OpenTofu: The Open-Source Alternative to Terraform

Infrastructure as Code (IaC) has revolutionized IT infrastructure management, with HashiCorp’s Terraform leading the way for many years. However, when HashiCorp introduced licensing restrictions on Terraform, it left many organizations questioning the future of their open-source infrastructure tooling. 

Enter OpenTofu: a community-driven fork of Terraform that's rapidly gaining traction among developers and operations teams alike.

Born out of a desire to preserve the open-source ethos, OpenTofu is more than just a Terraform clone. It represents a philosophical shift in how we approach infrastructure management tools. In this post, we'll dive deep into OpenTofu, unpack its origins, explore its key features, and see how it stacks up against its well-established predecessor.

Whether you're a seasoned Terraform user or new to the world of IaC, understanding OpenTofu is crucial as we navigate the ever-evolving terrain of cloud infrastructure management. So, let's roll up our sleeves and get to know this promising new player in the DevOps toolkit.

What is OpenTofu?

OpenTofu is an open-source infrastructure as code tool that allows users to define and provision data center infrastructure using a declarative configuration language. As a fork of HashiCorp's Terraform, it was created to ensure the continued availability of a fully open-source option for infrastructure management.

At its core, OpenTofu enables developers and operations teams to manage complex infrastructure setups through code, bringing software development practices to infrastructure management. This approach, known as Infrastructure as Code (IaC), facilitates version control, code review, and automated testing for infrastructure changes.

OpenTofu supports a wide array of service providers and can manage both cloud and on-premises resources. From spinning up virtual machines to configuring networking rules, it provides a unified workflow for provisioning and managing infrastructure across different platforms.

Why OpenTofu Now and How It Differs from Terraform

OpenTofu was born out of the open-source community’s response to HashiCorp’s decision to change Terraform’s license from the Mozilla Public License v2.0 (MPL v2.0) to the more restrictive Business Source License (BSL). This shift raised concerns about the long-term accessibility and open-source future of Terraform, prompting the need for an alternative that would uphold open-source principles and empower the community to drive the tool’s direction.

Here’s how OpenTofu differs from Terraform and why it represents a significant shift in the Infrastructure as Code (IaC) landscape:

Licensing:

OpenTofu remains fully open-source under the MPL v2.0 license, ensuring unrestricted access to its code and the freedom for users to modify and distribute it. In contrast, Terraform now operates under the BSL, which imposes limitations on its use and restricts open development as a source-available licence.

Governance:

OpenTofu is governed by the community through the Linux Foundation, emphasizing a decentralized and collaborative approach. This means development decisions, feature requests, and bug fixes are driven by the broader community. Terraform, on the other hand, remains under the control of HashiCorp, with development decisions made centrally by the company.

Feature Parity and Divergence:

While OpenTofu began as a fork of Terraform and maintains feature parity for now, the two tools are expected to diverge over time. OpenTofu will evolve based on community priorities and needs, while Terraform’s feature set will likely be influenced by HashiCorp’s commercial goals. This divergence may lead to OpenTofu gaining new features or adopting changes faster in areas prioritized by its users.

Provider Ecosystem:

Both OpenTofu and Terraform can utilize the existing ecosystem of providers to manage infrastructure across multiple platforms. However, differences may arise in how quickly new providers are supported. OpenTofu, driven by community contributions, may focus on rapid provider development for cloud and on-premises systems based on user demand, while Terraform’s provider updates will follow HashiCorp’s priorities.

Development Pace:

As a community-driven project, OpenTofu is likely to see a faster pace of development in areas that matter most to its users. This could include bug fixes, new features, and provider support, with the community able to directly influence the tool’s roadmap. Terraform’s development, meanwhile, will be steered by HashiCorp’s internal timelines and enterprise focus.

Enterprise Features:

OpenTofu aims to keep all features fully open-source, making it a cost-effective solution for teams of any size. In contrast, Terraform separates certain advanced features—such as governance, policy enforcement, and collaboration—into its enterprise offering, which is only available under commercial licensing.

OpenTofu stands out as more than just a fork of Terraform; it represents a philosophical shift toward community empowerment, open governance, and unrestricted access. By combining these differences with its commitment to open-source values, OpenTofu provides a stable, innovative, and flexible alternative for organizations looking to maintain control over their infrastructure as code tools without compromising on features or flexibility.

History of OpenTofu

The history of OpenTofu is closely intertwined with that of Terraform:

Since its inception, OpenTofu has gained support from major tech companies and cloud providers, indicating strong interest in maintaining an open-source IaC solution.

Why Use OpenTofu and What Does It Offer?

OpenTofu is more than just an open-source alternative to Terraform—it combines the power of a community-driven project with a robust feature set that makes it a compelling choice for managing infrastructure as code. Here’s why OpenTofu stands out and the key features it offers:

Open-Source Commitment & Community Governance:

As a fully open-source tool under the MPL v2.0 license, OpenTofu ensures unrestricted access to its codebase. Managed by the Linux Foundation, it benefits from diverse contributions, making it a tool shaped by its community’s needs. This open governance model also drives faster innovation and development, responding directly to user demands.

Compatibility & Flexibility:

OpenTofu maintains full compatibility with existing Terraform configurations and providers, making it an easy transition for users already familiar with Terraform. Its flexibility allows for extensive customization and integration with other tools, offering broad support for cloud and on-premises infrastructure.

Declarative Infrastructure as Code:

Like Terraform, OpenTofu uses the HashiCorp Configuration Language (HCL) for declarative infrastructure management. This allows users to define their infrastructure in a way that’s easy to read and understand, while also being compatible with version control systems for change tracking.

Comprehensive State Management:

OpenTofu keeps track of infrastructure changes with a state file, ensuring you always have an accurate representation of your deployed resources. Features like state locking prevent concurrent modifications, maintaining consistency and preventing accidental overwrites.

Plan and Apply Workflow:

OpenTofu allows users to generate a detailed execution plan (opentofu plan) before applying any changes. This helps prevent unexpected infrastructure modifications by giving teams full visibility into what changes will be made before they are applied.

Resource Graph:

OpenTofu builds a dependency graph of your resources, allowing it to determine the correct order for creating, updating, or deleting them. This automatic ordering ensures efficient infrastructure provisioning.

Modular Infrastructure & Reusability:

OpenTofu supports reusable modules, enabling developers to encapsulate and share standardized infrastructure components. This encourages the DRY (D

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Basic OpenTofu Commands

Using OpenTofu is straightforward, with a set of core commands that follow a clear workflow for managing infrastructure. Whether you’re running OpenTofu directly or through a CI/CD pipeline like Harness IaCM, these commands form the backbone of your IaC operations:

opentofu init: The init command initializes your working directory. This sets up your configuration files and prepares your environment for running other OpenTofu commands.

opentofu plan: Before applying changes, plan generates a detailed execution plan, showing what changes will be made to your infrastructure. This step ensures that you review changes before implementing them.

opentofu apply: The apply command carries out the changes defined in your configuration. Once you’ve reviewed the plan, apply makes the modifications to your infrastructure, whether it’s creating resources, updating them, or deleting them.

opentofu destroy: The destroy command is used to clean up resources. When you no longer need infrastructure, destroy will tear it down, ensuring you avoid unnecessary costs or complexity.

opentofu validate: Before running a plan or apply, it’s good practice to use validate to check your configuration for syntax errors or inconsistencies. This helps catch issues early in the workflow.

opentofu state: The state command manages the state file, which tracks the current state of your infrastructure. You can use state to query, modify, or import resources into OpenTofu’s state file.

Here’s how these commands work in sequence:

1. Start by initializing your configuration with opentofu init.
2. Next, use opentofu plan to preview the infrastructure changes.
3. After reviewing the plan, apply the changes using opentofu apply.
4. Periodically, use opentofu state to manage or query the current state of your resources.

For those using Harness IaCM, OpenTofu commands like init, plan, and apply are automatically executed within your pipelines. Harness ensures these commands run with the correct context and credentials, streamlining your IaC processes.

Checkout how this commands can be executed in sequence with Harness IaCM.

FAQs

1. Is OpenTofu compatible with existing Terraform configurations?

   Yes, OpenTofu is designed to be compatible with existing Terraform configurations and state files.

2. Can I use Terraform providers with OpenTofu?

   Yes, OpenTofu can use existing Terraform providers.

3. How does OpenTofu handle state management?

   OpenTofu uses the same state management system as Terraform, including support for remote state storage.

4. Is OpenTofu suitable for enterprise use?

   Yes, OpenTofu is designed to be enterprise-ready, with features supporting large-scale infrastructure management.

5. How does the performance of OpenTofu compare to Terraform?

   As OpenTofu is a direct fork of Terraform, its performance is generally similar.

Conclusion

By leveraging Harness IaCM alongside OpenTofu, teams can move beyond manual IaC management to a fully automated, governed, and scalable solution. This combination provides the tools needed for consistent, secure, and efficient infrastructure provisioning, all while maintaining the open-source flexibility that OpenTofu offers.

For more information on getting started with OpenTofu in Harness, check out Harness IaCM or join our on-demand webinar to learn how GitOps and OpenTofu are shaping the future of IaC.

OpenTofu, combined with tools like Harness IaCM, is the future of Infrastructure as Code. Whether you’re building infrastructure at scale or just getting started with IaC, the flexibility and community-driven innovation offered by OpenTofu make it a must-have tool. Start exploring how OpenTofu and Harness IaCM can transform your infrastructure management today.