🚀 Terraform Remote Backend with S3 and DynamoDB

📌 Introduction

When using Terraform in real-world projects, managing state locally (terraform.tfstate) can become risky. If multiple engineers apply changes at the same time, the state file may get corrupted.

To solve this, Terraform supports remote backends. In this project, I implemented a Terraform Remote Backend using AWS S3 and DynamoDB.

• S3 Bucket → Stores Terraform state files centrally.

• DynamoDB Table → Ensures state locking and consistency.

Alongside the backend, this project also provisions an EC2 instance on AWS.

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⚙️ Project Structure

backend-project/
├── main.tf       # Defines AWS resources (EC2, S3, DynamoDB)
├── backend.tf    # Configures Terraform remote backend

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🛠️ Step 1: Define AWS Resources

In main.tf, we define three resources:

1. EC2 Instance → A simple t3.micro instance.

2. S3 Bucket → To store .tfstate files.

3. DynamoDB Table → For state locking.

provider "aws" { 
  region = "eu-north-1"
}

resource "aws_instance" "harshal" {
  instance_type = "t3.micro"
  ami           = "ami-042b4708b1d05f512"
}

resource "aws_s3_bucket" "s3_bucket" {
  bucket = "harshal-bucket-s3buck"
}

resource "aws_dynamodb_table" "terraform-lock" {
  name         = "terraform-lock"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "LockID"

  attribute {
    name = "LockID"
    type = "S"
  } 
}

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🛠️ Step 2: Configure Remote Backend

In backend.tf, we configure Terraform to use the S3 bucket and DynamoDB table created above.

terraform {
  backend "s3" {
    bucket         = "harshal-bucket-s3buck"
    key            = "harshal/terraform.tfstate"
    region         = "eu-north-1"
    dynamodb_table = "terraform-lock"
  }
}

• bucket → Name of your S3 bucket.

• key → Path inside the bucket where state file is stored.

• dynamodb_table → Table used for locking.

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🛠️ Step 3: Initialize and Apply

Run the following commands:

# Initialize Terraform with remote backend
terraform init  

# Review execution plan
terraform plan  

# Apply configuration
terraform apply

✅ After applying, your:

• EC2 instance will be provisioned.

• Terraform state file will be stored in S3.

• State locking will be handled by DynamoDB.

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✅ Why Remote Backend?

1. Collaboration Ready → Teams can work on the same infrastructure without conflicts.

2. State Locking → DynamoDB ensures no two users modify state simultaneously.

3. Disaster Recovery → S3 versioning allows rollback of previous state.

4. Security → State file is stored safely in AWS instead of local machines.

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📂 Project Repository

🔗 Terraform Backend Project on GitHub

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👨‍💻 Author

Harshal Vernekar

• GitHub: @Harshalv21

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👉 With this setup, you now have a production-ready Terraform workflow using S3 + DynamoDB for state management.