Multi-Cluster Istio Patterns

This repository provides Terraform configurations for deploying multi-cluster Istio on AWS using various networking and certificate management patterns.

📁 Available Patterns

• internet: Cross-cluster communication over internet-facing gateways.
• peering: Communication via AWS VPC peering.
• peering-cert-manager: VPC peering with Vault + cert-manager-based certificate management.

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🔧 Prerequisites

• Terraform >= 1.3
• AWS CLI
• kubectl
• Helm
• AWS credentials (via aws configure or environment variables)

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🚀 Usage

Each pattern folder includes a Makefile to simplify usage.

Common Make Targets

make init        # Initialize Terraform
make plan        # Show Terraform plan
make apply       # Apply infrastructure
make destroy     # Tear down resources
make validate    # Validate configuration
make fmt         # Format Terraform code
make check-sync  # Verify cross-cluster connectivity (if supported)

📦 Pattern-Specific Instructions

internet

Uses internet-facing Istio east-west gateways with self-managed CA.

cd multi-network/internet
make init apply

peering

Sets up private east-west communication using AWS VPC peering.

cd multi-network/peering
make init apply

peering-cert-manager

Uses Vault and cert-manager to issue Istio certificates.

cd multi-network/peering-cert-manager
make deploy

This script bootstraps the infrastructure and configures Vault.

✅ Post-Deployment Check

Run the sync script to validate application connectivity across clusters:

make check-sync

📎 Notes

• Each cluster deploys a sample helloworld and sleep app.
• Secrets, remote Kubeconfigs, and gateways are auto-managed by Terraform and Helm.