Multi-Cloud Failover

Automatic failover system between AWS and Azure using Cloudflare DNS health monitoring. Built with Terraform and automated via GitHub Actions.

Overview

This project implements high-availability web hosting across two cloud providers. AWS S3 + CloudFront serves traffic under normal conditions. When AWS becomes unavailable, Cloudflare automatically redirects users to Azure Blob Storage based on health check results.

Architecture

Primary origin: AWS S3 bucket behind CloudFront CDN Secondary origin: Azure Blob Storage static website Failover logic: Cloudflare Load Balancer with HTTP health checks Monitoring: CloudWatch (AWS) and Azure Monitor Deployment: GitHub Actions workflow

Components

AWS Module

• S3 bucket with website configuration
• CloudFront distribution with Origin Access Identity
• CloudWatch alarms for 5xx errors and traffic drops

Azure Module

• Storage account with static website enabled
• LRS replication for cost optimization
• Azure Monitor alerts for availability

Cloudflare Module

• Health check monitor querying /health.json
• Load balancer pools for each cloud provider
• Automatic failover after 2 failed checks

Files

terraform/
  modules/aws/         S3, CloudFront, monitoring
  modules/azure/       Blob storage, monitoring
  modules/cloudflare/  DNS, health checks
  main.tf              Provider configs, module calls
  variables.tf         Input variables
  outputs.tf           Resource identifiers

website/
  index.html           Dashboard showing active provider
  health.json          Health check response

.github/workflows/
  deploy.yml           Terraform apply + S3/Azure sync

Security

S3 bucket blocks public access. CloudFront Origin Access Identity enforces CDN-only access. HTTPS enforced on all endpoints. Content Security Policy headers prevent XSS. Azure Storage requires TLS 1.2+.

Credits

Website design by Claude Code.