env

Terraform Modules Folder

All the module calls made from this folder from dev.tf file.

• This folder contains following files
  • dev.tf (modules file )
  • backend.tf ( contains backend configuration of the terraform, which contains terraform state files).
  • outputs.tf ( output's of the resource attributes after terraform apply)
  • version.tf ( contains terraform version and cloud provider version)
  • variables.tf (all the variable which required by the terraform modules.)

What is a module?

A Terraform Module is a canonical, reusable, best-practices definition for how to run a single piece of infrastructure, such as a database or server cluster. Each Module is written using a combination of Terraform and scripts (mostly bash) and include automated tests, documentation, and examples.

• Every module has:
  • Input variables: to accept values from the calling module.
  • Output values: to return results to the calling module, which it can then use to populate arguments elsewhere.
  • Resources: to define one or more infrastructure objects that the module will manage.
  • Source: A source can be any local folder path or remote module located in source control systems like git.

EKS cluster example module

Usage: The following module call will create EKS cluster and cluster node pool resources. Resources will be configured by using the following input variables on this module.

# Create Elastic Kubernetes Service
module "eks" {
  source                = "../modules/eks"
  name                  = local.name_prefix
  region                = var.region
  environment           = var.environment
  desired_capacity      = var.desired_capacity
  max_size              = var.max_size
  min_size              = var.min_size
  instance_type         = var.instance_type
  role_arn              = module.iam.role_arn
  worker_role_arn       = module.iam.worker_role_arn
  subnet_ids            = module.vpc.aws_subnet_private_ids
  security_group_id     = module.vpc.security_group_id
  public_subnets        = module.vpc.aws_subnet_public_ids
  instance_profile_name = module.iam.iam_instance_profile
  tags                  = local.tags
}

IAM example module

Usage: The following module call will create IAM resources. Resources will be configured using the following input variables on this modules.

# Create Identity Access Management
module "iam" {
  source      = "../modules/iam"
  name        = local.name_prefix
  region      = var.region
  environment = var.environment
  tags        = local.tags
}

vpc example module

Usage: The following module call will create AWS virtual private network(VPC), subnets, firewall rules, security groups, NAT Gateway's, Internet Gateway, Elastic IP's, route tables, route table associations.

# Create Virtual Private Cloud
module "vpc" {
  source             = "../modules/vpc"
  name               = local.name_prefix
  environment        = var.environment
  region             = var.region
  public_cidr_block  = var.public_cidr_block
  private_cidr_block = var.private_cidr_block
  tags               = local.tags
}

s3 example module

Usage: The following module call will create Amazon s3 bucket. Resources will be configured using following input variables on this module.

# Create S3 bucket
module "s3" {
  source      = "../modules/s3"
  name        = local.name_prefix
  environment = var.environment
  tags        = local.tags
}

Requirements

Name	Version
terraform	>= 0.12
aws	~> 3.0

Providers

Name	Version
aws	~> 3.0

Modules

Name	Source	Version
eks	../modules/eks
iam	../modules/iam
s3	../modules/s3
vpc	../modules/vpc

Resources

Name	Type
aws_caller_identity.current	data source

Inputs

Name	Description	Type	Default	Required
desired_capacity	Desired capacity for the auto scaling Group.	number	"3"	no
environment	Name of the environment where infrastructure is being built.	string	n/a	yes
instance_type	Type of instance to be used for the Kubernetes cluster.	string	"r5d.2xlarge"	no
max_size	Maximum number of the instances in autoscaling group	number	"5"	no
min_size	Minimum number of the instances in autoscaling group	nunmber	"3"	no
name	Name is the prefix to use for resources that needs to be created.	string	n/a	yes
private_cidr_block	List of private subnet cidr blocks	list(string)	[ "10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24" ]	no
public_cidr_block	List of public subnet cidr blocks	list(string)	[ "10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24" ]	no
region	The AWS region where terraform builds resources.	string	"us-east-1"	no
resource_owner	The name of the Project Owner	string	"Datastax"	no

Outputs

Name	Description
bucket_id	Bucket Name (aka ID)
cluster_Endpoint	The endpoint for your EKS Kubernetes API
cluster_name	Name of the EKS cluster
cluster_version	Version of the EKS cluster