AWS S3 Storage Basics

# CHAPTER 6

AWS S3 Storage Basics #

1. Introduction #

2. Learning Objectives #

• Define Object Storage and contrast it with traditional Block Storage.

• Create an S3 Bucket with globally unique naming.

• Upload and manage Objects within a bucket.

• Understand S3 Bucket Policies and Block Public Access settings.

• Host a scalable Static Website using only S3.

3. Beginner-Friendly Explanation #

Now imagine a massive warehouse managed by robots (S3 / Object Storage). There are no folders. You hand a robot a box (a photo). The robot tags the box with a unique barcode (a URL), throws it onto a massive, infinitely expanding pile, and hands you the barcode. Whenever you want the photo, you just scan the barcode, and the robot retrieves it instantly. You never have to worry about the warehouse running out of space.

4. Buckets and Objects #

• Buckets: The massive root container holding your files. Bucket names must be globally unique across ALL AWS accounts in the world. (You cannot name your bucket my-bucket because someone else already took it).

• Objects: The actual files (images, videos, text files) you upload into the bucket. Each object gets a unique URL.

5. Infinite Scaling and Durability #

6. S3 Security (Block Public Access) #

7. Mini Project: Host a Static Website on S3 #

Step-by-Step Tutorial:

1. 1. Open the AWS Console and search for S3.

1. 2. Click Create bucket.

1. 3. Bucket name: Enter something globally unique (e.g., my-aws-website-yourname-123).

1. 4. Object Ownership: Leave as ACLs disabled.

1. 5. Block Public Access settings: UNCHECK the box that says "Block *all* public access." Acknowledge the warning. (We are hosting a public website, so it must be public!). Click Create bucket.

1. 6. Click into your new bucket. Go to the Properties tab.

1. 7. Scroll to the very bottom: Static website hosting. Click Edit.

1. 8. Select Enable. For the Index document, type index.html. Save changes.

1. 9. Go to the Permissions tab. Scroll to Bucket policy. Click Edit and paste this JSON policy (Replace YOUR-BUCKET-NAME):

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "PublicReadGetObject",
            "Effect": "Allow",
            "Principal": "*",
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::YOUR-BUCKET-NAME/*"
        }
    ]
}

1. 10. Go to the Objects tab. Click Upload. Upload a simple index.html file from your computer.

1. 11. Go back to Properties -> Static website hosting, and click the provided Bucket website endpoint URL. Your website is live to the world!

8. Best Practices #

• Use IAM for Private Access: If your EC2 web server needs to read private user photos from an S3 bucket, DO NOT make the bucket public. Attach an IAM Role to the EC2 instance granting it s3:GetObject permissions. The EC2 server will magically be able to read the private bucket securely.

9. Common Mistakes #

• Confusing S3 with a Database: You cannot query S3 like a SQL database. You cannot say "Find all images uploaded by user John." S3 only retrieves objects by their exact Key (Filename). Metadata indexing requires a separate database (like DynamoDB) storing the S3 URLs.

10. Exercises #

1. 1. Explain why S3 is an ideal storage solution for serving static images for a website compared to storing them directly on the EC2 instance's EBS volume.

11. MCQs with Answers #

12. Interview Questions #

• Q: Explain the difference between Block Storage (like AWS EBS) and Object Storage (like AWS S3). In what architectural scenarios would you use one over the other?

• Q: Explain the 11 9s of Durability guarantee in S3. How does AWS physically architect its infrastructure to provide this level of data protection against hardware failure?

13. FAQs #

14. Summary #

15. Next Chapter Recommendation #