GitOps and Terraform together create a robust framework for managing infrastructure as code with automated, version-controlled, and collaborative workflows. By combining these approaches, organizations can achieve streamlined infrastructure management, improved consistency, and enhanced reliability of deployments across various environments.
Infrastructure management has become a critical aspect of software development. Cloud infrastructure needs to be agile and dependable. Two powerful concepts have emerged to meet these demands: GitOps and Infrastructure-as-Code. When combined, these approaches create a robust framework for managing infrastructure as code. Terraform is an open source Infrastructure as Code tool created by HashiCorp. It allows developers and operations teams to define and provision infrastructure using a declarative language.
What Is Terraform
Terraform is an infrastructure-as-code tool developed by HashiCorp. It allows you to build, change, manage, and version your infrastructure through human-readable configuration files. It offers a unified way to define, provision, and manage resources across various cloud providers and services using Hashicorp Configuration Language syntax, which is easy to learn and read.
Because Terraform lets you describe your infrastructure in code files, this enables version control, change tracking, collaboration, and repeatability when provisioning infrastructure, ensuring consistent deployments across environments and avoiding manual configuration errors.
Terraform supports infrastructure management across multiple cloud providers and on-premises data centers through plugins, which convert Terraform configurations into specific API calls for each platform. Terraform uses a declarative approach. You specify the desired end state, and the tools handle the implementation details.
Terraform is an open source Infrastructure as Code tool created by HashiCorp. It allows developers and operations teams to define and provision infrastructure using a declarative language.
What Is GitOps
GitOps is an operational framework that takes DevOps best practices used for application development and applies them to infrastructure automation. At its core, GitOps uses Git repositories as the single source of truth for declarative infrastructure and applications. This approach leverages Git's version control capabilities to manage infrastructure changes, providing a clear audit trail and facilitating collaboration among team members.
GitOps is the practice of using Git as the single source of truth for your infrastructure. Every change goes through a pull request, every deployment is triggered by a Git merge, and the actual state of your infrastructure always matches what is in the repository.
In a GitOps workflow, any change to the infrastructure is made through a Git repository. Automated processes then sync these changes with the actual infrastructure, ensuring that the deployed state always matches the desired state defined in the repository. This method enhances transparency, improves security, and streamlines the change management process.
The term GitOps was first coined by Weaveworks, and its key concept is using a Git repository to store the environment state that you want.
Why Combine GitOps with Terraform
Combining Terraform with GitOps creates a powerful synergy for infrastructure management.
- Declarative Nature: Both GitOps and Terraform embrace a declarative approach. You specify the desired end state, and the tools handle the implementation details.
- Version Control: Terraform configurations can be easily stored in Git repositories, aligning perfectly with GitOps principles.
- Automation Friendly: Terraform's command-line interface makes it ideal for integration with CI/CD pipelines, a key component of GitOps workflows.
- State Management: Terraform's state files provide a clear picture of the current infrastructure, which can be compared against the desired state defined in Git.
- Modularity: Terraform's module system allows for reusable, composable infrastructure components, making it easier to manage complex setups through GitOps practices.
By leveraging Terraform within a GitOps framework, organizations can achieve a high degree of automation, consistency, and traceability in their infrastructure management processes.
It enables teams to apply software development best practices to infrastructure management, resulting in more reliable, secure, and agile infrastructure deployments.
Core GitOps Principles Applied to Terraform
The four GitOps principles applied to Terraform provide a clear operational model.
| Principle | Terraform Application |
|---|---|
| Declarative | Infrastructure is defined in Terraform HCL files |
| Versioned and immutable | All changes are committed to Git with full history |
| Pulled automatically | The CI/CD system watches Git and applies changes |
| Continuously reconciled | Drift is detected and corrected automatically |
Terraform is a natural fit for GitOps because it already defines infrastructure declaratively in code. The challenge is building the automation that closes the loop between Git and your actual infrastructure.
The GitOps Workflow for Terraform
The GitOps workflow for Terraform follows a pull-based, review-driven process.
Developer creates feature branch
|
v
Developer modifies Terraform files
|
v
Developer opens pull request
|
v
CI automatically runs: fmt, validate, plan
|
v
Team reviews code + plan output
|
v
PR is approved and merged to main
|
v
CI automatically runs: terraform apply
|
v
Scheduled job detects drift and auto-reconciles
The key difference from regular CI/CD is the last step: continuous reconciliation.
This tutorial explains how to manage infrastructure as code with Terraform and Cloud Build using the popular GitOps methodology. Terraform is a HashiCorp tool that enables you to predictably create, change, and improve your cloud infrastructure by using code.
Four Step Process to Implement GitOps with Terraform
A four-step process to implement GitOps with Terraform enables teams to streamline their workflows, improve consistency, and enhance the reliability of their infrastructure deployments across various environments.
- Define infrastructure declaratively in Terraform HCL and store it in Git
- Enforce review through pull requests with automated plan validation
- Automate apply on merge with CI/CD pipelines
- Reconcile continuously to detect and correct drift
This article outlines a four-step process to implement GitOps with Terraform, enabling teams to streamline their workflows, improve consistency, and enhance the reliability of their infrastructure deployments across various environments.
Pipeline Automation and CI/CD Integration
The final step involves setting up a CI/CD pipeline that will automatically apply your Terraform changes to your infrastructure. This pipeline is the core of your GitOps workflow, ensuring that any changes pushed to your Git repository are reflected in your actual infrastructure.
Your pipeline should include steps to checkout the latest code, initialize Terraform, generate a plan, and apply changes. Pipelines can seem counter-intuitive for a GitOps flow. It's common to ask, "But shouldn't we just do a pull request and apply the approved change?" However, pipeline automation can help inform that pull request.
A typical pipeline stage can be expressed as:
yaml
steps:
- name: checkout
uses: actions/checkout@v4
- name: terraform init
run: terraform init -backend-config=...
- name: terraform fmt
run: terraform fmt -check
- name: terraform validate
run: terraform validate
- name: terraform plan
run: terraform plan -out=tfplan
- name: terraform apply
if: github.ref == 'refs/heads/main'
run: terraform apply tfplan
Automated processes then sync these changes with the actual infrastructure, ensuring that the deployed state always matches the desired state defined in the repository.
State Management and Drift Reconciliation
Terraform's state files provide a clear picture of the current infrastructure, which can be compared against the desired state defined in Git.
Continuously reconciled means drift is detected and corrected automatically. A scheduled job can run terraform plan on a regular interval and report or remediate differences between the actual cloud resources and the Git defined configuration.
State Management considerations for GitOps:
- Store remote state in a secure backend such as S3, GCS, or Azure Blob
- Enable state locking to prevent concurrent applies
- Keep state separate from Git, but reference it from Git defined pipelines
- Use workspaces or separate directories per environment
Terraform with Cloud Build and GitOps
This tutorial explains how to manage infrastructure as code with Terraform and Cloud Build using the popular GitOps methodology. You use Cloud Build, a Google Cloud continuous integration service, to automatically apply Terraform manifests to your environment.
To demonstrate how this tutorial applies GitOps practices for managing Terraform executions, consider the following architecture diagram. Note that it uses GitHub branches to represent actual environments. These environments are defined by Virtual Private Cloud networks into a Google Cloud project.
The process starts when you push Terraform code to either the dev or prod branch.
The article assumes you are familiar with Google Cloud, Linux, and GitHub. The State of DevOps reports identified capabilities that drive software delivery performance.
Practical Implementation Considerations
In this article, we will examine how to use Terraform with GitOps, explaining both and their benefits. We will then move on to some practical examples showing how to implement and configure Terraform to create cloud infrastructure in Azure with an integrated git repository and pipeline.
If you're new to Terraform or unfamiliar with GitOps, this article will get you up and running.
Terraform supports infrastructure management across multiple cloud providers and on-premises data centers through plugins.
Leverage GitOps For Your Terraform or OpenTofu. As DevOps has taken hold in the software development, infrastructure management has become a critical aspect of software development. We need cloud infrastructure to be agile and dependable.
Harness is sponsor of the OpenTofu project and believes you should use OpenTofu over Terraform.
| Feature | Terraform | OpenTofu |
|---|---|---|
| License model | Commercial backed | Open source |
| Declarative IaC | Yes | Yes |
| GitOps compatible | Yes | Yes |
| HCL support | Yes | Yes |
Both tools embrace declarative infrastructure and integrate with GitOps workflows.
Benefits of GitOps Terraform
- Declarative Nature: Both GitOps and Terraform embrace a declarative approach. You specify the desired end state, and the tools handle the implementation details.
- Version Control: Terraform configurations can be easily stored in Git repositories, aligning perfectly with GitOps principles.
- Automation Friendly: Terraform's command-line interface makes it ideal for integration with CI/CD pipelines, a key component of GitOps workflows.
- State Management: Terraform's state files provide a clear picture of the current infrastructure, which can be compared against the desired state defined in Git.
- Modularity: Terraform's module system allows for reusable, composable infrastructure components, making it easier to manage complex setups through GitOps practices.
By leveraging Terraform within a GitOps framework, organizations can achieve a high degree of automation, consistency, and traceability in their infrastructure management processes.
Conclusion
GitOps with Terraform delivers automated, version-controlled, and collaborative infrastructure management by treating Git as the single source of truth and using Terraform's declarative language to define desired state. The four core principles of declarative definition, versioned immutability, automated pull-based application, and continuous reconciliation form the foundation of a reliable workflow.
The practical workflow of branch, modify, pull request, automated fmt validate plan, review, merge, automated apply, and scheduled drift reconciliation ensures every change is audited, reviewed, and reproducible. Pipeline automation bridges the gap between approval and enforcement, while Terraform state management provides visibility into current infrastructure for comparison against Git.
Organizations adopting this combination benefit from enhanced transparency, improved security, streamlined change management, and consistent deployments across dev and prod environments. The integration with services such as Cloud Build for Google Cloud or pipelines for Azure and AWS demonstrates how the pattern scales across providers and teams.
As you embark on your GitOps journey with Terraform, remember that the key to success lies in embracing the principles of automation, version control, and continuous improvement. With these practices in place, you'll be well-equipped to handle the challenges of modern infrastructure management in an increasingly complex technological landscape.