Repository files navigation

Terraform module to provision an S3 bucket to storeterraform.tfstate file and a DynamoDB table to lock the state fileto prevent concurrent modifications and state corruption.

The module supports the following:

1. Forced server-side encryption at rest for the S3 bucket
2. S3 bucket versioning to allow for Terraform state recovery in the case of accidental deletions and human errors
3. State locking and consistency checking via DynamoDB table to prevent concurrent operations
4. DynamoDB server-side encryption

https://www.terraform.io/docs/backends/types/s3.html

NOTE: The operators of the module (IAM Users) must have permissions to create S3 buckets and DynamoDB tables when performingterraform plan andterraform apply

NOTE: This module cannot be used to apply changes to themfa_delete feature of the bucket. Changes regarding mfa_delete can only be made manually using the root credentials with MFA of the AWS Account where the bucket resides. Please see:hashicorp/terraform-provider-aws#629

Tip

👽 Use Atmos with Terraform

Cloud Posse usesatmos to easily orchestrate multiple environments using Terraform.
Works withGithub Actions,Atlantis, orSpacelift.

Watch demo of using Atmos with Terraform

Example of runningatmos to manage infrastructure from ourQuick Start tutorial.

Follow this procedure just once to create your deployment.

1. Add theterraform_state_backend module to yourmain.tf file. Thecomment will help you remember to follow this procedure in the future:

   # You cannot create a new backend by simply defining this and then# immediately proceeding to "terraform apply". The S3 backend must# be bootstrapped according to the simple yet essential procedure in# https://github.com/cloudposse/terraform-aws-tfstate-backend#usagemodule"terraform_state_backend" {source="cloudposse/tfstate-backend/aws"# Cloud Posse recommends pinning every module to a specific version# version     = "x.x.x"namespace="eg"stage="test"name="terraform"attributes=["state"]terraform_backend_config_file_path="."terraform_backend_config_file_name="backend.tf"force_destroy=false}# Your Terraform configurationmodule"another_module" {source="....."}

   Module inputsterraform_backend_config_file_path andterraform_backend_config_file_name control the name of the backenddefinition file. Note that whenterraform_backend_config_file_path isempty (the default), no file is created.

2. terraform init. This downloads Terraform modules and providers.

3. terraform apply -auto-approve. This creates the state bucket and DynamoDB lockingtable, along with anything else you have defined in your*.tf file(s). Atthis point, the Terraform state is still stored locally.

   Moduleterraform_state_backend also creates a newbackend.tf filethat defines the S3 state backend. For example:

   backend"s3" {region="us-east-1"bucket="< the name of the S3 state bucket >"key="terraform.tfstate"dynamodb_table="< the name of the DynamoDB locking table >"profile=""role_arn=""encrypt=true}

   Henceforth, Terraform will also read this newly-created backend definitionfile.

4. terraform init -force-copy. Terraform detects that you want to move yourTerraform state to the S3 backend, and it does so per-auto-approve. Now thestate is stored in the S3 bucket, and the DynamoDB table will be used to lockthe state to prevent concurrent modification.

This concludes the one-time preparation. Now you can extend and modify yourTerraform configuration as usual.

Follow this procedure to delete your deployment.

1. Inmain.tf, change theterraform_state_backend module arguments asfollows:

   module"terraform_state_backend" {# ...terraform_backend_config_file_path=""force_destroy=true }

2. terraform apply -target module.terraform_state_backend -auto-approve.This implements the above modifications by deleting thebackend.tf fileand enabling deletion of the S3 state bucket.
3. terraform init -force-copy. Terraform detects that you want to move yourTerraform state from the S3 backend to local files, and it does so per-auto-approve. Now the state is once again stored locally and the S3state bucket can be safely deleted.
4. terraform destroy. This deletes all resources in your deployment.
5. Examine local state fileterraform.tfstate to verify that it containsno resources.

To enable S3 bucket replication in this module, sets3_replication_enabled totrue and populates3_replica_bucket_arn with the ARN of an existing bucket.

module"terraform_state_backend" {source="cloudposse/tfstate-backend/aws"# Cloud Posse recommends pinning every module to a specific version# version     = "x.x.x"namespace="eg"stage="test"name="terraform"attributes=["state"]terraform_backend_config_file_path="."terraform_backend_config_file_name="backend.tf"force_destroy=falses3_replication_enabled=trues3_replica_bucket_arn="arn:aws:s3:::eg-test-terraform-tfstate-replica"}

{
  "additional_tag_map": {},
  "attributes": [],
  "delimiter": null,
  "descriptor_formats": {},
  "enabled": true,
  "environment": null,
  "id_length_limit": null,
  "label_key_case": null,
  "label_order": [],
  "label_value_case": null,
  "labels_as_tags": [
    "unset"
  ],
  "name": null,
  "namespace": null,
  "regex_replace_chars": null,
  "stage": null,
  "tags": {},
  "tenant": null
}

[
  "default"
]

list(object({
    target_bucket = string
    target_prefix = string
  }))

Check out these related projects.

• terraform-aws-dynamodb - Terraform module that implements AWS DynamoDB with support for AutoScaling
• terraform-aws-dynamodb-autoscaler - Terraform module to provision DynamoDB autoscaler

This project is under active development, and we encourage contributions from our community.

Many thanks to our outstanding contributors:

For 🐛 bug reports & feature requests, please use theissue tracker.

In general, PRs are welcome. We follow the typical "fork-and-pull" Git workflow.

1. Review ourCode of Conduct andContributor Guidelines.
2. Fork the repo on GitHub
3. Clone the project to your own machine
4. Commit changes to your own branch
5. Push your work back up to your fork
6. Submit aPull Request so that we can review your changes

NOTE: Be sure to merge the latest changes from "upstream" before making a pull request!

We useAtmos to streamline how Terraform tests are run. It centralizes configuration and wraps common test workflows with easy-to-use commands.

All tests are located in thetest/ folder.

Under the hood, tests are powered by Terratest together with our internalTest Helpers library, providing robust infrastructure validation.

Setup dependencies:

• Install Atmos (installation guide)
• Install Go1.24+ or newer
• Install Terraform or OpenTofu

To run tests:

• Run all tests:

  atmostest run

• Clean up test artifacts:

  atmostest clean

• Explore additional test options:

  atmostest --help

The configuration for test commands is centrally managed. To review what's being imported, see theatmos.yaml file.

Learn more about ourautomated testing in our documentation or implementingcustom commands with atmos.

Join ourOpen Source Community on Slack. It'sFREE for everyone! Our "SweetOps" community is where you get to talk with others who share a similar vision for how to rollout and manage infrastructure. This is the best place to talk shop, ask questions, solicit feedback, and work together as a community to build totallysweet infrastructure.

Sign up forour newsletter and join 3,000+ DevOps engineers, CTOs, and founders who get insider access to the latest DevOps trends, so you can always stay in the know.Dropped straight into your Inbox every week — and usually a 5-minute read.

Join us every Wednesday via Zoom for your weekly dose of insider DevOps trends, AWS news and Terraform insights, all sourced from our SweetOps community, plus alive Q&A that you can’t find anywhere else.It'sFREE for everyone!

Licensed to the Apache Software Foundation (ASF) under oneor more contributor license agreements.  See the NOTICE filedistributed with this work for additional informationregarding copyright ownership.  The ASF licenses this fileto you under the Apache License, Version 2.0 (the"License"); you may not use this file except in compliancewith the License.  You may obtain a copy of the License at  https://www.apache.org/licenses/LICENSE-2.0Unless required by applicable law or agreed to in writing,software distributed under the License is distributed on an"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANYKIND, either express or implied.  See the License for thespecific language governing permissions and limitationsunder the License.

All other trademarks referenced herein are the property of their respective owners.

Copyright © 2017-2025Cloud Posse, LLC