Day 44 — What is EC2 & How to Launch Your First Instance

Today I explored Amazon EC2 (Elastic Compute Cloud) — one of the core services in AWS that allows you to rent virtual servers on-demand. I also learned how to configure an EC2 instance, select the right pricing model, and set up security.

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⚙️ What is EC2?

Amazon EC2 provides a web service API for provisioning, managing, and deprovisioning virtual machines (instances) on AWS.

✨ EC2 Features:

• Virtual servers on-demand (called instances)

• Easily scale up/down based on demand

• Pay only for what you use

• Launch with pre-configured Amazon Machine Images (AMIs)

• Deep integration with AWS services (S3, IAM, VPC, etc.)

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💸 EC2 Pricing Models

1. On-Demand – Pay by the second/hour, no long-term commitment.

2. Reserved – Commit for 1 or 3 years to save up to 75%.

3. Spot – Bid for unused capacity. Cost-effective but instances can be terminated anytime.

4. Dedicated Hosts – Physical servers allocated to you for regulatory/compliance needs.

📚 Learn more: EC2 Pricing

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🧰 EC2 Components

🧱 Amazon Machine Image (AMI)

A template with an OS and preinstalled software. Examples:

• Amazon Linux 2

• Ubuntu

• CentOS

💾 Instance Types

Choose based on your needs (CPU, RAM, storage, network). Examples:

• t2.micro (free tier eligible)

• m5.large

• c6g.xlarge

🏷️ Tags

Key-value pairs that help organize and manage your instances.

• Example: Environment=Production, Owner=Shaharyar

🔐 Key Pairs

Used for SSH access. AWS uses public–key cryptography. You download the .pem file during instance creation.

🔒 Security Groups

Act as virtual firewalls that control inbound/outbound traffic.

• Stateful (response traffic is automatically allowed)

• You can define:

  • Inbound Rules (e.g., allow SSH or HTTP)

  • Outbound Rules (e.g., allow all or restrict egress)

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🚀 EC2 Instance Creation — Step by Step

1. Select AMI (e.g., Amazon Linux 2, Ubuntu, CentOS)

2. Choose Instance Type (e.g., t2.micro)

3. Configure Instance Details

4. Add Storage (default 8 GB — adjust as needed)

5. Add Tags (for identification)

6. Configure Security Group

7. Launch & Download Key Pair

8. SSH into Instance:

    chmod 400 your-key.pem
    ssh ec2-user@<public-ip> -i your-key.pem
   

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🔍 Sample Use Case

Requirement Gathering before instance creation:

• 🧪 Environment: Dev, QA, Staging, Production

• 🌐 OS: CentOS

• 🧠 Size: Minimum (1 vCPU, 1 GB RAM)

• 💾 Storage: 5GB (sufficient for a lightweight web app)

• ⚙️ Services: SSH, HTTP, MySQL

• 👤 Owner/User: DevOps Team

• 🏷️ Tags: Project=Toolplate, Env=Dev

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🧠 What I Learned Today

• EC2 = virtual machine in the cloud

• AMIs make launching new instances fast

• Key pairs and security groups are essential for secure access

• Proper tagging and sizing ensures easy resource management

Up next: Amazon EBS and understanding snaptshots in it.

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