OpenTofu vs Terraform

If you’re a DevOps or Infrastructure engineer, chances are you’ve used Terraform to manage cloud infrastructure. Terraform has been one of the most widely used IaC tools out there for the last decade and has a customer base of over 25,000 customers and a market share of 32.93%. Why do engineering teams love Terraform? Because it simplifies infrastructure provisioning without the need to rely on cloud consoles or shell scripts. With Terraform, teams simply define their infrastructure as code, allowing them to build and manage their cloud environment to match their exact specifications, while maintaining state. It integrates seamlessly with all major cloud providers—AWS, Azure, and GCP—and even supports on-premises environments. No matter the size or complexity of your setup, Terraform ensures consistency, reliability, and scalability across your infrastructure.

In 2023, HashiCorp switched Terraform’s licensing from open-source to a business source license. This shift added limitations on the usage of terraform. That’s when the OpenTofu community created OpenTofu as an open-source fork of Terraform. In this blog, we’ll look at the similarities and differences between Terraform and OpenTofu and why most organizations are moving towards OpenTofu. Additionally, we’ll walk you through the migration steps and recommend some tips for effective infrastructure management when used with either of these tools. The tl;dr? They're very similar! OpenTofu is a fork of Terraform version 1.5.6. Both tools allow you to define infrastructure as code, manage resources using providers, and track infrastructure states with a state file.

OpenTofu vs. Terraform: Key Differences
While both tools share the same foundation, there are a few important distinctions between them. The main differences are due to licensing, encryption support, and ongoing maintenance. Here’s a closer look:

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These differences are why some teams are switching to OpenTofu from Terraform. Its open-source nature ensures freedom from licensing restrictions and commercial use while still maintaining compatibility with all Terraform’s features. On the other hand, Terraform offers official support and a well-defined update cycle managed by HashiCorp.

Why Are Organizations Migrating to OpenTofu?

• Open-Source and Free: OpenTofu is a fully open-source project, Apache 2.0 licensed, so it's free and unrestricted for anyone to use. 
• No Vendor Lock-In: OpenTofu is owned by no single entity, so it will stay free of corporate control and simple to license. The independence of this long-term choice ensures that OpenTofu is a reliable and safe choice for users.
• Compatible with Terraform: The goal of OpenTofu is for it to be compatible with Terraform. It supports the same configurations, providers, and workflows that Terraform users are used to. This effectively means that teams don’t have to rewrite your existing infrastructure code or how you manage resources to use OpenTofu.
• Community-Driven: The Linux Foundation and a global community of contributors back the OpenTofu team, making sure the tool remains transparent and evolves to meet user needs. They also include companies like Spacelift and env0 that help contribute to the ecosystem.

Migrating from Terraform to OpenTofuMigrating to OpenTofu doesn’t require major changes and can be done with a few simple steps. Let’s walk through the process:

Step 1: Back Up Your State File and Code

Before starting, create a backup of your Terraform state file (terraform.tfstate) and your configuration files to make sure that you can recover if anything goes wrong within the migration process. You can do this by copying the state file to a different location:

cp terraform.tfstate /kapstan/instances/prod/backup/

Also, back up your Terraform configuration files (*.tf and related files) by archiving them:

tar -czvf terraform-config-backup.tar.gz *.tf

These steps make sure that you have a recovery point in case of any issues during the migration. 

Step 2: Install OpenTofu

To install OpenTofu, visit the OpenTofu website, download the binary for your operating system, and move it to a directory in your system’s PATH. Once installed, verify it by running:

tofu version

Step 3: Update Your Configuration Files and Workflows

OpenTofu uses the same syntax as Terraform, so you don’t need to rewrite your .tf files. Instead, replace any Terraform commands in your scripts and CI/CD pipelines with OpenTofu commands. For example:

• Replace terraform init with tofu init.
• Replace terraform apply with tofu apply.

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Step 4: Reinitialize Your Project

Reinitialize your project directory with the following command:

tofu init

During this step:

• Updates may be made to the .terraform.lock.hcl file.
• Provider references like registry.terraform.io/hashicorp/azurerm will be updated to align with OpenTofu’s provider conventions.

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OpenTofu supports all Terraform providers, but if you encounter any mismatches or issues, check the OpenTofu provider documentation.

Step 5: Verify the State File

After initialization, OpenTofu will detect and use your existing terraform.tfstate file to track the current state of your infrastructure. You can confirm this by running tofu show, which displays the imported state.

Step 6: Run a Dry Plan

Before making any changes, it’s a good idea to run a dry plan using tofu plan. This command previews the changes OpenTofu will make to your infrastructure based on your configurations. Carefully review the output to make sure that everything is as expected.

Step 7: Apply Changes

When you’re ready, use tofu apply to implement the changes. During this step:

• OpenTofu will update the state file to reflect the new changes.
• You might see updates in the provider references, such as “provider_name”: “registry.terraform.io/hashicorp/azurerm”, making sure that the state file remains consistent with the applied infrastructure.

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If you’re using Terraform-specific functions like encode_tfvars, decode_tfvars, or encode_expr, note that these are not supported in OpenTofu 1.8. Instead, use native HCL functions like jsonencode and jsondecode, or external tools like jq for complex tasks.

Step 8: Update Documentation

We get it - this part sucks. Nobody wants to do this. Why are we wasting space to talk about updating documentation?

At Kapstan, we're firm believers that DevOps isn't just about implementing tools or technologies; it's a set of practices that fundamentally reshape how teams collaborate, build, and deliver software. The DevOps practice focuses on breaking down silos between development and operations, fostering a culture of shared responsibility, continuous improvement, and faster, more reliable delivery.

So don't skip this step! Update your team and project documentation to reflect the use of OpenTofu ensures that everyone within your team is familiar with the new commands and workflows, ensuring a smooth transition. making the transition smooth. Version CompatibilityOpenTofu is based on Terraform version 1.5.6. Configurations from this version or earlier can be migrated easily. If you’re using Terraform 1.6 or newer, refer to the OpenTofu migration guide for specific differences. By following these steps, you can easily migrate from Terraform to OpenTofu with minimal effort while keeping your existing workflows untouched.

What are the Best Practices when using IaC?

Whether you are using Terraform or OpenTofu, a few simple practices can make a big difference in keeping your infrastructure more reliable and efficient.

• Validate configs early: Run terraform validate or tofu validate before applying changes to catch errors and avoid deployment issues.
• ‍Use remote state backends: Store your state file in a remote backend like S3, Azure Storage, or GCS to enable locking, versioning, and team collaboration.
• ‍Set up CI/CD: Automate validation, planning, and apply steps with a CI/CD pipeline to ensure consistent, tested deployments.
• ‍Clean up unused resources: Regularly audit and remove unused infrastructure to reduce costs and maintain a tidy environment.

Following these practices will help you maintain a clean, secure, and well-functioning infrastructure, regardless of the tool you choose. Managing Infrastructure as Code is a must for ensuring consistency across environments, version control, auditability, and disaster recovery in software development today. However, this comes with an additional cost and hassle of learning and maintaining terraform. That’s where Kapstan comes in.

Introduction to Kapstan

‍Kapstan simplifies infrastructure management by using OpenTofu under the hood for provisioning and managing customer infrastructure. It takes care of the complexities, so you don’t have to write or run scripts yourself. Kapstan lets you deploy a new kubernetes cluster, databases, caches, queues, or any other modern infrastructure in a few simple clicks. Think of Kapstan as a way to abstract terraform from your developers, while still having all the power and flexibility IaC offers. Take a look at 2 examples below.

1. Launching a well architected, and compliant EKS cluster takes 30 seconds of effort. We ensure the cluster is set up properly, with pre configured add ons, such as Karpetner and Istio. All Kapstan requires is your cluster name, your cloud, and whether you want a staging vs production cluster (effectively, this is a cost vs reliability exercise).

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2. Launching a NATS queue takes 10 seconds. Just give Kapstan the name, and let us know if you'd prefer Cluster Mode or JetStream mode.

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If you prefer not to use Kapstan’s opinionated templates for launching resources, Kapstan also supports bringing your own Terraform.

DevOps teams can define custom templates for their infrastructure, expose only the parameters they want developers to configure, and make these templates available directly on Kapstan. This approach streamlines collaboration by reducing back-and-forth requests between DevOps and development teams, offering flexibility while minimizing dependency. "Bring Your Own Terraform" enables DevOps teams to maintain consistent infrastructure across various teams and environments without micromanaging every infrastructure deployment. Kapstan doesn’t stop at just provisioning resources. It solves some common challenges faced by most DevOps engineers by adding features that make managing your infrastructure much smoother. Here’s how Kapstan stands out:

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Conclusion

We hope this guide has been helpful in giving you some more context about Terraform and OpenTofu, the reasons many teams have opted to choose OpenTofu, and how easily your team can make this migration. And if you'd like some additional help in making this migration, while also bringing in some DevOps self service capabilities for your developers, we'd be happy to chat.

FAQs

Q. Is OpenTofu ready for production?

A. Yes, OpenTofu is production-ready and works just like Terraform. It’s designed for stability and reliability in real-world environments.

Q. Why are people moving away from Terraform?

A. The licensing change in 2023 made many users uncomfortable with restrictions. OpenTofu gives them the same functionality without the lock-in.

Q. Can I use Terraform providers with OpenTofu?

A. Absolutely. OpenTofu supports the same providers, so you don’t need to change anything in your existing setup.

Q. When should I not use Terraform?If you value full control and open licensing,
AOpenTofu might be a better fit. Otherwise, Terraform works well for most cases.

Q. What Terraform versions can I migrate to OpenTofu
A.?OpenTofu is based on Terraform version 1.5.6. If your configurations use this version or an earlier one, you can migrate them easily.