Cloud Engineering / DevOps

Terraform for AWS and GCP: A Practical Guide to Multi-Cloud Infrastructure Automation

Learn how Infrastructure as Code can help teams provision, manage, and standardize cloud resources across Amazon Web Services and Google Cloud Platform.

TERRAFORM · AWS · GCP · IaC

Introduction

Cloud infrastructure becomes harder to manage as applications, environments, and deployment requirements grow. Creating resources manually can lead to configuration inconsistencies, repetitive work, and avoidable mistakes.

Infrastructure as Code (IaC) offers a more structured approach. Instead of configuring every resource manually, engineers define infrastructure in files that can be reviewed, version-controlled, and reused.

Terraform is one tool that supports this approach across multiple cloud providers, including AWS and Google Cloud Platform (GCP).

Why use Terraform?

⚙️

Automation

Define infrastructure in code and reduce repetitive manual configuration.

🔁

Consistency

Reuse configurations to help standardize development, testing, and production environments.

☁️

Multi-cloud

Manage supported resources across different cloud providers using their respective providers.

What is Terraform?

Terraform is an Infrastructure as Code tool that lets you describe the desired state of your infrastructure using declarative configuration files. It compares the configuration with the current state and proposes changes through an execution plan.

Terraform configurations commonly use HashiCorp Configuration Language (HCL). They can define resources, reference existing infrastructure, use variables, and organize reusable modules.

Example: Configure AWS and GCP providers

The following example shows how a Terraform configuration can declare both providers. It is a starting point, not a complete deployment: it creates no cloud resources by itself.

main.tf

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
    }
    google = {
      source  = "hashicorp/google"
    }
  }
}

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

provider "google" {
  project = var.gcp_project_id
  region  = "us-central1"
}

variable "gcp_project_id" {
  type        = string
  description = "Your Google Cloud project ID"
}

Before running this configuration: select and pin suitable provider versions, configure valid AWS and Google Cloud credentials, and verify that the GCP project exists. Never place secret keys directly in configuration files.

A practical Terraform workflow

STEP 01

Write the configuration

Define providers, resources, variables, and reusable modules in Terraform files.

STEP 02

Initialize the project

Run terraform init to initialize the working directory and install the required providers.

STEP 03

Validate and review

Use terraform validate and terraform plan to check configuration and inspect proposed changes.

STEP 04

Apply reviewed changes

Run terraform apply only after reviewing the plan and confirming that the changes are appropriate.

Terraform best practices

✓ Store configurations in version control.

✓ Use reusable modules and consistent naming conventions.

✓ Protect Terraform state and restrict access to it.

✓ Keep credentials out of source code and use secure authentication.

✓ Review plans before applying infrastructure changes.

✓ Use least-privilege permissions, monitoring, and appropriate approval workflows.

Conclusion

Terraform can make multi-cloud infrastructure management more repeatable, reviewable, and maintainable. Success depends on thoughtful module design, secure state management, proper access controls, and disciplined change reviews.

Whether you're working with AWS, GCP, or both, Infrastructure as Code provides a foundation for more consistent cloud operations and automation.

ABOUT THE AUTHOR

Lokesh Katagani

Lead DevOps Engineer focused on cloud infrastructure, Terraform, CI/CD, automation, AWS, and Google Cloud Platform.

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Topics: Terraform, AWS, Google Cloud Platform, DevOps, Infrastructure as Code, CI/CD, Cloud Automation.