EC2: Elastic Compute Cloud

Master EC2 virtual servers including instance types, security groups, key pairs, and how to launch and manage cloud servers for your applications.

35 minutes

EC2: Elastic Compute Cloud

Amazon EC2 provides resizable compute capacity in the cloud. It's like renting virtual servers that you can configure and manage yourself.

What is EC2?

Virtual Servers: Run applications on virtual machines
Flexible Configuration: Choose CPU, memory, storage, and networking
Pay Per Use: Only pay for the compute time you use
Quick Deployment: Launch instances in minutes

EC2 Instance Types

AWS offers different instance families optimized for various use cases:

General Purpose (T3, T4g, M5, M6i)

Balanced compute, memory, and networking
Great for web servers and small databases
Example: t3.micro, t3.medium, m5.large

Compute Optimized (C5, C6i, C7g)

High-performance processors
Ideal for batch processing, web servers, gaming
Example: c5.xlarge, c6i.2xlarge

Memory Optimized (R5, R6i, X2)

High memory-to-CPU ratio
Perfect for databases and in-memory caching
Example: r5.large, r6i.xlarge

Storage Optimized (I3, D2, H1)

High sequential read/write access
Ideal for data warehousing and log processing
Example: i3.large, d2.xlarge

Key EC2 Concepts

AMIs (Amazon Machine Images)

Pre-configured templates for instances
Include OS, applications, and configurations
Can create custom AMIs from existing instances

Security Groups

Virtual firewalls for instances
Control inbound and outbound traffic
Stateful - return traffic is automatically allowed

Key Pairs

Public-key cryptography for SSH access
Keep private key secure
Used to connect to Linux instances

Instance States

Running: Instance is active and billing
Stopped: Instance is shut down, only storage billed
Terminated: Instance is deleted permanently

Launching an EC2 Instance

Choose an AMI (Amazon Linux, Ubuntu, etc.)
Select instance type based on your needs
Configure instance details (network, IAM role)
Add storage (EBS volumes)
Add tags for organization
Configure security group
Review and launch with key pair

Best Practices

Use IAM roles instead of embedding credentials
Enable detailed monitoring for production instances
Use Elastic IPs for static IP addresses
Regular backups with AMIs or snapshots
Right-size instances based on actual usage
Use Auto Scaling for high availability

Code Example

# Launch an EC2 instance using AWS CLI

# Create a security group
aws ec2 create-security-group \
  --group-name web-server-sg \
  --description "Security group for web server"

# Add inbound rules to security group
aws ec2 authorize-security-group-ingress \
  --group-name web-server-sg \
  --protocol tcp \
  --port 22 \
  --cidr 0.0.0.0/0  # SSH access

aws ec2 authorize-security-group-ingress \
  --group-name web-server-sg \
  --protocol tcp \
  --port 80 \
  --cidr 0.0.0.0/0  # HTTP access

# Create a key pair
aws ec2 create-key-pair \
  --key-name my-key-pair \
  --query 'KeyMaterial' \
  --output text > my-key-pair.pem

chmod 400 my-key-pair.pem

# Launch an EC2 instance
aws ec2 run-instances \
  --image-id ami-0c55b159cbfafe1f0 \
  --instance-type t3.micro \
  --key-name my-key-pair \
  --security-groups web-server-sg \
  --count 1 \
  --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=MyWebServer}]'

# List running instances
aws ec2 describe-instances \
  --filters "Name=instance-state-name,Values=running" \
  --query 'Reservations[*].Instances[*].[InstanceId,InstanceType,PublicIpAddress,State.Name]' \
  --output table

# Connect to instance via SSH
ssh -i my-key-pair.pem ec2-user@<PUBLIC_IP_ADDRESS>

# Stop an instance
aws ec2 stop-instances --instance-ids i-1234567890abcdef0

# Start an instance
aws ec2 start-instances --instance-ids i-1234567890abcdef0

# Terminate an instance
aws ec2 terminate-instances --instance-ids i-1234567890abcdef0

# Create an AMI from a running instance
aws ec2 create-image \
  --instance-id i-1234567890abcdef0 \
  --name "MyWebServer-Backup" \
  --description "Backup of web server"

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