README.md

terraform-aws-remote-state-s3-backend

Terraform Module Registry

A terraform module to set up remote state management with S3 backend for your account. It creates an encrypted S3 bucket to store state files and a DynamoDB table for state locking and consistency checking. Resources are defined following best practices as described in the official document and ozbillwang/terraform-best-practices.

Features

• Create a S3 bucket to store remote state files.
• Encrypt state files with KMS.
• Enable bucket replication and object versioning to prevent accidental data loss.
• Automatically transit non-current versions in S3 buckets to AWS S3 Glacier to optimize the storage cost.
• Optionally you can set to expire aged non-current versions(disabled by default).
• Optionally you can set fixed S3 bucket name to be user friendly(false by default).
• Create a DynamoDB table for state locking, encryption is optional.
• Optionally create an IAM policy to allow permissions which Terraform needs.

Usage

The module outputs terraform_iam_policy which can be attached to IAM users, groups or roles running Terraform. This will allow the entity accessing remote state files and the locking table. This can optionally be disabled with terraform_iam_policy_create = false

provider "aws" {
  region = "us-east-1"
}

provider "aws" {
  alias  = "replica"
  region = "us-west-1"
}

module "remote_state" {
  source = "nozaq/remote-state-s3-backend/aws"

  providers = {
    aws         = aws
    aws.replica = aws.replica
  }
}

resource "aws_iam_user" "terraform" {
  name = "TerraformUser"
}

resource "aws_iam_user_policy_attachment" "remote_state_access" {
  user       = aws_iam_user.terraform.name
  policy_arn = module.remote_state.terraform_iam_policy.arn
}

Note that you need to provide two providers, one for the main state bucket and the other for the bucket to which the main state bucket is replicated to. Two providers must point to different AWS regions.

Once resources are created, you can configure your terraform files to use the S3 backend as follows.

terraform {
  backend "s3" {
    bucket         = "THE_NAME_OF_THE_STATE_BUCKET"
    key            = "some_environment/terraform.tfstate"
    region         = "us-east-1"
    encrypt        = true
    kms_key_id     = "THE_ID_OF_THE_KMS_KEY"
    dynamodb_table = "THE_ID_OF_THE_DYNAMODB_TABLE"
  }
}

THE_NAME_OF_THE_STATE_BUCKET, THE_ID_OF_THE_DYNAMODB_TABLE and THE_ID_OF_THE_KMS_KEY can be replaced by state_bucket.bucket, dynamodb_table.id and kms_key.id in outputs from this module respectively.

See the official document for more detail.

Compatibility

• Starting from v1.0, this module requires Terraform Provider for AWS v4.0 or later. Version 1.0 Upgrade Guide described the recommended procedure after the upgrade.

Requirements

Name	Version
terraform	>= 1.1.4
aws	>= 4.3

Providers

Name	Version
aws	>= 4.3
aws.replica	>= 4.3

Inputs

Name	Description	Type	Required
dynamodb_deletion_protection_enabled	Whether or not to enable deletion protection on the DynamoDB table	bool	no
dynamodb_enable_server_side_encryption	Whether or not to enable encryption at rest using an AWS managed KMS customer master key (CMK)	bool	no
dynamodb_table_billing_mode	Controls how you are charged for read and write throughput and how you manage capacity.	string	no
dynamodb_table_name	The name of the DynamoDB table to use for state locking.	string	no
enable_replication	Set this to true to enable S3 bucket replication in another region	bool	no
iam_policy_attachment_name	The name of the attachment.	string	no
iam_policy_name	If override_iam_policy_name is true, use this policy name instead of dynamic name with policy_prefix	string	no
iam_policy_name_prefix	Creates a unique name beginning with the specified prefix.	string	no
iam_role_arn	Use IAM role of specified ARN for s3 replication instead of creating it.	string	no
iam_role_name	If override_iam_role_name is true, use this role name instead of dynamic name with role_prefix	string	no
iam_role_name_prefix	Creates a unique name beginning with the specified prefix.	string	no
iam_role_permissions_boundary	Use permissions_boundary with the replication IAM role.	string	no
kms_key_alias	The alias for the KMS key as viewed in AWS console. It will be automatically prefixed with alias/	string	no
kms_key_deletion_window_in_days	Duration in days after which the key is deleted after destruction of the resource, must be between 7 and 30 days.	number	no
kms_key_description	The description of the key as viewed in AWS console.	string	no
kms_key_enable_key_rotation	Specifies whether key rotation is enabled.	bool	no
noncurrent_version_expiration	Specifies when noncurrent object versions expire. See the aws_s3_bucket document for detail.	object({ days = number })	no
noncurrent_version_transitions	Specifies when noncurrent object versions transitions. See the aws_s3_bucket document for detail.	list(object({ days = number storage_class = string }))	no
override_iam_policy_name	override iam policy name to disable policy_prefix and create policy with static name	bool	no
override_iam_role_name	override iam role name to disable role_prefix and create role with static name	bool	no
override_s3_bucket_name	override s3 bucket name to disable bucket_prefix and create bucket with static name	bool	no
override_terraform_iam_policy_name	override terraform iam policy name to disable policy_prefix and create policy with static name	bool	no
replica_bucket_prefix	Creates a unique replica bucket name beginning with the specified prefix.	string	no
s3_bucket_force_destroy	A boolean that indicates all objects should be deleted from S3 buckets so that the buckets can be destroyed without error. These objects are not recoverable.	bool	no
s3_bucket_name	If override_s3_bucket_name is true, use this bucket name instead of dynamic name with bucket_prefix	string	no
s3_bucket_name_replica	If override_s3_bucket_name is true, use this bucket name for replica instead of dynamic name with bucket_prefix	string	no
s3_logging_target_bucket	The name of the bucket for log storage. The "S3 log delivery group" should have Objects-write und ACL-read permissions on the bucket.	string	no
s3_logging_target_prefix	The prefix to apply on bucket logs, e.g "logs/".	string	no
state_bucket_prefix	Creates a unique state bucket name beginning with the specified prefix.	string	no
tags	A mapping of tags to assign to resources.	map(string)	no
terraform_iam_policy_create	Specifies whether to terraform IAM policy is created.	bool	no
terraform_iam_policy_name	If override_terraform_iam_policy_name is true, use this policy name instead of dynamic name with policy_prefix	string	no
terraform_iam_policy_name_prefix	Creates a unique name beginning with the specified prefix.	string	no

Outputs

Name	Description
dynamodb_table	The DynamoDB table to manage lock states.
kms_key	The KMS customer master key to encrypt state buckets.
kms_key_alias	The alias of the KMS customer master key used to encrypt state bucket and dynamodb.
kms_key_replica	The KMS customer master key to encrypt replica bucket and dynamodb.
replica_bucket	The S3 bucket to replicate the state S3 bucket.
state_bucket	The S3 bucket to store the remote state file.
terraform_iam_policy	The IAM Policy to access remote state environment.