smom-dbis-138/docs/MULTI_CLOUD_ARCHITECTURE.md

Multi-Cloud, HCI, and Hybrid Architecture

Overview

This document describes the multi-cloud, HCI (Hyper-Converged Infrastructure), and hybrid architecture for the DeFi Oracle Meta Mainnet (ChainID 138). The architecture enables deployment across:

• Multiple Cloud Providers: Azure, AWS, Google Cloud, IBM Cloud, Oracle Cloud
• On-Premises HCI: Azure Stack HCI, vSphere-based clusters
• Hybrid Environments: Combination of on-prem and cloud resources

Architecture Principles

1. Environment Abstraction

All environments are defined in a single configuration file (config/environments.yaml). Adding or removing regions, clouds, or HCI clusters requires only configuration changes, not code modifications.

2. Cloud-Agnostic Design

• Infrastructure as Code: Terraform modules for each provider
• Kubernetes-First: Standardize on Kubernetes for workload orchestration
• Abstraction Layers: Unified interfaces for networking, identity, secrets, and observability

3. Admin Region Pattern

• 1 Admin Region: Hosts CI/CD, control plane, monitoring, orchestration
• N Workload Regions: Deploy application workloads
• Flexible Location: Admin region can be on-prem, in Azure, or any cloud

Repository Structure

smom-dbis-138/
├── config/
│   └── environments.yaml          # Single source of truth for all environments
├── terraform/
│   ├── multi-cloud/
│   │   ├── main.tf                # Main orchestration
│   │   ├── providers.tf          # Multi-cloud provider configuration
│   │   ├── variables.tf          # Global variables
│   │   └── modules/
│   │       ├── azure/            # Azure infrastructure module
│   │       ├── aws/              # AWS infrastructure module
│   │       ├── gcp/              # GCP infrastructure module
│   │       ├── onprem-hci/       # On-prem HCI module
│   │       ├── azure-arc/        # Azure Arc integration
│   │       ├── service-mesh/     # Service mesh deployment
│   │       ├── secrets/          # Secrets abstraction
│   │       └── observability/   # Observability abstraction
│   └── modules/                  # Existing Azure modules (reused)
├── orchestration/
│   ├── portal/                   # Web-based orchestration UI
│   └── strategies/               # Deployment strategies (blue-green, canary)
├── k8s/                          # Kubernetes manifests
├── helm/                         # Helm charts
└── .github/workflows/            # CI/CD pipelines

Configuration File Format

The config/environments.yaml file defines all environments:

environments:
  - name: admin-azure-westus
    role: admin
    provider: azure
    type: cloud
    region: westus
    enabled: true
    components:
      - cicd
      - monitoring
      - orchestration
    infrastructure:
      kubernetes:
        provider: aks
        version: "1.28"
        node_pools:
          system:
            count: 3
            vm_size: "Standard_D4s_v3"
  # ... more environments

Deployment Flow

1. Define Environments

Edit config/environments.yaml to add/remove/modify environments.

2. Provision Infrastructure

cd terraform/multi-cloud
terraform init
terraform plan
terraform apply

3. Onboard to Azure Arc (Optional)

For hybrid management via Azure:

./scripts/arc-onboard-<environment>.sh

4. Deploy Platform Components

• Service mesh (Istio/Linkerd/Kuma)
• Secrets management
• Observability stack

5. Deploy Application Workloads

helm upgrade --install besu-network ./helm/besu-network \
  --namespace besu-network \
  --set environment=<environment-name>

Deployment Strategies

Blue-Green Deployment

Deploys new version alongside existing, then switches traffic:

./orchestration/strategies/blue-green.sh <environment> <version>

Canary Deployment

Gradually rolls out new version to a subset of traffic:

./orchestration/strategies/canary.sh <environment> <version> <percentage>

Web-Based Orchestration Portal

A Flask-based web UI provides:

• Environment Discovery: View all configured environments
• Deployment Management: Trigger deployments to any environment
• Status Monitoring: Real-time status of all environments
• Logs and Health: View deployment logs and cluster health

To run the portal:

cd orchestration/portal
pip install -r requirements.txt
python app.py

Access at: http://localhost:5000

Azure Hybrid Stack

Azure Arc Integration

Azure Arc enables:

• Unified Management: Manage Kubernetes clusters from any provider via Azure
• Policy Enforcement: Apply Azure Policies across all clusters
• GitOps: Use Azure Arc GitOps for application deployment
• Monitoring: Centralized monitoring via Azure Monitor

Azure Stack HCI

For on-premises HCI:

1. Deploy Azure Stack HCI cluster on-prem
2. Install Kubernetes (AKS on HCI or kubeadm)
3. Onboard to Azure Arc
4. Manage via Azure portal/APIs

Networking

Cross-Cloud Connectivity

Options for connecting environments:

1. Public Endpoints + mTLS: Service mesh provides secure communication
2. VPN: Site-to-site VPN between clouds
3. Private Links: Azure ExpressRoute, AWS Direct Connect, GCP Interconnect
4. Service Mesh: Istio/Linkerd for secure service-to-service communication

Network Abstraction

The architecture abstracts networking concepts:

• VPC/VNet/VLAN: Unified configuration format
• Subnets: Consistent naming and addressing
• Security Groups/NSGs/Firewalls: Provider-agnostic rules

Identity and Access

Federated Identity

• Central IdP: Azure AD, Okta, or Keycloak
• Federation: Connect to cloud provider IAM
• RBAC: Kubernetes RBAC mapped to IdP roles

Provider-Specific

• Azure: Azure AD + AKS RBAC
• AWS: IAM + EKS IRSA (IAM Roles for Service Accounts)
• GCP: GCP IAM + Workload Identity

Secrets Management

Unified Interface

Supports multiple providers:

• HashiCorp Vault: Centralized secrets (recommended for multi-cloud)
• Azure Key Vault: Per-environment or centralized
• AWS Secrets Manager: Per-environment
• GCP Secret Manager: Per-environment

Secret Sync

Secrets can be synced across providers using:

• Vault sync agents
• External Secrets Operator
• Custom sync scripts

Observability

Unified Logging

• Loki: Centralized log aggregation
• Elasticsearch: Alternative log backend
• Cloud Logging: Native cloud logging (CloudWatch, Azure Monitor, GCP Logging)

Unified Metrics

• Prometheus: Centralized metrics collection
• Grafana: Visualization and dashboards
• Cloud Metrics: Native cloud metrics (CloudWatch, Azure Monitor, GCP Monitoring)

Distributed Tracing

• Jaeger: Distributed tracing
• Zipkin: Alternative tracing backend
• Tempo: Grafana's tracing backend

Best Practices

1. State Management

• Use remote Terraform state (Terraform Cloud, S3, Azure Storage)
• Separate state per environment to avoid blast radius
• Enable state locking

2. Cost Optimization

• Tag all resources consistently
• Use spot/preemptible instances where possible
• Enable autoscaling
• Monitor costs per environment

3. Security

• Zero-trust networking
• Policy-as-code (OPA, Kyverno)
• Network policies enabled
• Pod security policies
• Secrets encryption at rest and in transit

4. Compliance

• Data residency: Deploy data stores per region
• Audit logging: Enable audit logs for all clusters
• Compliance scanning: Regular security scans

5. Testing

• Start with 2-3 environments before scaling
• Use synthetic tests to verify real usability
• Test failover scenarios
• Load test cross-cloud communication

Troubleshooting

Common Issues

1. Provider Authentication: Ensure credentials are set in environment variables
2. Network Connectivity: Verify VPN/private links are configured
3. Service Mesh: Check mTLS certificates and policies
4. Secrets: Verify secrets are accessible from all environments

Debugging

• Check Terraform state: terraform state list
• View cluster status: kubectl get nodes -A
• Check service mesh: istioctl proxy-status (if using Istio)
• View logs: Portal UI or kubectl logs

Next Steps

1. Add More Providers: IBM Cloud, Oracle Cloud modules
2. Enhanced Monitoring: Custom dashboards per environment
3. Automated Testing: Integration tests across environments
4. Cost Dashboards: Real-time cost tracking
5. Disaster Recovery: Automated failover procedures

References

• Terraform Multi-Cloud Best Practices
• Azure Arc Documentation
• Istio Multi-Cluster
• Kubernetes Multi-Cloud Patterns