Amazon S3: Bucket Creation and Object Management

Topics: S3, Object Storage, Bucket Management, Public Access, ACLs

Overview

Amazon S3 (Simple Storage Service) is AWS's foundational object storage service, designed for storing and retrieving unlimited amounts of data from anywhere on the web. Unlike traditional file systems that organize data in hierarchical folders, S3 uses a flat structure where objects (files) are stored in buckets (containers).

This lab introduces you to core S3 concepts, creating S3 bucket, uploading objects, and configuring public access permissions. You'll learn about S3's architecture, storage classes, and security models, including the difference between ACLs and bucket policies.

S3's durability (99.999999999%) and availability (99.99%) make it ideal for critical data storage across industries, from startups to enterprises.

Key Concepts

Concept	Description
S3 Bucket	Top-level container for storing objects; globally unique name required
Object	Individual file stored in S3 with data, metadata, and unique key (name)
Object Key	Unique identifier for an object within a bucket (essentially the file name/path)
Metadata	Information about the object such as content type, creation date, and custom tags
ACL (Access Control List)	Legacy permission mechanism for individual objects or buckets
Bucket Policy	JSON-based permission document that applies to entire bucket (modern approach)
Storage Class	Pricing tier based on access frequency (Standard, Intelligent-Tiering, Glacier, etc.)
Durability	Probability of data loss; S3 offers 99.999999999% (11 nines) durability
Availability	Percentage of time data is accessible; S3 Standard offers 99.99% availability
Public Access	Configuration allowing internet users to access objects without AWS credentials

Prerequisites

• Active AWS account (Free Tier eligible)
• Image file or any test file for upload
• Basic understanding of cloud storage concepts
• Web browser for accessing uploaded public objects

S3 Public Object Workflow

This diagram visualizes the specific configuration steps required to make an object accessible via a public URL.

Click to expand Architecture Diagram

Create S3 Bucket and Upload Objects

1. Sign in to your AWS Management Console.

2. Navigate to S3 service:

   • In the search bar, type S3
   • Click Amazon S3

3. Click Create bucket.

4. Configure bucket settings:

   • Bucket type: General purpose
   • Bucket name: Enter a globally unique name
     • Must be lowercase
     • Can contain letters, numbers, and hyphens
     • Example: student1-lab3-assets-2025-xy or yourname-demo-bucket-jan2026
   • AWS Region: Select the region nearest to you (e.g., us-east-1, ap-south-1)

5. Configure Object Ownership:

   • Expand Object Ownership section
   • Select ACLs enabled
   • Keep Bucket owner preferred checked (default)

ACLs vs Bucket Policies

• ACLs (Access Control Lists) are a legacy mechanism for controlling access to individual objects
• Bucket Policies are modern JSON-based rules that apply to entire buckets
• In production environments, bucket policies are preferred, but ACLs are useful for learning and simple use cases

6. Configure public access settings:

   • Scroll down to Block Public Access settings for this bucket
   • Uncheck "Block all public access"
   • A warning dialog appears
   • Check the acknowledgment box: "I acknowledge that the current settings might result in this bucket and the objects within becoming public"

7. Leave all other settings at default:

   • Bucket Versioning: Disabled
   • Tags: None
   • Default encryption: Amazon S3-managed keys (SSE-S3)

8. Click Create bucket.

9. Your bucket is now created and appears in the S3 bucket list.

10. Upload an object to the bucket:

    • Click on your bucket name to open it
    • Click Upload button
    • Click Add files
    • Select an image file (JPG, PNG, GIF) or any test file from your computer
    • Click Upload at the bottom

11. Wait for the upload to complete (green success banner appears).

12. Make the object publicly accessible:

    • Navigate to the Objects tab in your bucket
    • Select the uploaded file by checking the checkbox next to it
    • Click Actions dropdown menu
    • Select Make public using ACL
    • A confirmation dialog appears
    • Click Make public

13. Access the object via public URL:

    • Click on the object name to view its details
    • Scroll down to the Object overview section
    • Find the Object URL field
    • Copy the URL (format: https://<bucket-name>.s3.<region>.amazonaws.com/<filename>)
    • Open the URL in a new browser tab
    • The image/file is displayed directly from S3

URL Structure

https://<bucket-name>.s3.<region>.amazonaws.com/<object-key>

• <bucket-name>: Your unique bucket name
• <region>: AWS region where bucket is created
• <object-key>: The file name (or path if using prefixes)

Validation

Validation

Verify successful completion:

• Bucket Creation:

  • Bucket appears in S3 bucket list
  • Bucket name is globally unique and follows naming rules
  • Bucket region matches your selection
  • Public access settings show "Public" label

• Object Upload:

  • Object appears in the Objects tab
  • File size and type are correct
  • Upload completed without errors

• Public Access:

  • Object has "Publicly accessible" label
  • Object URL opens in browser successfully
  • Image/file displays without authentication required
  • No "Access Denied" errors

Cost Considerations

Cost Considerations

• S3 Standard Storage:

  • First 50 TB: $0.023 per GB/month
  • Next 450 TB: $0.022 per GB/month
  • Storage costs calculated by average storage per month

• Free Tier (First 12 months):

  • 5 GB of S3 Standard storage
  • 20,000 GET requests
  • 2,000 PUT requests
  • 100 GB of data transfer out

• Data Transfer:

  • Data transfer IN to S3: Free
  • Data transfer OUT to internet: $0.09 per GB (after free tier)
  • First 100 GB/month out is free

• Requests:

  • PUT, COPY, POST, LIST: $0.005 per 1,000 requests
  • GET, SELECT: $0.0004 per 1,000 requests

Cleanup

Cleanup

To avoid ongoing costs and maintain good AWS hygiene:

1. Delete objects first:

   • Open your S3 bucket
   • Go to the Objects tab
   • Select all objects (checkbox at top)
   • Click Delete
   • Type permanently delete in the confirmation field
   • Click Delete objects

2. Delete the bucket:

   • Return to the S3 console (bucket list)
   • Select your bucket (checkbox)
   • Click Delete
   • Type the bucket name in the confirmation field
   • Click Delete bucket

Deletion Requirement

S3 buckets must be empty before they can be deleted. Always empty buckets first, then delete them.

Result

You have successfully created your first Amazon S3 bucket, uploaded objects, and configured public access. You now understand S3's fundamental concepts including buckets, objects, regions, and access control mechanisms. The public object URL demonstrates S3's capability to serve content directly over HTTP, which is the foundation for static website hosting, CDN integration, and public file sharing.

These skills are essential for leveraging S3 across numerous AWS use cases, from simple file storage to complex data lakes and application architectures.

Viva Questions

1. What is the difference between Amazon S3 and traditional file systems?

   • S3 is object-based storage with a flat structure where files (objects) are stored in buckets with unique keys. Traditional file systems use hierarchical directory structures. S3 offers unlimited scalability, built-in redundancy, and HTTP-based access, while file systems are limited by disk capacity and require manual backup configurations.

2. Why must S3 bucket names be globally unique?

   • S3 bucket names form part of the DNS namespace and are used in URLs (bucket-name.s3.amazonaws.com). Since DNS names must be globally unique across the internet, bucket names must also be globally unique across all AWS accounts worldwide to prevent conflicts.

3. What is the difference between ACLs and Bucket Policies in S3?

   • ACLs (Access Control Lists) are legacy permission mechanisms that apply to individual objects or buckets with limited permission options. Bucket Policies are modern JSON-based documents that provide fine-grained control over entire buckets and can specify conditions, principals, and actions. AWS recommends using Bucket Policies for most use cases.

4. What does S3's 99.999999999% durability mean?

   • This means if you store 10,000,000 objects in S3, you can expect to lose one object every 10,000 years on average. S3 achieves this by automatically storing multiple copies of data across multiple Availability Zones within a region, providing extreme data protection against hardware failures.

5. What are the main use cases for Amazon S3?

   • Backup and disaster recovery, data archival, static website hosting, media file storage and distribution, data lakes for analytics, application data storage, content delivery (with CloudFront), log file storage, and software distribution.