = string
    username = string
    groups   = list(string)
  }))
 [] no
map_users Additional IAM users to add to the aws-auth configmap. See examples/basic/variables.tf for example format. 
list(object({
    userarn  = string
    username = string
    groups   = list(string)
  }))
 [] no
node_groups Map of map of node groups to create. See node_groups module's documentation for more details any {} no
node_groups_defaults Map of values to be applied to all node groups. See node_groups module's documentation for more details 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. Tags added to launch configuration or templates override these values for ASG Tags only. map(string) {} no
vpc_id VPC where the cluster and workers will be deployed. string n/a yes
wait_for_cluster_timeout Allows for a configurable timeout (in seconds) when waiting for a cluster to come up number 300 no
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 "amazon" 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 "amazon" no
worker_create_cluster_primary_security_group_rules Whether to create security group rules to allow communication between pods on workers and pods using the primary cluster security group. bool false 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_egress_cidrs List of CIDR blocks that are permitted for workers egress traffic. list(string) 
[
  "0.0.0.0/0"
]
 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 kubeconfig_output_path. bool true no

Outputs

Name Description
cloudwatch_log_group_arn Arn of cloudwatch log group created
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. Will block on cluster creation until the cluster is really ready.
cluster_oidc_issuer_url The URL on the EKS cluster OIDC Issuer
cluster_primary_security_group_id The cluster primary security group ID created by the EKS cluster on 1.14 or later. Referred to as 'Cluster security group' in the EKS console.
cluster_security_group_id Security group ID attached to the EKS cluster. On 1.14 or later, this is the 'Additional security groups' in the EKS console.
cluster_version The Kubernetes server version for the EKS cluster.
config_map_aws_auth A kubernetes configuration to authenticate to this EKS cluster.
fargate_iam_role_arn IAM role ARN for EKS Fargate pods
fargate_iam_role_name IAM role name for EKS Fargate pods
fargate_profile_arns Amazon Resource Name (ARN) of the EKS Fargate Profiles.
fargate_profile_ids EKS Cluster name and EKS Fargate Profile names separated by a colon (:).
kubeconfig kubectl config file contents for this EKS cluster. Will block on cluster creation until the cluster is really ready.
kubeconfig_filename The filename of the generated kubectl config. Will block on cluster creation until the cluster is really ready.
node_groups Outputs from EKS node groups. Map of maps, keyed by var.node_groups keys
oidc_provider_arn The ARN of the OIDC Provider if enable_irsa = true.
security_group_rule_cluster_https_worker_ingress Security group rule responsible for allowing pods to communicate with the EKS cluster API.
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_default_ami_id_windows ID of the default Windows 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