Terraform: How to work with multiple different cloud providers

Overview

Welcome to this comprehensive guide on harnessing the power of Terraform to orchestrate infrastructure across multiple cloud providers. Terraform, an open-source Infrastructure as Code (IaC) tool developed by HashiCorp, enables you to define both cloud and on-premises resources in human-readable configuration files that can be versioned, reused, and shared.

While Terraform’s ability to manage resources across various cloud providers is one of its most powerful features, it can also introduce complexity. This guide aims to simplify these complexities by walking you through multiple examples, from basic to advanced, demonstrating how to efficiently utilize Terraform with different cloud platforms.

Getting Started

Before diving into working with multiple cloud providers, it’s essential to understand the basics of Terraform. Terraform uses a declarative configuration language known as HashiCorp Configuration Language (HCL) to describe the desired state of your cloud infrastructure.

Installation of Terraform involves downloading the Terraform binary appropriate for your operating system from the Terraform website and setting it up in your system’s PATH. Once installed, you can verify the installation by running terraform version in your terminal.

Example 1: Basic Configuration with AWS

Let’s start by configuring Terraform to work with AWS:

provider "aws" {
  region = "us-east-1"
}

resource "aws_s3_bucket" "example" {
  bucket = "my-unique-bucket-name-12345"
  acl    = "private"
}

This example demonstrates how to declare a provider and define a resource (S3 bucket in this case) within AWS. After running terraform init to initialize the project and downloading the necessary plugins, executing terraform apply will create the S3 bucket.

Example 2: Adding a Google Cloud Platform Resource

Next, let’s integrate a Google Cloud Platform (GCP) resource:

provider "google" {
  credentials = file("path/to/your/service-account-file.json")
  project     = "your-project-id"
  region      = "us-central1"
}

resource "google_storage_bucket" "example" {
  name          = "a-unique-bucket-name-12345"
  location      = "US"
  force_destroy = true
}

This configuration illustrates how to incorporate a GCP resource, in this scenario, a Cloud Storage bucket. The process is similar to AWS: define the provider, followed by the resource, and execute terraform apply.

Example 3: Azure Resource Configuration

Finally, let’s add an Azure resource to the mix:

provider "azurerm" {
  features {}
}

resource "azurerm_resource_group" "example" {
  name     = "MyResourceGroup"
  location = "East US"
}

Through this example, you’re introduced to Azure RM provider configuration and resource group creation. Similar to the previous examples, execution involves terraform init and terraform apply.

Advanced Configuration: Orchestrating Resources Across Cloud Providers

Now that we’ve covered basic configurations for individual cloud providers, let’s explore an advanced setup that spans across these providers.

One of Terraform’s strengths is its ability to manage complex cloud architectures seamlessly. The following snippet demonstrates how to orchestrate an infrastructure sprawl across AWS, GCP, and Azure:

# AWS S3 bucket
resource "aws_s3_bucket" "example" {
  bucket = "my-unique-bucket-name-12345"
  acl    = "private"
}

# Google Cloud Storage bucket
resource "google_storage_bucket" "example_gcp" {
  name = "a-unique-bucket-name-gcp-12345"
  location = "US"
}

# Azure Resource Group
resource "azurerm_resource_group" "example_az" {
  name     = "MyResourceGroup"
  location = "East US"
}

This configuration illustrates coordinating resources across AWS, GCP, and Azure. Here, the key is to manage each provider’s configuration separately but within the same Terraform configuration file, allowing resource orchestration across cloud environments.

Best Practices for Terraform with Multiple Cloud Providers

Working with multiple cloud providers involves juggling different provider specifications, authentication methods, and resources types. Here are several best practices to help streamline this process:

• Use version control to manage your Terraform configurations.
• Isolate different cloud provider resources into modules for better organization and reusability.
• Employ workspaces for managing different environments (e.g., development, testing, production) across your cloud infrastructure.
• Explicitly define provider versions to avoid compatibility issues with Terraform updates.

Conclusion

Terraform’s capability to abstract the complexity of managing resources across multiple cloud providers simplifies the deployment and management of multi-cloud environments. By understanding and applying the foundational and advanced principles shared in this guide, you’re well on your way to becoming proficient in multi-cloud infrastructure automation using Terraform.