How to Manage Terraform State: A Step-by-Step Guide

4 min readAug 27, 2024

We are moving in the 30 days terraform challenge and this is day 6.

In this blog, we’ll explore what Terraform state is, why it’s crucial, and how to manage it effectively. We’ll also walk through practical examples of both local and remote state management, offering best practices along the way.

What is Terraform State?

Terraform’s state is a key part of how it works. This state is stored in a file called terraform.tfstate, which is located in the root directory of your project.
The file keeps a record of all your infrastructure's resources and their properties. It acts as Terraform's "source of truth," letting Terraform know what resources currently exist, and what changes need to be made—whether creating, updating, or deleting resources.
The file contains details like resource IDs, attributes, and dependencies, enabling Terraform to manage your infrastructure effectively.

Why is Terraform State Important?

Terraform state is crucial for a few key reasons:

Keeping Track of Resources: It helps Terraform keep an up-to-date record of your infrastructure, making sure that any changes you make are applied accurately.
Managing Resource Dependencies: The state file helps Terraform understand how resources are connected, so they are set up in the right order.
Planning and Applying Changes: Terraform uses the state file to compare your current setup with the changes you want to make, allowing it to plan and apply those changes effectively.
Removing Unneeded Resources: The state file also helps Terraform identify and remove resources that are no longer needed, which can save costs and improve management.

How to Manage Terraform State

Terraform offers two primary methods for managing state: Local State Management and Remote State Management. Let’s dive into each method.

Local State Management

Local state management is Terraform’s default approach, where the state file is stored locally on your machine. This method is simple and suitable for small projects or personal use.

Example: Local State Management

Initialize Your Project
Start by initializing your Terraform project:

terraform init

2. Create Resources
Define your infrastructure in a Terraform configuration file (main.tf):

resource "aws_instance" "demo" {
  ami           = "ami-0c88g674cbfafe1f0"
  instance_type = "t2.micro"
}

Apply the configuration:

terraform apply

Terraform will create the resources and store the state in a local terraform.tfstate file.

3. Modify Resources
Update your resource configuration, for example, by adding a tag:

resource "aws_instance" "demo" {
  ami           = "ami-0c88g674cbfafe1f0"
  instance_type = "t2.micro"
  tags = {
    Name = "MyDemoInstance"
  }
}

Apply the changes:

terraform apply

4. Delete Resources and Cleanup
To delete resources, remove them from the configuration file and apply the changes:

terraform destroy

Challenges with Local State Management

Limited Collaboration: Local state files are tied to individual machines, making team collaboration difficult.
Risk of Data Loss: If the state file is lost or corrupted, you risk losing critical information about your infrastructure.
Concurrency Issues: Multiple team members working simultaneously can lead to conflicts.

Remote State Management

For team environments or production use cases, remote state management is the recommended approach. In this method, the state file is stored in a shared location, such as Amazon S3, Azure Blob Storage, or Terraform Cloud, enabling better collaboration and data protection.

Example: Remote State Management with Amazon S3

Set Up Remote State Backend In your Terraform configuration, specify the backend to use remote state management:

terraform {
  backend "s3" {
    bucket         = "aws-s3-bucket-demo"
    key            = "statefile.tfstate"
    region         = "us-east-1"
    encrypt        = true
    dynamodb_table = "demo-dynamodb-table"
  }
}

2. Initialize and Apply Initialize your Terraform project:

terraform init -reconfigure

Apply the configuration:

terraform apply

Terraform will store the state file in the S3 bucket, using DynamoDB for state locking.

Benefits of Remote State Management

Improved Collaboration: Team members can access and update the same state file, ensuring everyone works with the most current information.
Increased Security: Cloud storage solutions provide encryption and access control mechanisms.
Better Data Protection: Features like versioning and backups in cloud storage solutions protect your state file from accidental deletion or corruption.

Best Practices for Managing Terraform State

Use Remote State: For better collaboration and recovery, store state remotely in the cloud.
Separate State Files for Each Environment: Keep individual state files for different environments (e.g., production, staging) to avoid unintended changes.
Version Control: Track changes to your Terraform configuration and state files to maintain an audit trail and facilitate rollbacks.
Regular Backups: Regularly back up your state files to ensure recovery in case of unexpected data loss.

Conclusion

Managing Terraform state is crucial for maintaining accurate and efficient infrastructure deployments. Whether you opt for local or remote state management, understanding how Terraform tracks resources and handles concurrency is key to avoiding errors. By following best practices, you can ensure smooth collaboration, data integrity, and a robust infrastructure as code workflow.

and That’s it !

Resources used :

If you want to Access my Notes and the Flashcards I am building you can find them here and it’s going to be updated as long as I move forward in the challenge : https://shadowed-bubble-139.notion.site/30-Day-Terraform-Challenge-dec28b59677845218d72dd4163751c87?pvs=4

That’s all I have for today folks. Thank you for reading and/or following along! I hope this blog was helpful and worth your while. Stay tuned for my next project on this journey into the cloud.

Let’s connect on LinkedIn! 👉 https://www.linkedin.com/in/meriemterki/