Multi-Domain Infrastructure as Code (IaC): Terraform Beyond Cloud

Introduction

Infrastructure as Code (IaC) has revolutionized how we deploy and manage infrastructure, but most organizations still limit it to cloud-native automation — provisioning EC2 instances, setting up Kubernetes clusters, or configuring VPCs. However, today’s enterprise infrastructure spans data centers, telecom networks, edge compute nodes, hybrid cloud platforms, and even physical routers.

In this extended guide, we explore the evolving capabilities of multi-domain IaC — how tools like Terraform, Pulumi, and Crossplane are enabling infrastructure provisioning and governance across public cloud, on-prem, telco, and edge environments.

What Is Multi-Domain IaC?

Multi-domain IaC means using a single codebase or orchestration workflow to manage:

• Cloud workloads (AWS, Azure, GCP)

• On-prem infrastructure (VMware, bare-metal, Cisco/Juniper)

• Edge compute devices (IoT, MEC)

• Telco environments (5G infrastructure, SD-WAN)

• Container orchestration platforms (K8s, EKS, OpenShift)

This convergence is essential for large enterprises embracing hybrid and distributed architectures.

The Evolution of IaC

Terraform: Beyond Cloud Provisioning

Terraform by HashiCorp is the world’s most widely adopted IaC tool, supporting over 2,500 providers.

While traditionally used to manage cloud services, Terraform now supports:

On-Prem Providers

• VMware vSphere

• Nutanix

• Cisco UCS Manager

• Redfish for bare-metal provisioning

Network & Telco Providers

• Cisco NSO

• Juniper Contrail

• Palo Alto PANOS

• F5 BIG-IP

Hybrid/Interconnect Providers

• Equinix Metal

• PacketFabric

• Megaport

Example Use Case: Hybrid Cloud IaC

A global bank uses Terraform to:

1. Provision a Kubernetes cluster on AWS.

2. Deploy a firewall configuration via Palo Alto PANOS provider.

3. Spin up an Equinix Metal bare-metal edge server.

4. Configure VLAN trunking between cloud VPC and physical DC.

5. Push GitOps policies into ArgoCD for workload deployment.

All with a single Terraform plan.

Pulumi vs Terraform: A Developer’s Choice

While Terraform uses HCL (HashiCorp Configuration Language), Pulumi supports general-purpose programming languages (TypeScript, Python, Go, .NET), appealing to app developers.

Capability	Terraform	Pulumi
Language	HCL	TypeScript, Python, etc.
Multi-Cloud
Network IaC	(via providers)	Limited
Edge Support	Moderate	Moderate
GitOps Integration	CLI-based	Native SDK integration

Pulumi is preferred where infrastructure is closely coupled with app logic, such as serverless or microservices.

Managing On-Prem & Network Infrastructure as Code

1. VMware + Terraform

• Spin up VMs, define resource pools, configure network interfaces

• Use alongside vRA for governance

• Terraform vSphere provider supports tagging, cloning, and snapshotting

2. Cisco NSO + Terraform

• Automate Layer 2/3 network configuration

• Use YANG models to expose device parameters

• Ideal for network service chains and SD-WAN

3. Juniper Contrail + Terraform

• Provision virtual routers, firewalls, VXLANs

• Integrate with telco cloud and 5G packet cores

IaC for Edge Compute

Edge is becoming the next frontier for infrastructure automation:

• Low latency demands

• Data locality regulations

• Autonomous system requirements (e.g., factories, drones)

Tooling:

• HashiCorp Nomad + Terraform for edge workloads

• K3s (lightweight Kubernetes) + GitOps + IaC

• Raspberry Pi / Nvidia Jetson provisioned via Redfish + Terraform

Challenges:

• Network instability at edge locations

• No centralized control plane

• Limited bootstrapping options

Solutions:

• Use immutable infrastructure models

• Embrace event-driven provisioning (e.g., via MQTT triggers)

Multi-Cloud + Hybrid Orchestration

As enterprises adopt multiple cloud providers, IaC becomes a unifying layer to:

• Avoid cloud lock-in

• Standardize governance and compliance

• Integrate on-prem systems (e.g., SAP, Oracle Exadata)

Crossplane Example:

• Treat infrastructure as Kubernetes Custom Resources

• Compose infrastructure + app deployment in one YAML spec

• Compatible with GitOps tools like FluxCD, ArgoCD

GitOps + IaC = Continuous Delivery for Infra

IaC is foundational for GitOps — managing infrastructure state via version-controlled Git repositories.

Benefits:

• Rollback-friendly

• Auditable

• Peer-reviewed (via PRs)

• Fully automated

Key Tools:

• ArgoCD: Declarative GitOps engine

• FluxCD: Lightweight GitOps for Kubernetes

• Atlantis / Terraform Cloud: Git-integrated IaC pipelines

Policy-as-Code & Compliance

As infra becomes code, security must also be codified.

Use Sentinel (HashiCorp) or Open Policy Agent (OPA) to:

• Prevent unencrypted storage volumes

• Enforce tagging standards

• Block use of public subnets

Policies are evaluated during:

• terraform plan

• GitOps sync events

• CICD pre-merge checks

Secrets & Identity Management in IaC

Secrets like API keys and SSH keys must never be hardcoded.

Best Practices:

• Use HashiCorp Vault to inject secrets dynamically

• Integrate AWS Secrets Manager, Azure Key Vault, or CyberArk

• Rotate secrets via automation

• Apply RBAC policies on who can access state files

Event-Driven Infrastructure (Future Outlook)

The next wave of IaC will be event-driven:

• Infra provisions based on business events (e.g., a new tenant signs up)

• APIs trigger serverless or IaC modules dynamically

• Tools like Crossplane + Knative and Terraform Cloud webhooks are early enablers

Emerging Use Cases in Multi-Domain IaC

Business Impact

Multi-domain IaC enables:

• 80% reduction in manual provisioning time

• 60–70% increase in consistency of deployments

• Stronger compliance alignment (SOC 2, ISO 27001)

• Significant OpEx savings via unified automation

Challenges

1. State Management
   Multi-provider state handling can be tricky; requires state backends like S3, Consul, or Terraform Cloud.

2. Skill Gaps
   Network and cloud teams often operate in silos. Upskilling is required.

3. Secrets Sprawl
   Use centralized tools to manage credentials securely.

4. Platform Drift
   Use drift detection tools like Driftctl or CloudQuery.

Skills & Certifications

Skills:

• Terraform / Pulumi / Crossplane proficiency

• GitOps workflows

• Cloud + On-prem hybrid architecture

• Security & compliance-aware engineering

Certifications:

• HashiCorp Certified: Terraform Associate

• Kubernetes + CKA

• Azure/Google/AWS DevOps Engineer Professional

Call to Action

Infrastructure is no longer static — and it’s no longer just “cloud.”
The future of IT is hybrid, distributed, and dynamic. Multi-domain IaC isn’t just a nice-to-have; it’s a core competency for digital-first organizations.

Embrace IaC beyond VMs. Think networks, edge, telco, bare metal.

Start your multi-domain IaC journey today with tutorials, architecture templates, and vendor reviews at www.techinfrahub.com

Or reach out to our data center specialists for a free consultation.

 Contact Us: info@techinfrahub.com