Terraform Lab 2 : Attach an S3 Bucket to an EC2 With Terraform 2024

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In today’s fast-paced cloud computing environment, infrastructure as Code has become a cornerstone for managing and deploying resources efficiently. Terraform a popular IaC tool empowers users to define and provision infrastructure seamlessly.

In this blog post we will guid you through the process of creating an Amazon S3 bucket, an EC2 instance and attaching the S3 bucket to the instance using Terraform configurations.

Prerequisites

Before diving into the Terraform configurations, ensure you have the following prerequisites in place,

  1. An AWS account with appropriate access credentials.
  2. Terraform installed on your local machine.

Step 1: Setting up Terraform Configuration Files

Create a directory for your project and inside it, create the followinig Terraform configuration files.

  • main.tf : Define your AWS provider, S3 bucket, and EC2 instance.
  • variables.tf : Declare any variables you may need for customization.
  • out.tf : Specify the outputs you want to display after respurce creation.

Step 2: Writting Terraform Configurations

Open main.tf and include the following basic configurations,

provider "aws" {
  region = "us-east-1"  # Modify this to your desired AWS region
}

resource "aws_s3_bucket" "my_bucket" {
  bucket = "my-unique-bucket-name"
  acl    = "private"
}

resource "aws_instance" "my_instance" {
  ami           = "ami-xxxxxxxxxxxxxxxxx"  # Replace with your desired AMI
  instance_type = "t2.micro"               # Modify instance type as needed

  tags = {
    Name = "MyEC2Instance"
  }
}

Step 3: Defining Variables (Optional)

In variables.tf you can declare variables for more flexibility and reusability. For example,

variable "region" {
  default = "us-east-1"
}

variable "instance_ami" {
  default = "ami-xxxxxxxxxxxxxxxxx"
}

variable "instance_type" {
  default = "t2.micro"
}

Remember to update your main.tf to use these variables accordingly.

Step 4: Outputs Configuration

In outputs.tf define what information you want Terraform to display after applying the configuration,

output "bucket_name" {
  value = aws_s3_bucket.my_bucket.bucket
}

output "instance_ip" {
  value = aws_instance.my_instance.public_ip
}

Step 5: Initializing, Plan and Applying Terraform

Navigate to your project directory in the terminal and run the following commands,

terraform init

Above command initializes your Terraform configuration and downloads the necessary provider plugins.

terraform plan

Above command shows you what Terraform will do before actually doing it. Review the output which should indicate the creation of EC2 and S3 bucket.

terraform apply

Terraform will prompt you to confirm the plan. Type ‘yes’ and press enter.

Step 6: Verifying Resources

Once the Terraform script completes execution log in to your AWS Management Console. You should see the newly created S3 bucket and EC2 instance.

Step 7: Cleaning Up

Once you are done experimenting, it’s essential to clean up your resources to avoid unnecessary charges. Run the following command in the respective directory,

terraform destroy

Conclusion

We have sucessfully created an S3 bucket and an EC2 instance, attaching the S3 busket using Terraform. This streamlined process demonstrates the power and efficiency of infrastructure as code, providing a scalable and reproducible approach to managing AWS resources.

FAQ’s

Q: Do We Need An IAM Role To Access S3 From EC2?

Ans: Yes, we need to assign an IAM role to our EC2 instance with an appropriate policy (like AmazonS3ReadOnlyAccess or custom policy) to grant access to the S3 bucket.

Q: Can We Mount An S3 Bucket to EC2 Instance Directly?

Ans: S3 in an object storage service and cannot be mounted directly like an EBS volume. However we can use tools like s3fs or AWS CLI on the EC2 instance to access and manage S3 files.

Q: What Terraform Resources Do We Need to Attach S3 to EC2?

Ans: We will typically nee the following resources,

  • aws_instance for the EC2 instance.
  • aws_s3_bucket for the S3 bucket.
  • aws_iam_role and aws_iam_instance_profile to assign permissions to the EC2 instance.

Q: How Can We Restrict S3 Access to Specific Buckets For the EC2 Instance?

Ans: We can create a custom IAM policy that only grants access to specific S3 buckets or objects and attach this policy to the IAM role associated with the EC2 instance.

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