├── .gitignore ├── globals.tfvars ├── dev.tfvars ├── prd.tfvars ├── uat.tfvars ├── output.tf ├── providers.tf ├── globals.tf ├── vpc.tf ├── variables.tf ├── computing.tf ├── docker-compose.yaml ├── README.md └── LICENSE /.gitignore: -------------------------------------------------------------------------------- 1 | .terraform.lock.hcl 2 | .terraform/ 3 | terraform.tfstate.d/ 4 | -------------------------------------------------------------------------------- /globals.tfvars: -------------------------------------------------------------------------------- 1 | aws_region = "eu-central-1" 2 | project_id = "1a2b3c4d5e6f" 3 | project_name = "Internal project name" 4 | ami_ubuntu_server_2004 = "ubuntu/images/hvm-ssd/ubuntu-trusty-14.04-amd64-server-20170727" 5 | -------------------------------------------------------------------------------- /dev.tfvars: -------------------------------------------------------------------------------- 1 | env_name = "development" 2 | env_prefix = "dev" 3 | 4 | # network definitions 5 | vpc_cidr_block = "172.16.0.0/16" 6 | subnet_cidr_block = "172.16.10.0/24" 7 | 8 | # ec2 definitions 9 | small_instance = "t2.micro" 10 | -------------------------------------------------------------------------------- /prd.tfvars: -------------------------------------------------------------------------------- 1 | env_name = "production" 2 | env_prefix = "prd" 3 | 4 | # network definitions 5 | vpc_cidr_block = "172.14.0.0/16" 6 | subnet_cidr_block = "172.14.10.0/24" 7 | 8 | # ec2 definitions 9 | small_instance = "t2.small" 10 | -------------------------------------------------------------------------------- /uat.tfvars: -------------------------------------------------------------------------------- 1 | env_name = "user-acceptance-test" 2 | env_prefix = "uat" 3 | 4 | # network definitions 5 | vpc_cidr_block = "172.15.0.0/16" 6 | subnet_cidr_block = "172.15.10.0/24" 7 | 8 | # ec2 definitions 9 | small_instance = "t2.micro" 10 | -------------------------------------------------------------------------------- /output.tf: -------------------------------------------------------------------------------- 1 | output "environment" { 2 | description = "Current environment" 3 | #value = terraform.workspace 4 | value = var.env_prefix 5 | } 6 | 7 | output "region" { 8 | description = "AWS Region" 9 | value = var.aws_region 10 | } 11 | -------------------------------------------------------------------------------- /providers.tf: -------------------------------------------------------------------------------- 1 | terraform { 2 | required_providers { 3 | aws = { 4 | source = "hashicorp/aws" 5 | version = "5.84.0" 6 | } 7 | } 8 | } 9 | 10 | provider "aws" { 11 | profile = terraform.workspace 12 | skip_credentials_validation = true 13 | skip_metadata_api_check = true 14 | skip_requesting_account_id = true 15 | } 16 | -------------------------------------------------------------------------------- /globals.tf: -------------------------------------------------------------------------------- 1 | variable "aws_region" { 2 | description = "AWS region" 3 | type = string 4 | } 5 | 6 | variable "project_id" { 7 | description = "Project ID" 8 | type = string 9 | } 10 | 11 | variable "project_name" { 12 | description = "Project name" 13 | type = string 14 | } 15 | 16 | variable "ami_ubuntu_server_2004" { 17 | description = "AMI for Ubuntu Server 20.04" 18 | type = string 19 | } 20 | 21 | -------------------------------------------------------------------------------- /vpc.tf: -------------------------------------------------------------------------------- 1 | resource "aws_vpc" "main" { 2 | cidr_block = var.vpc_cidr_block 3 | instance_tenancy = "default" 4 | 5 | tags = { 6 | Environment = var.env_name 7 | Project_ID = var.project_id 8 | Project_Name = var.project_name 9 | } 10 | } 11 | 12 | resource "aws_subnet" "example" { 13 | vpc_id = aws_vpc.main.id 14 | cidr_block = var.subnet_cidr_block 15 | 16 | tags = { 17 | Environment = var.env_name 18 | Project_ID = var.project_id 19 | Project_Name = var.project_name 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /variables.tf: -------------------------------------------------------------------------------- 1 | # Global definitions 2 | 3 | variable "env_name" { 4 | type = string 5 | description = "Environment full name" 6 | } 7 | 8 | variable "env_prefix" { 9 | type = string 10 | description = "Environment name prefix" 11 | } 12 | 13 | variable "vpc_cidr_block" { 14 | type = string 15 | description = "The IPv4 CIDR block for the VPC" 16 | } 17 | 18 | variable "subnet_cidr_block" { 19 | type = string 20 | description = "The IPv4 CIDR block for the subnet" 21 | } 22 | 23 | variable "small_instance" { 24 | type = string 25 | description = "EC2 small instance." 26 | } 27 | -------------------------------------------------------------------------------- /computing.tf: -------------------------------------------------------------------------------- 1 | data "aws_ami" "ubuntu" { 2 | most_recent = true 3 | 4 | filter { 5 | name = "name" 6 | values = [var.ami_ubuntu_server_2004] 7 | } 8 | 9 | filter { 10 | name = "virtualization-type" 11 | values = ["hvm"] 12 | } 13 | 14 | owners = ["099720109477"] # Canonical 15 | } 16 | 17 | resource "aws_instance" "example" { 18 | ami = data.aws_ami.ubuntu.id 19 | instance_type = var.small_instance 20 | subnet_id = aws_subnet.example.id 21 | 22 | cpu_options { 23 | core_count = 2 24 | threads_per_core = 2 25 | } 26 | 27 | tags = { 28 | Name = "tf-example" 29 | } 30 | } 31 | -------------------------------------------------------------------------------- /docker-compose.yaml: -------------------------------------------------------------------------------- 1 | services: 2 | localstack-dev: 3 | container_name: "${LOCALSTACK_DOCKER_NAME:-localstack-dev}" 4 | image: localstack/localstack 5 | ports: 6 | - "127.0.0.1:4566:4566" 7 | - "127.0.0.1:4510-4559:4510-4559" 8 | volumes: 9 | - "${LOCALSTACK_VOLUME_DIR:-./volume-dev}:/var/lib/localstack" 10 | - "/var/run/docker.sock:/var/run/docker.sock" 11 | localstack-uat: 12 | container_name: "${LOCALSTACK_DOCKER_NAME:-localstack-uat}" 13 | image: localstack/localstack 14 | ports: 15 | - "127.0.0.1:4567:4566" 16 | - "127.0.0.1:4610-4659:4510-4559" 17 | volumes: 18 | - "${LOCALSTACK_VOLUME_DIR:-./volume-uat}:/var/lib/localstack" 19 | - "/var/run/docker.sock:/var/run/docker.sock" 20 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Terraform Workspace for AWS multi account architectures. 2 | 3 | ## Abstract 4 | 5 | This is a example on how to build and manage an AWS multi account architecture using Terraform workspaces. The proposal focus only in segment and relate an account to a workspace. 6 | 7 | ### Disclaimer 8 | 9 | There wasn't aim to modularize, treat security issues or save the state on a remote backend, just present a proposal for multi-account issue. 10 | 11 | ## Requirements 12 | 13 | - [Terraform](https://developer.hashicorp.com/terraform/install) or [OpenTofu](https://opentofu.org/docs/intro/install/) 14 | - [AWS cli](https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html) 15 | 16 | There is a way to test it in local environment before applying to an AWS infrastructure using [Localstack](https://www.localstack.cloud/). 17 | 18 | As OpenTofu is an opensource alternative to Terraform, I will use it. To know more about Terraform licensing, check [here](https://www.hashicorp.com/blog/hashicorp-updates-licensing-faq-based-on-community-questions). 19 | 20 | This example uses the Docker Compose solution to run Localstack. Neverthless there is other ways to run it, jus check the [official documentation](https://docs.localstack.cloud/getting-started/installation/) for alternatives. 21 | 22 | - [Docker](https://docs.docker.com/engine/install/) 23 | - [Docker compose](https://docs.docker.com/compose/install/) 24 | 25 | ## Setup 26 | 27 | All the documentation was written running on Localstack, but it was tested on multiple accounts as well. Just adjust your **~/.aws/config** and **~/.aws/credentials** files with your credentials and it should work. 28 | 29 | ### The Localstack service 30 | 31 | There is a docker-compose.yaml file in repository ready to use, with 2 instances of the Localstack running in different ports. It was selected this approach for simplicity, to isolate the accounts and simulate different environments. The instances were named as **localstack-dev** and **localstack-uat**. 32 | 33 | To put up the services just run `docker-compose up -d --build`. 34 | 35 | ### The AWS config files 36 | 37 | Adjust your **~/.aws/config** file to have 2 profiles (accounts) as defined in Localstack instances. 38 | 39 | PS. May be a good idea to backup the file before change it. ;-) 40 | 41 | ``` 42 | [profile dev] 43 | region=us-east-1 44 | output=json 45 | endpoint_url = http://localhost:4566 46 | 47 | [profile uat] 48 | region=us-east-1 49 | output=json 50 | endpoint_url = http://localhost:4567 51 | ``` 52 | 53 | Then do the same for the **~/.aws/credentials**. The keys are not important for the test, because we are not testing the auth features (the validation was disabled on Terraform code). 54 | 55 | Remember of the backup :-) 56 | 57 | ``` 58 | [dev] 59 | aws_access_key_id=test 60 | aws_secret_access_key=test 61 | 62 | [uat] 63 | aws_access_key_id=test 64 | aws_secret_access_key=test 65 | ``` 66 | At this point you may be able to run aws cli commands to test the Localstack service. 67 | 68 | ## Provisioning with Terraform 69 | 70 | ### Workspaces 71 | 72 | Terraform uses the default workspace (named as default) when you init a project. As this example uses two accounts associated with environments, we will create 2 workspaces with names **dev** (development) and **uat** (user acceptance test). 73 | 74 | To create a new workspace run the follwing code `opentofu workspace new `. When you create a workspace Terraform automatically make it active. You can check it with `opentofu workspace list`. 75 | 76 | To change between workspaces run `opentofu workspace select `. 77 | 78 | ### Providers 79 | 80 | When defining the providers, the AWS in this case, we need to set the profile, that we dinamically retrieve from the `terraform.workspace` runtime variable. This is the way we associate workspaces to environment (the trick is here). As said before, for simplicity we will skip all the auth validations. 81 | 82 | ``` 83 | provider "aws" { 84 | profile = terraform.workspace 85 | skip_credentials_validation = true 86 | skip_metadata_api_check = true 87 | skip_requesting_account_id = true 88 | } 89 | 90 | ``` 91 | 92 | ### Variables files 93 | 94 | To take profit of this approach we should name the **tfvar** files according to workspaces and in the **variables.tf** load it dynamically. 95 | 96 | **dev.tfvars** 97 | 98 | ``` 99 | env_name = "development" 100 | env_prefix = "dev" 101 | ``` 102 | 103 | And then map it in **variables.tf** 104 | 105 | ``` 106 | variable "env_prefix" { 107 | type = string 108 | description = "Environment name prefix" 109 | } 110 | ``` 111 | 112 | It is possible also to have a global version of variables that may be used in all environment. There is a example of it on the code as well. 113 | 114 | **globals.tfvars** 115 | 116 | ``` 117 | aws_region = "eu-central-1" 118 | project_id = "1a2b3c4d5e6f" 119 | project_name = "Internal project name" 120 | ``` 121 | 122 | ### Defining the resources 123 | 124 | **vpc.tf** 125 | 126 | ``` 127 | resource "aws_vpc" "main" { 128 | cidr_block = "10.0.0.0/16" 129 | 130 | tags = { 131 | Environment = var.env_name 132 | Project_Name = var.project_name 133 | } 134 | } 135 | ``` 136 | 137 | ### Provisioning 138 | 139 | You can define the environment var `TF_WORKSPACE` with the name of environment that you're running, to get variables dynamically, exporting it to wide environment `export TF_WORKSPACE="dev"` and then run the plan/apply command, or passing it as instant env var with `TF_WORKSPACE="dev" opentofu plan -var-file=$TF_WORKSPACE.tfvars -var-file=globals.tfvars`. 140 | 141 | ### References 142 | 143 | [Terraform AWS provider](https://registry.terraform.io/providers/hashicorp/aws/latest/docs) 144 | 145 | [Customize Terraform configuration with variables](https://developer.hashicorp.com/terraform/tutorials/configuration-language/variables) 146 | 147 | [Terraform Workspaces](https://developer.hashicorp.com/terraform/language/state/workspaces) 148 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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