README.md

terraform-master

This terraform project initialises a account to become the root account of an AWS Organisation.

Initalise Master Account and Setup Terraform

The following steps are required initalise the master account and terraforms first run. Best practice is to create a tfvars file to supply the variables. The *.tfvars.example file can be renamed to *.tfvars and updated with the appropriate variables.

The .gitignore is setup to ignore any .tfvars variable files as they could contain sensitive information.

1. Create a AWS account to be the master account and then run the CloudFormation script in init/terraform-init.yaml. The CloudFormation script creates the following resources:

   • Terraform User and Credentials

2. Setup the AWS profile using aws configure --profile terraform-master. The outputs of the CloudFormation script should be used when prompted.

3. Run terraform init "-var-file=master.tfvars"

4. Run terraform plan "-var-file=master.tfvars" ensure the appropriate resources are being created. Especially the KMS key and S3 bucket.

5. Run terraform apply "-var-file=master.tfvars"

6. Update the master.tfvars file with the outputs from the terraform apply stage.

7. Add the following backend configuration to the top of main.tf.

terraform {
 backend "s3" {
   key     = "common/master"
   encrypt = true
 }
}

7. Run terraform init "-backend-config=backend.tfvars" again and select yes to migrate the state.

8. As the root user login and enable the DenyCloudTrailModifications policy.

• Navigate to AWS Organizations
• Click on the Organize accounts tab
• On the right hand side under Root click Enable for Service control policies
• Click on the Policies tab
• Select the ProtectAccounts policy
• Select Accounts from the right hand side
• Click Attach for all of the accounts listed

User Terraform Setup

Once the state has been stored in S3, users have to run the following command if they are setting up their local environment or if you ever set or change modules or backend configuration for Terraform.

• terraform init "-backend-config=backend.tfvars"

Inputs

Name	Description	Type	Default	Required
aws_default_region	The AWS Region to create resources	string	-	yes
domain_name	The domain name which will be used as the suffix for s3 buckets and email addresses	string	-	yes
master_account_id	The account id which will be the root organisation	string	-	yes
account_prefix	The prefix to use for account aliases	string	-	yes
profile	A profile in ~/.aws/credentials which is used for terraform	string	default	no
tags	A map of tags to add to all resources	map	{}	no

Outputs

Name	Description
cloudtrail_bucket_id	The name of the cloudtrail bucket where all trails will be centralised
default_kms_key_arn	The KMS Key id which can be used by all users and AWS services
development_account_alias	The alias of the development account
development_account_id	The development account id
development_cloudtrail_log_name	The name of the cloudtrail log for the development account
master_account_alias	The alias of the root account
master_account_id	The root account id
master_cloudtrail_log_name	The name of the cloudtrail log for the master account
operations_account_alias	The alias of the operations account
operations_account_id	The operation account id
operations_cloudtrail_log_name	The name of the cloudtrail log for the operations account
production_account_alias	The alias of the production account
production_account_id	The production account id
production_cloudtrail_log_name	The name of the cloudtrail log for the production account
terraform_access_key_id	The Terraform User Access Key ID
terraform_bucket_id	The name of the terraform state bucket
terraform_dynamodb_table_name	The name of the terraform dynamodb table
terraform_kms_key_arn	The KMS Key id used by terraform to encrypt the s3 bucket at rest
terraform_secret_access_key	The Terraform User Secret Access Key