• Terraform https://www.terraform.io
• Docker https://www.docker.com/
• AWS Codepipeline https://aws.amazon.com/codepipeline/

Install terraform using the this link https://learn.hashicorp.com/terraform/getting-started/install.html

Generate a new personal github token following the steps from this link

Paste the token genrated in modules/copepipeline/main.tf at the following line Also add owner for the repository you want to deploy along with repository namd and branch. AWS code build created using terraform will read the repository owner, name, brnach from the following to run AWS code build using this source.

configuration = {
        Owner      = "owner_of_repo"
        Repo       = "repo_name"
        Branch     = "branch_of_repo"
        OAuthToken = "***********token*********"
      }

In deploy.tf set access_key and secret_key for AWS account.

provider "aws" {
  region = var.region
  access_key = "**********************"
  secret_key = "**********************"
}

In application root folder create .tfvars file for staging, production, testing environment. Define all variables in variables.tf file and specify value for each variable in .tfvars file for each environment.

For example, in variables.tf file define variables as follows

variable "region" {
  description = "Region that the instances will be created"
}

/*====
environment specific variables
======*/

variable "database_name" {
  description = "The database name for Production"
}

variable "database_username" {
  description = "The username for the Production database"
}

variable "database_password" {
  description = "The user password for the Production database"
}

variable "secret_key_base" {
  description = "The Rails secret key for production"
}

variable "domain" {
  default = "The domain of your application"
}

variable "rabbit_name" {
	description = "A random environment"
}

variable "environment" {
	description = "Environment for the application"
}

variable "availability_zones" {
	type = "list"
}

And in production.tfvars or staging.tfvars the value for each variable can be set. For example in production.tfvars

region                        = "us-east-1"
domain                        = "railsterraform.com"

/* rds */
database_name      = "railsterraform_production"
database_username  = "railsterraform"
database_password  = "myawesomepasswordproduction"

/* secret key */
secret_key_base    = "8d412aee3ceaa494fe1c276f5f7e524b9e33f649c03690e689e5b36a0cf4ce2a6f50024bc31f276c22b668e619d61a42b79f5e595759f377a8fa373e2907f41e"

rabbit_name = "Yo Yo Singh"
environment = "production"

availability_zones = ["us-east-1a", "us-east-1b"]

After this setup run the following command in project root $ terraform init

After successfully installing the terraform plugins run the plan command. When running the plan command pass --var-file argument to command with value of the .tfvars file you want to run for. For example to deploy the application to staging environment run the following command

$ terraform plan --var-file=staging.tfvars

After successfully creating the plan run the following command

$ terraform apply --var-file=staging.tfvars

This will start creating your AWS infrastructure for the application and will success with providing url for the application loadbalancer using the following command

$ terraform output alb_dns_name