Ansible vs. Terraform

Ansible® and Hashicorp Terraform are 2 open source tools that embrace an Infrastructure as Code (IaC) approach to automating IT environments. Both tools are critical for managing infrastructure, but they serve different, specialized roles within the automation lifecycle. 

Terraform is a dedicated IaC tool designed to build, change, and manage infrastructure in a safe, repeatable way. Ansible is a multipurpose IT automation engine built to configure systems, deploy software, and orchestrate complex tasks across servers, network devices, security tools, and hybrid environments. The most effective modern automation strategies use Terraform and Ansible together to achieve comprehensive infrastructure lifecycle management.

Large organizations often transition from the core open source Ansible to Red Hat® Ansible Automation Platform to manage and scale their automation efforts. Ansible Automation Platform adds enterprise features, such as centralized governance, automation analytics, and official support. By understanding the role of Terraform for infrastructure provisioning and Ansible's configuration capabilities—plus Ansible Automation Platform for scaling automation—teams can develop an end-to-end automation strategy.

See how Red Hat and Terraform work together

Provisioning new IT environments used to be time consuming, expensive, and manual. As virtualization, containers, and cloud computing led to more—and more frequent—infrastructure changes, relying on manual processes became unsustainable.

That’s where IaC entered the picture. 

IaC is the process of managing and provisioning IT infrastructure through machine-readable code instead of manual configuration or hardware manipulation. 

Adopting IaC fundamentally shifts the relationship between developers and operations teams. Instead of clicking buttons in a cloud console or relying on ad hoc scripts, you create configuration files with complete infrastructure specifications. This helps you provision the same environment consistently every time, whether you’re deploying to development, staging, or production. By codifying and documenting your infrastructure in files you can edit, distribute, and place under version control, IaC helps eliminate errors, speed up deployments, and stop undocumented changes that lead to configuration drift.  

IaC is the foundation for modern DevOps and cloud strategy. Because this methodology defines infrastructure through code that’s automatically executed, you need specialized tools to translate those files into working infrastructure. Ansible, Red Hat Ansible Automation Platform, and Terraform help expedite and get more from IaC: Terraform specializes in creating the infrastructure, and Ansible specializes in configuring what runs inside it. 

Learn more about IaC

Despite specializing in different parts of the automation lifecycle, Terraform and Ansible have key similarities that define their success.

Agentless design

Ansible and Terraform both share a modern, simplified architecture that’s easier to run than older automation systems. Because they’re agentless, you don’t need to install special software or persistent agents on the servers or resources they manage, greatly simplifying setup. Terraform communicates primarily through cloud provider application programming interfaces (APIs), while Ansible executes tasks using standard protocols like SSH (Secure Shell) and APIs to communicate with managed nodes. 

Open source and community ecosystem

Both Ansible and Terraform are foundational open source projects with large, active user bases. This community ecosystem provides vast libraries of ready-to-use content. With thousands of providers, Terraform can interface with nearly every public cloud and platform. Likewise, Ansible offers modules and playbooks for almost any configuration task. This helps teams using either tool quickly find solutions and peer support.  

Complementary automation philosophy

Finally, both tools share the goal of automating infrastructure. While they specialize, they also have a functional overlap; for instance, Ansible can perform provisioning, and Terraform can execute basic configuration scripts. This means both work toward the same objective: turning manual, error-prone IT processes into repeatable, consistent code. Thanks to their common purpose, you can combine Ansible and Terraform to automate your entire workflow.

Automate application deployments, optimize infrastructure, and support continuous updates and troubleshooting with Ansible and Terraform. Video duration: 2:46.

Both tools are types of IaC, but they’re built differently to carry out their primary missions. Understanding these distinctions helps you choose the right tool for a task or decide how to integrate them. 

Declarative vs. procedural

The most foundational difference lies in how you tell each tool what to do:

• Terraform uses HashiCorp Configuration Language (HCL), a declarative configuration language. Declarative means you define the desired end state—what you want the infrastructure to look like. Terraform’s engine then automatically determines the steps necessary to reach that state, managing all dependencies for you.
• Ansible takes a mostly procedural (or imperative) approach to automation. It uses playbooks written in human-readable YAML. The procedural approach means you define the explicit step-by-step instructions—how to achieve the desired result. This task-based lets you precisely control and simplify troubleshooting because the execution order is clear. However, many underlying Ansible modules also act declaratively, making a change only if the target system isn’t already in the desired configuration state. 

Stateful vs. stateless

This difference impacts how each tool views and tracks the infrastructure over time:

• Terraform is stateful. It maintains a state file that acts as the single source of truth, tracking every infrastructure resource it provisions and its current configuration. The state file is essential because it lets Terraform manage the full lifecycle of a resource so it can reliably provision, scale, or retire resources when they’re no longer needed.
• Ansible is largely stateless. It doesn’t maintain a persistent state file tracking the entire infrastructure. Instead, it relies on idempotency—the guarantee that running the same task multiple times will yield the same result without making unnecessary changes. Ansible achieves its desired configuration by directly querying the target system before making a change.

Immutable vs. mutable

The tools are designed around different philosophies for handling infrastructure updates:

• Terraform prefers immutable—or unchangeable—infrastructure. If you need to make a substantial change or update, Terraform often favors tearing down the old resource and replacing it with a new, correctly configured resource. This strategy reduces the risk of complex configuration failures that can build up over time.
• Ansible is built for mutable infrastructure, meaning it excels at making in-place changes to existing, running systems. This is necessary for Day 1 and Day 2 tasks like applying security patches, running operating system updates, or adjusting firewall settings on a server that can’t be easily replaced.

Configuration drift

Configuration drift is when the infrastructure running in production deviates from what’s defined in the source code. Both tools address this, but differently:

• Terraform uses its persistent state file to actively detect drift. It can compare the currently running infrastructure against the state file and instantly flag any discrepancies.
• Ansible typically mitigates drift by running continuously and relying on idempotent tasks to always enforce the desired configuration. This prevents the system from drifting too far from the expected state.

The most valuable takeaway from comparing Terraform and Ansible is that it’s best to use them together instead of choosing just 1. Using the strengths of each tool helps organizations achieve complete, end-to-end automation—from the moment infrastructure is provisioned to the ongoing deployment and configuration of applications.

Lifecycle management

The most widely accepted practice is a straightforward, sequential handoff between the tools. Terraform handles the Day 0 provisioning, creating cloud infrastructure such as servers and networks. Once the infrastructure is successfully provisioned, Ansible takes over for Day 1 configuration, applying security policies, installing necessary software, and deploying the application code inside those new resources. Ansible also covers Day 2 operations like patching, updates, and configuration changes.

Orchestrating with Ansible

For complex workflows, Ansible Automation Platform can serve as the central orchestrator, wrapping Terraform execution within a broader automation process. Ansible Automation Platform can execute preprovisioning tasks and trigger a Terraform deployment to build the infrastructure. It can also execute postprovisioning tasks like application configuration while integrating with IT Service Management (ITSM) tools like ServiceNow for tracking purposes.

Terraform and Ansible Automation Platform integrations

Red Hat offers a certified collection of Terraform content for Ansible. It includes modules that help you manage and provision IaC using HashiCorp Terraform (HCP Terraform and Terraform Enterprise). The collection supports automation capabilities similar to other cloud-provisioning tool integrations for Ansible, such as AWS CloudFormation, Azure Resource Manager, and Helm.

Additionally, Hashicorp offers a Terraform provider for interacting with Ansible.  A Terraform provider is a plug-in that adds resources and data sources that Terraform can manage. Providers must be declared in the Terraform configuration so Terraform can install and use them. The Ansible provider for Terraform lets Terraform manage the Ansible inventory directly. Instead of requiring separate inventory plug-ins to manually gather information about newly provisioned infrastructure and pass it to Ansible, the provider automates the handover. Users can define the use of an Ansible inventory directly within their Terraform configuration, letting Ansible Playbooks run configuration tasks against the new hosts immediately upon creation.

Read more about the Terraform provider for Ansible

The open source tools—Terraform and Ansible—provide a foundation for IaC. But scaling and governing these integrated workflows across large organizations introduces significant security and consistency challenges. Red Hat Ansible Automation Platform reduces this complexity, transforming community automation into a strategic enterprise solution. It delivers the centralized control necessary to manage complex automation processes that span both Terraform provisioning and ongoing Ansible configuration.  

With open source at its core, Ansible Automation Platform is a trusted subscription product that offers full lifecycle support for organizations. It’s based on community Ansible, which benefits from the experience and intelligence of thousands of global contributors. Ansible Automation Platform helps organizations create, manage, and scale their automation workloads. It offers a flexible, stable, and security-focused foundation for deploying end-to-end automation—including for hybrid cloud, edge locations, networks, security, infrastructure, and many other use cases.

Learn more about Ansible Automation Platform