Terraform Terragrunt
Hello Everyone
Welcome to CloudAffaire and this is Debjeet.
In the last blog post, we have discussed terraform refresh.
https://cloudaffaire.com/terraform-refresh/
In this blog post, we will discuss terraform terragrunt.
What is terraform terragrunt?
Terragrunt is a thin wrapper for Terraform that provides extra tools for keeping your Terraform configurations DRY, working with multiple Terraform modules, and managing remote state. Terragrunt supports all terraform commands with additional features. To get more details on terragrunt, please refer below terragrunt documentation.
https://github.com/gruntwork-io/terragrunt
Next, we are going to explain terraform terragrunt with a demo.
Directory structure:
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## Directory structure . ├── module │ ├── subnet │ │ ├── main.tf │ │ ├── outputs.tf │ │ └── variables.tf │ └── vpc │ ├── main.tf │ ├── outputs.tf │ └── variables.tf ├── project │ ├── dev │ │ ├── subnet │ │ │ └── terraform.tfvars │ │ └── vpc │ │ └── terraform.tfvars │ ├── prod │ │ ├── subnet │ │ │ └── terraform.tfvars │ │ └── vpc │ │ └── terraform.tfvars │ └── test │ ├── subnet │ │ └── terraform.tfvars │ └── vpc │ └── terraform.tfvars └── terraform_backend ├── main.tf └── terraform.tfstate |
Terraform terragrunt:
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##--------------------------- ## Terraform: Terragrunt ## ##--------------------------- ###################### ##install terragrunt## ###################### cd wget https://github.com/gruntwork-io/terragrunt/releases/download/v0.18.5/terragrunt_linux_386 mv terragrunt_linux_386 /usr/local/bin/terragrunt chmod +x /usr/local/bin/terragrunt terragrunt ########################################################### ##Configure terraform backend for remote state management## ########################################################### ## Create a directory and get inside it mkdir -p terraform/terraform_backend && cd terraform/terraform_backend ## Create backend resources vi main.tf ------------------ #creates a S3 bucket and a dynamoDB table provider "aws" { region = "ap-south-1" shared_credentials_file = "/home/ec2-user/.aws/credentials" profile = "default" } resource "aws_s3_bucket" "mys3bucket" { bucket = "my-s3-terraform-backend-cloudaffaire" #needs to be unique across AWS force_destroy = true tags { Name = "S3 bucket for terraform backend state storage" } } resource "aws_dynamodb_table" "mydynamodbtable" { name = "my-dynamodb-terraform-backend-cloudaffaire" hash_key = "LockID" read_capacity = 5 write_capacity = 5 attribute { name = "LockID" type = "S" } tags { Name = "dynamoDB table for terraform backend state locking" } } ------------------ :wq ## Format code terraform fmt ## Initialize terraform terraform init ## Create the resource terraform apply ## Move to your home directory cd ################## ##create modules## ################## ##module: vpc## ## Create directory for module mkdir -p terraform/module/vpc && mkdir -p terraform/module/subnet ## Vpc module resource vi terraform/module/vpc/main.tf --------------------------- locals { tag = "${var.name}_${var.env}_${var.version}_${var.tag}" } provider "aws" { region = "${var.aws_region}" shared_credentials_file = "${var.shared_credentials_file}" profile = "${var.profile}" } terraform { backend "s3" {} } resource "aws_vpc" "myvpc" { cidr_block = "${var.vpc_cidr}" tags { Name = "${local.tag}" } } --------------------------- :wq ## Vpc module variables vi terraform/module/vpc/variables.tf --------------------------- variable "aws_region" { description = "AWS region where the VPC will be created" default = "ap-south-1" } variable "shared_credentials_file" { description = "credential file to be used to connect to AWS" default = "/home/ec2-user/.aws/credentials" } variable "profile" { description = "profile name of the credentials" default = "default" } variable "vpc_cidr" { description = "CIDR block of VPC" default = "192.168.0.0/16" } variable "name" { description = "name to be used on all the resources as identifier" default = "" } variable "env" { description = "application environment" default = "" } variable "tag" { description = "tag for vpc" default = "" } variable "version" { description = "application version" default = "" } --------------------------- :wq ## Vpc module output vi terraform/module/vpc/outputs.tf --------------------------- output "vpc_id" { description = "The ID of the VPC" value = "${aws_vpc.myvpc.id}" } --------------------------- :wq ##module: subnet## ## Subnet module resource vi terraform/module/subnet/main.tf --------------------------- locals { tag = "${var.name}_${var.env}_${var.version}_${var.tag}" } provider "aws" { region = "${var.aws_region}" shared_credentials_file = "${var.shared_credentials_file}" profile = "${var.profile}" } terraform { backend "s3" {} } data "terraform_remote_state" "vpc" { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "${var.name}/${var.env}/${var.version}/vpc/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } resource "aws_subnet" "myvpc_subnet" { vpc_id = "${data.terraform_remote_state.vpc.vpc_id}" cidr_block = "${var.subnet_cidr}" availability_zone = "${var.subnet_availability_zone}" tags { Name = "${local.tag}" } } --------------------------- :wq ## Subnet module variables vi terraform/module/subnet/variables.tf --------------------------- variable "aws_region" { description = "AWS region where the VPC will be created" default = "ap-south-1" } variable "shared_credentials_file" { description = "credential file to be used to connect to AWS" default = "/home/ec2-user/.aws/credentials" } variable "profile" { description = "profile name of the credentials" default = "default" } variable "vpc_id" { description = "VPC ID" default = "" } variable "subnet_cidr" { description = "CIDR block for the subnet" default = "" } variable "subnet_availability_zone" { description = "Availability zone of the subnet" default = "" } variable "name" { description = "name to be used on all the resources as identifier" default = "" } variable "env" { description = "application environment" default = "" } variable "tag" { description = "tag for subnet" default = "" } variable "version" { description = "application version" default = "" } --------------------------- :wq ## Subnet module output vi terraform/module/subnet/outputs.tf --------------------------- output "subnet_id" { description = "Subnet ID" value = "${aws_subnet.myvpc_subnet.id}" } --------------------------- :wq ## Format code terraform fmt ################################### ##github configuration for module## ################################### ## login to github and create a repository named terragrunt ## Copy the repository ssh link ## git@github.com:CloudAffaire/terragrunt.git ## Configure github for ssh ssh-keygen -t rsa -C "cloudaffaire@gmail.com" ## Upload module vpc and subnet to github terragrunt repository cd terraform/module && git init git config --local user.name "debjeet" && \ git config --local user.email "debjeet@cloudaffaire.com" git add . git commit -m "initial commit" git remote add origin git@github.com:CloudAffaire/terragrunt.git git push -u origin master git tag -a v1.0 -m "myapp version 1.0" git push origin v1.0 cd #git push --delete origin v1.0 #git tag --delete v1.0 ################### ##create projects## ################### ##project:prod## ## Create project directory for production mkdir -p terraform/project/prod/vpc/ && mkdir -p terraform/project/prod/subnet/ ## Create terraform.tfvars for prod environment of vpc module vi terraform/project/prod/vpc/terraform.tfvars -------------------------------------------- terragrunt = { remote_state { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "myapp/prod/v1/vpc/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } terraform { source = "git::git@github.com:CloudAffaire/terragrunt.git//vpc?ref=v1.0" } } vpc_cidr = "10.0.0.0/16" aws_region = "ap-south-1" name = "myapp" env = "prod" tag = "vpc" version = "v1" -------------------------------------------- :wq ## Create terraform.tfvars for prod environment of subnet module vi terraform/project/prod/subnet/terraform.tfvars -------------------------------------------- terragrunt = { remote_state { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "myapp/prod/v1/subnet/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } terraform { source = "git::git@github.com:CloudAffaire/terragrunt.git//subnet?ref=v1.0" } } subnet_cidr = "10.0.0.0/24" aws_region = "ap-south-1" name = "myapp" env = "prod" tag = "subnet" version = "v1" -------------------------------------------- :wq ## Create prod resources using terragrunt cd terraform/project/prod/vpc/ terragrunt plan terragrunt apply cd ../subnet terragrunt plan terragrunt apply cd ##Project:dev## ## Create project directory for development mkdir -p terraform/project/dev/vpc/ && mkdir -p terraform/project/dev/subnet/ ## Create terraform.tfvars for dev environment of vpc module vi terraform/project/dev/vpc/terraform.tfvars -------------------------------------------- terragrunt = { remote_state { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "myapp/dev/v1/vpc/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } terraform { source = "git::git@github.com:CloudAffaire/terragrunt.git//vpc?ref=v1.0" } } vpc_cidr = "10.0.0.0/16" aws_region = "ap-south-1" name = "myapp" env = "dev" tag = "vpc" version = "v1" -------------------------------------------- :wq ## Create terraform.tfvars for dev environment of subnet module vi terraform/project/dev/subnet/terraform.tfvars -------------------------------------------- terragrunt = { remote_state { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "myapp/dev/v1/subnet/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } terraform { source = "git::git@github.com:CloudAffaire/terragrunt.git//subnet?ref=v1.0" } } subnet_cidr = "10.0.0.0/24" aws_region = "ap-south-1" name = "myapp" env = "dev" tag = "subnet" version = "v1" -------------------------------------------- :wq ## Create dev resources using terragrunt cd terraform/project/dev/vpc/ terragrunt plan terragrunt apply cd ../subnet terragrunt plan terragrunt apply cd ##Project:test## ## Create project directory for testing mkdir -p terraform/project/test/vpc/ && mkdir -p terraform/project/test/subnet/ ## Create terraform.tfvars for test environment of vpc module vi terraform/project/test/vpc/terraform.tfvars -------------------------------------------- terragrunt = { remote_state { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "myapp/test/v1/vpc/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } terraform { source = "git::git@github.com:CloudAffaire/terragrunt.git//vpc?ref=v1.0" } } vpc_cidr = "10.0.0.0/16" aws_region = "ap-south-1" name = "myapp" env = "test" tag = "vpc" version = "v1" -------------------------------------------- :wq ## Create terraform.tfvars for test environment of subnet module vi terraform/project/test/subnet/terraform.tfvars -------------------------------------------- terragrunt = { remote_state { backend = "s3" config { bucket = "my-s3-terraform-backend-cloudaffaire" key = "myapp/test/v1/subnet/terraform.tfstate" region = "ap-south-1" dynamodb_table = "my-dynamodb-terraform-backend-cloudaffaire" } } terraform { source = "git::git@github.com:CloudAffaire/terragrunt.git//subnet?ref=v1.0" } } subnet_cidr = "10.0.0.0/24" aws_region = "ap-south-1" name = "myapp" env = "test" tag = "subnet" version = "v1" -------------------------------------------- :wq ## Create test resources using terragrunt cd terraform/project/test/vpc/ terragrunt plan terragrunt apply cd ../subnet terragrunt plan terragrunt apply cd ## cleanup ## cd terraform/project/prod/subnet/ terragrunt destroy cd ../vpc terragrunt destroy cd ../../dev/subnet/ terragrunt destroy cd ../vpc terragrunt destroy cd ../../test/subnet/ terragrunt destroy cd ../vpc terragrunt destroy cd ../../../terraform_backend/ terraform destroy cd && rm -rf terraform #login to github and delete terragrunt repository |
Hope you have enjoyed this article. With this, we are concluding our introductory series on terraform.
To get more details on terragrunt, please refer below terragrunt documentation.
https://github.com/gruntwork-io/terragrunt
To get more details on terraform, please refer below terraform documentation.
https://www.terraform.io/docs/index.html