Imagine this: Your company just merged with another, and suddenly, you’re managing infrastructure across AWS, Azure, and Google Cloud.
Or maybe your team wants multi-cloud resilience—so if one provider has an outage, your apps keep running elsewhere. Smart move!
But managing multiple clouds manually? That’s a nightmare. Fortunately, Terraform makes multi-cloud deployments easy, repeatable, and scalable.
In this post, we’ll cover:
- Why multi-cloud matters and when to use it.
- How to deploy to AWS, Azure, and GCP from the same Terraform config.
- Managing multi-cloud networking, authentication, and state files.
- Common challenges and how to solve them.
Let’s Terraform the clouds!
1. Why Go Multi-Cloud?
Multi-cloud isn’t for every team, but it offers big advantages when done right:
Avoid Vendor Lock-In
What if your cloud provider suddenly hikes prices or removes a key service you rely on? Multi-cloud gives you options.
Disaster Recovery & High Availability
If AWS East goes down, your app keeps running on Azure or GCP. No downtime, no panic.
Use the Best of Each Cloud
Need Azure AI services, but your data team loves AWS Redshift? Multi-cloud lets you pick the best tools.
2. Setting Up Terraform for Multi-Cloud
Terraform uses providers to manage resources in different clouds. Here’s how to set up AWS, Azure, and GCP in one Terraform configuration.
Example: Defining Multi-Cloud Providers in Terraform
provider "aws" {
region = "us-east-1"
}
provider "azurerm" {
features {}
}
provider "google" {
project = "my-gcp-project"
region = "us-central1"
}
Now, Terraform can manage resources in all three clouds!
3. Deploying Resources Across Multiple Clouds
Let’s deploy a VM in AWS, a storage account in Azure, and a database in GCP—all from one Terraform config.
# AWS: Launch an EC2 Instance
resource "aws_instance" "web" {
ami = "ami-123456"
instance_type = "t2.micro"
}
# Azure: Create a Storage Account
resource "azurerm_storage_account" "storage" {
name = "mystorage"
resource_group_name = "myRG"
location = "East US"
account_tier = "Standard"
}
# GCP: Deploy a Cloud SQL Database
resource "google_sql_database_instance" "db" {
name = "mydb"
database_version = "MYSQL_8_0"
settings {
tier = "db-f1-micro"
}
}
One terraform apply, and you’ve deployed to three clouds.
4. Managing Multi-Cloud Networking
Deploying to multiple clouds means connecting everything securely. Here’s how:
Option 1: Use a Global VPN
- AWS, Azure, and GCP all support site-to-site VPNs.
- AWS Transit Gateway, Azure Virtual WAN, and GCP Cloud Router help route traffic.
Option 2: Use a Multi-Cloud Load Balancer
- Cloudflare, F5, and Aviatrix provide global traffic management across clouds.
- DNS-based routing via AWS Route 53, Azure Traffic Manager, or GCP Cloud DNS.
5. Handling Authentication Across Clouds
Each cloud requires different authentication methods, but Terraform handles them smoothly.
How to Authenticate Terraform in Multiple Clouds
AWS: Use environment variables
export AWS_ACCESS_KEY_ID="your-key" export AWS_SECRET_ACCESS_KEY="your-secret"
Azure: Use a Service Principal
az login --service-principal -u CLIENT_ID -p CLIENT_SECRET --tenant TENANT_ID
GCP: Use a JSON key file
export GOOGLE_APPLICATION_CREDENTIALS="path-to-key.json"
Now, Terraform can authenticate with all three clouds!
6. Managing Terraform State in a Multi-Cloud World
Each cloud shouldn’t have its own Terraform state—you need one source of truth.
Best Option: Use a Remote State Backend
Example: Storing Terraform State in an Azure Storage Account
terraform {
backend "azurerm" {
resource_group_name = "myRG"
storage_account_name = "mystorage"
container_name = "tfstate"
key = "multi-cloud.tfstate"
}
}
Why It’s Cool:
- Keeps state consistent across all clouds.
- Supports state locking to prevent conflicts.
- Enables collaboration for multi-cloud teams.
7. Challenges & How to Solve Them
| Challenge | Solution |
|---|---|
| Different APIs & Services | Use Terraform modules to abstract cloud differences. |
| Security Complexity | Centralize authentication (e.g., HashiCorp Vault, AWS IAM Roles). |
| Networking Headaches | Use a multi-cloud VPN or load balancer. |
| State Management | Use a remote backend like Azure Storage, AWS S3, or Terraform Cloud. |
Pro Tip: Keep your Terraform code modular so different clouds can be managed independently!
8. Should You Go Multi-Cloud?
Multi-cloud is powerful, but it’s not always necessary. Here’s when to use it—and when to avoid it.
Go Multi-Cloud If:
- You need redundancy across multiple providers.
- You want to avoid vendor lock-in.
- You need specific services from different clouds.
Stick to One Cloud If:
- You don’t have a dedicated DevOps team.
- Your workloads don’t need global redundancy.
- Your team is new to Terraform—master single-cloud first.
The sweet spot? Start with one cloud, then expand to multi-cloud when it makes sense.
Wrapping Up
Terraform makes multi-cloud deployments possible and manageable—but only if you plan properly.
Quick Recap:
- Use Terraform providers to manage AWS, Azure, and GCP from one config.
- Connect multi-cloud networking with VPNs or load balancers.
- Store Terraform state in a remote backend for consistency.
- Handle authentication across clouds with environment variables or service principals.
- Start simple, then expand multi-cloud as needed.
Now, go Terraform across the clouds!
What’s Next?
Deploying across multiple clouds is great, but what if your infrastructure could scale and adapt dynamically? In the next post, “Dynamic Infrastructure with Terraform,” we’ll explore how to create auto-scaling, self-healing, and event-driven infrastructure using Terraform.