☁️ Cloud Migration Skill

Migration Strategies (6 Rs)

Strategy	Description	Use When
Rehost	Lift-and-shift	Quick migration, no changes
Replatform	Minor optimizations	Need some cloud benefits
Repurchase	Switch to SaaS	Commercial alternative exists
Refactor	Full redesign	Need cloud-native features
Retire	Decommission	App no longer needed
Retain	Keep on-premises	Not ready to migrate

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AWS Migration

Common Services Mapping

On-Premises	AWS Equivalent
Web Server	EC2, ECS, Lambda
Database	RDS, DynamoDB, Aurora
File Storage	S3, EFS
Load Balancer	ELB, ALB
DNS	Route 53
CDN	CloudFront

Infrastructure as Code (Terraform)

# AWS EC2 Instance
resource "aws_instance" "web" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
  
  tags = {
    Name = "web-server"
    Environment = "production"
  }
}

# S3 Bucket
resource "aws_s3_bucket" "assets" {
  bucket = "my-app-assets"
}

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GCP Migration

Services Mapping

Concept	GCP Service
Compute	Compute Engine, Cloud Run
Database	Cloud SQL, Firestore
Storage	Cloud Storage
Serverless	Cloud Functions
Kubernetes	GKE

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Azure Migration

Services Mapping

Concept	Azure Service
Compute	Virtual Machines, App Service
Database	Azure SQL, Cosmos DB
Storage	Blob Storage
Serverless	Azure Functions
Kubernetes	AKS

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Migration Checklist

Pre-Migration

• Inventory all applications
• Assess dependencies
• Choose migration strategy
• Estimate costs (TCO calculator)
• Plan network architecture
• Security compliance review

During Migration

• Set up landing zone
• Configure networking (VPC, VPN)
• Migrate databases
• Migrate applications
• Update DNS records
• Test thoroughly

Post-Migration

• Monitor performance
• Optimize costs
• Implement auto-scaling
• Set up backups
• Document architecture