☁️ Week 5: AWS Cloud

Day 2: EC2 Fundamentals

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⏱ Duration: 5 Hours

📚 Learning Objectives

  • Understand EC2 and its use cases
  • Learn about instance types and families
  • Create and manage key pairs
  • Configure security groups
  • Launch and connect to EC2 instances

📖 Core Concepts (2 Hours)

What is EC2?

Amazon Elastic Compute Cloud (EC2) provides scalable virtual servers in the cloud. It's the backbone of AWS compute services.

  • Instances: Virtual servers running your applications
  • AMI: Amazon Machine Image - template for instances
  • Instance Types: CPU, memory, storage configurations
  • Security Groups: Virtual firewall for instances
  • Key Pairs: SSH keys for secure access

EC2 Instance Types

Instance Type Format: [Family][Generation].[Size] Example: t3.medium, m5.large, c6i.xlarge Instance Families: ├── General Purpose (t3, m5, m6i) │ └── Balanced compute, memory, networking │ ├── Compute Optimized (c5, c6i) │ └── High-performance processors │ ├── Memory Optimized (r5, r6i, x2) │ └── Large datasets in memory │ ├── Storage Optimized (i3, d2) │ └── High sequential read/write │ └── Accelerated Computing (p4, g5) └── GPU instances for ML/graphics Free Tier: t2.micro or t3.micro (750 hours/month)

Amazon Machine Images (AMIs)

AMI Types: ├── AWS Provided │ ├── Amazon Linux 2023 │ ├── Ubuntu Server │ ├── Windows Server │ └── Red Hat Enterprise Linux │ ├── AWS Marketplace │ └── Pre-configured software stacks │ ├── Community AMIs │ └── Shared by AWS community │ └── Custom AMIs └── Your own configured images # Find AMIs via CLI aws ec2 describe-images \ --owners amazon \ --filters "Name=name,Values=amzn2-ami-hvm-*-x86_64-gp2" \ --query 'Images[*].[ImageId,Name,CreationDate]' \ --output table

Security Groups

Security Group = Virtual Firewall Rules: ┌─────────────────────────────────────────────────┐ │ Type │ Protocol │ Port │ Source │ ├───────────┼──────────┼──────┼──────────────────┤ │ SSH │ TCP │ 22 │ Your IP │ │ HTTP │ TCP │ 80 │ 0.0.0.0/0 │ │ HTTPS │ TCP │ 443 │ 0.0.0.0/0 │ │ Custom │ TCP │ 3000 │ 10.0.0.0/16 │ └───────────┴──────────┴──────┴──────────────────┘ Key Points: • Stateful: Return traffic automatically allowed • Default: All inbound denied, all outbound allowed • Can reference other security groups • Changes apply immediately

Key Pairs

Key Pair = SSH Authentication # Create key pair via CLI aws ec2 create-key-pair \ --key-name my-key \ --query 'KeyMaterial' \ --output text > my-key.pem # Set permissions chmod 400 my-key.pem # List key pairs aws ec2 describe-key-pairs --output table # Delete key pair aws ec2 delete-key-pair --key-name my-key # Important: # - Private key is shown ONLY at creation # - Store securely, cannot be recovered # - One key pair can be used for multiple instances

🔬 Hands-on Lab (2.5 Hours)

Lab 1: Create Key Pair and Security Group

  • Create an SSH key pair
  • Create a security group with SSH access
# Create key pair aws ec2 create-key-pair \ --key-name devops-key \ --query 'KeyMaterial' \ --output text > devops-key.pem chmod 400 devops-key.pem # Get default VPC ID VPC_ID=$(aws ec2 describe-vpcs \ --filters "Name=is-default,Values=true" \ --query 'Vpcs[0].VpcId' --output text) # Create security group SG_ID=$(aws ec2 create-security-group \ --group-name devops-sg \ --description "DevOps training security group" \ --vpc-id $VPC_ID \ --query 'GroupId' --output text) # Add SSH rule (restrict to your IP in production) aws ec2 authorize-security-group-ingress \ --group-id $SG_ID \ --protocol tcp \ --port 22 \ --cidr 0.0.0.0/0 # Add HTTP rule aws ec2 authorize-security-group-ingress \ --group-id $SG_ID \ --protocol tcp \ --port 80 \ --cidr 0.0.0.0/0 echo "Security Group ID: $SG_ID"

Lab 2: Launch EC2 Instance via Console

  • Navigate to EC2 Dashboard
  • Click "Launch Instance"
  • Configure instance settings
# Console Steps: 1. EC2 Dashboard → Launch Instance 2. Name: "devops-server" 3. AMI: Amazon Linux 2023 (Free tier eligible) 4. Instance Type: t2.micro 5. Key Pair: Select devops-key 6. Network Settings: - VPC: Default - Security Group: devops-sg 7. Storage: 8 GB gp3 (default) 8. Review and Launch # Wait for "Running" state # Note the Public IP address

Lab 3: Launch EC2 Instance via CLI

  • Find the latest Amazon Linux 2023 AMI
  • Launch instance with CLI
  • Get instance details
# Get latest Amazon Linux 2023 AMI AMI_ID=$(aws ec2 describe-images \ --owners amazon \ --filters "Name=name,Values=al2023-ami-2023*-x86_64" \ "Name=state,Values=available" \ --query 'Images | sort_by(@, &CreationDate) | [-1].ImageId' \ --output text) echo "AMI ID: $AMI_ID" # Launch instance INSTANCE_ID=$(aws ec2 run-instances \ --image-id $AMI_ID \ --instance-type t2.micro \ --key-name devops-key \ --security-group-ids $SG_ID \ --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=devops-cli-server}]' \ --query 'Instances[0].InstanceId' \ --output text) echo "Instance ID: $INSTANCE_ID" # Wait for instance to be running aws ec2 wait instance-running --instance-ids $INSTANCE_ID # Get public IP PUBLIC_IP=$(aws ec2 describe-instances \ --instance-ids $INSTANCE_ID \ --query 'Reservations[0].Instances[0].PublicIpAddress' \ --output text) echo "Public IP: $PUBLIC_IP"

Lab 4: Connect and Manage Instance

  • SSH into the instance
  • Install and run a web server
  • Stop and terminate instance
# Connect via SSH ssh -i devops-key.pem ec2-user@$PUBLIC_IP # Inside instance - install and start nginx sudo yum install -y nginx sudo systemctl start nginx sudo systemctl enable nginx # Test (from local machine) curl http://$PUBLIC_IP # Instance management aws ec2 stop-instances --instance-ids $INSTANCE_ID aws ec2 start-instances --instance-ids $INSTANCE_ID aws ec2 reboot-instances --instance-ids $INSTANCE_ID # Terminate instance (clean up) aws ec2 terminate-instances --instance-ids $INSTANCE_ID # Clean up security group and key pair aws ec2 delete-security-group --group-id $SG_ID aws ec2 delete-key-pair --key-name devops-key rm devops-key.pem

✅ Day 2 Checklist

  • Understand EC2 instance types and families
  • Can create and manage key pairs
  • Can configure security groups
  • Successfully launched EC2 instance
  • Connected via SSH
  • Can start, stop, terminate instances
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