Ansible vs Terraform: Comparing Infrastructure Automation Tools

Ansible vs Terraform are the two most popular tools in the DevOps space, serving distinct roles according to statista. Ansible is a configuration management and IT automation tool that simplifies repetitive tasks and uses human-readable YAML syntax which makes it a good choice for beginners as well as advanced users.

Terraform excels in the infrastructure provisioning space. It helps organizations provision and orchestrate tasks declaratively in a multi-cloud environment. Many organizations add both of them to their DevOps toolchain to enjoy a comprehensive and efficient IT automation workflow.  This blog deep dives into the Ansible vs Terraform debate to help you understand the difference between Ansible and Terraform.

Table of contents

• An Overview of Infrastructure as Code
• Difference Between Ansible vs Terraform
• Ansible vs Terraform: What is Ansible?
• Advantages and Disadvantages of Ansible
• Ansible Use Cases
• Terraform vs Ansible: What is Terraform?
• Advantages and Disadvantages of Terraform
• Disadvantages of Terraform
• Similarities Between Terraform vs Ansible
• Difference Between Ansible vs Terraform
• How to Use Terraform and Ansible Together?
• Conclusion
• FAQs

An Overview of Infrastructure as Code

The advent of Infrastructure as Code (IaC) has revolutionized the infrastructure management space. IaC enables organizations to provision and manage the IT infrastructure using code. 

IT resources are provisioned programmatically using declarative or imperative scripts and thereby offer IT automation, version control and collaboration while eliminating manual errors. It enhances scalability and accelerates deployment cycles. This shift rightly aligns with modern software principles and enables organizations to evolve towards more agile, efficient and automated IT operations. It also brings Terraform vs Ansible into the picture.

Difference Between Ansible and Terraform

Both Ansible and Terraform contribute to a broader goal of automating and managing IT infrastructure. While there are some overlaps in their capabilities, Ansible and Terraform don’t directly compete with each other but are often used together in complementary roles. 

When it comes to Ansible vs Terraform, Ansible is a configuration management tool, while Terraform is an infrastructure provisioning tool. Together, they address different aspects of the DevOps lifecycle. This collaboration enables organizations to benefit from the strengths of each tool and adopt a holistic approach to IT automation. Understanding the difference between Ansible and Terraform enables organizations to fully leverage their capabilities.

Ansible vs Terraform: What is Ansible?

Before delving into the Terraform vs Ansible debate, it is important to understand how each tool works. Ansible is a popular open-source IT automation and configuration management tool that enables users (like developers, system administrators and architects) to streamline and simplify IT operations. Be it software installation, application deployment, or configuration management, users can automate system administration tasks across a large number of devices using Ansible. 

Ansible is written in Python. It uses human-readable language that makes it easy to use and without a big learning curve. With minimal moving parts, Ansible brings security and reliability onto the plate. It is easy to use as there is no custom security infrastructure or agent system.

Ansible was written by Michael DeHaan in 2012 using Python, PowerShell and Shell. DeHaan started AnsibleWorks Inc. in 2013, later renamed Ansible Inc and later acquired by Red Hat in 2015. Red Hat offers Ansible as a part of Fedora’s distribution of Linux.

Ansible Key Features

Here are some key features and concepts of Ansible:

• Agentless: One of the key features of Ansible is its agentless architecture. With Ansible, you don’t need to install agents or any other software on the target machines. Ansible connects to target machines and controls them using SSH (Secure Shell) or other remote protocols, making it less intrusive and easier to manage.
• Playbooks: Ansible uses Playbooks to define and automate the infrastructure. A Playbook is a configuration file that contains a description of a series of tasks along with their dependencies. Playbooks are written in YAML format.
• Ad-hoc Commands: In addition to Playbooks, you can use Ad-hoc commands to perform quick tasks such as making a one-time change, checking the system status etc.
• Roles: Ansible allows you to organize and reuse the content of Playbooks using Roles. By organizing a set of variables, files or tasks, you can easily manage and share automation code.
• Modules: Ansible uses Modules to interact with systems and perform tasks such as file manipulation, package management, and service management. Ansible offers a large array of built-in modules and allows you to create custom modules, too.
• Idempotent: Ansible allows you to run a Playbook multiple times without causing unwanted changes to the system when it is in the desired state.
• Inventory: The list of target systems that Ansible manages is called inventory. Inventories can be defined in a simple text file. You can also use scripts or plugins to generate dynamic inventories.

Read the blog on the best practices of Ansible

Advantages and Disadvantages of Ansible

Advantages

• With agentless architecture, you don’t need to install and manage agents on every target system.
• Ansible Playbooks are written using YAML format, which is human-readable and easy to understand.
• Ansible modules don’t make any unnecessary changes when the system is in desired state, making it more predictable and reliable for task automation.
• Is highly extensible, with a broad range of built-in modules and plugins and the option for custom modules.
• Ansible inventory system allows you to group systems based on specific criteria, simplifying organization management.
• Ansible supports parallel execution of tasks, making configuration and deployment faster and more effective in large environments.
• The ‘Roles’ feature allows you to break complex automation scenarios into smaller and more manageable components. You can organize Playbooks using Roles.
• Ansible supports all major cloud platforms such as AWS, Google Cloud and Microsoft Azure. You can manage on-premise and cloud environments consistently.
• Ansible uses declarative language that simplifies the creation of automation scripts and enhances readability as well.

Ansible Use Cases

Ansible Use Cases
	Use Case	Example
Configuration Management	Enforce and maintain consistent configurations across server and network devices.	You can define and apply configuration settings for web servers, databases, or network devices to ensure uniformity and compliance across the organization.
Application Deployment	Automate the deployment of applications and services.	Deploy and update applications, middleware, and services across multiple servers or environments with a single playbook.
Infrastructure Provisioning	Automate the creation and provisioning of infrastructure resources.	Dynamically create and configure virtual machines, cloud instances, or containers based on defined specifications.
Continuous Integration and Continuous Deployment (CI/CD)	Automate build, test, and deployment processes in a CI/CD pipeline.	Integrate Ansible into CI/CD workflows to automate testing, building, and deploying applications.
Security Compliance and Patch Management	Enforce security policies and apply system patches.	Ensure that systems adhere to security standards by automatically applying security patches, configuring firewalls, and performing compliance checks.
Orchestration of Complex Workflows	Coordinate and orchestrate complex tasks involving multiple servers and services.	Automate end-to-end deployment processes, including provisioning infrastructure, configuring servers, and deploying applications.
Inventory Management	Manage and organize an inventory of infrastructure assets.	Dynamically generate and update an inventory file based on changes in the infrastructure, making it easier to manage and group hosts.
Disaster Recovery	Automate disaster recovery processes.	Create playbooks that define recovery procedures, such as restoring backups, configuring failover systems, and ensuring data integrity.
Logging and Monitoring Configuration	Automate the configuration of logging and monitoring tools.	Define and apply configurations for tools like ELK (Elasticsearch, Logstash, Kibana) or Prometheus to centralize logs and monitor system health.
User and Access Management	Automate user provisioning and access management.	Create playbooks to add or remove users, manage permissions, and ensure consistent access control across servers.
Database Operations	Automate database provisioning, configuration, and maintenance.	Create playbooks to add or remove users, manage permissions, and ensure consistent server access control.
Networking Tasks	Automate network-related tasks on routers, switches, and firewalls.	Create and manage databases and database users, and perform routine maintenance tasks on database servers.

Terraform vs Ansible: What is Terraform?

Terraform is a popular Infrastructure as Code (IaC) from HashiCorp that enables users to define and provision IT infrastructure resources using a declarative configuration language. The tool was created by Mitchell Hashimoto in the Go language in 2014. 

The tool allows you to define your infrastructure resources such as servers, network and storage in a configuration file. Terraform interprets this file and automates the process of creating, managing and updating the corresponding infrastructure in a variety of environments. 

Terraform Key Features:

Here are some key concepts of Terraform:

• Declarative Language: Terraform uses a high-level declarative configuration language called the HashiCorp Configuration Language (HCL) to define the desired state of a system. You just need to describe what the infrastructure looks like and the tool will figure out the required steps.
• Infrastructure as Code: Terraform enables you to treat the infrastructure as code. It means you can version control the infrastructure configurations, collaborate easily, reuse code and efficiently track changes to infrastructure over time.
• Resources: In Terraform, a resource represents an infrastructure component such as a virtual machine, storage or network defined in a configuration file.
• Modules: A module is a self-contained unit of Terraform configuration for parameterizing infrastructure components. This allows you to organize and reuse configurations.
• Plan and Apply Workflow: Terraform uses a `Plan and Apply Workflow’, a 2-step process to perform infrastructural changes. While the `Terraform Plan’ examines the configuration and provides the changes being made, the `Terraform Apply’ feature will execute those changes. So, you can preview changes before applying them to the infrastructure.
• State Management: Terraform uses a state file to keep track of the state of the infrastructure so that you can plan and apply changes only to the resources that require updating.
• Graph Dependency Resolution: Terraform creates a dependency graph based on the configuration to determine the right order in which it should create or modify resources. This will eliminate resource dependency issues.

Read our blog Terraform vs CloudFormation, to learn more about this debate

Advantages and Disadvantages of Terraform

Advantages

• Terraform supports Parallel execution so you can run tasks on multiple resources concurrently. This is beneficial for large-scale deployments.
• Terraform’s Plan and Apply Workflow allows you to see modifications before applying them and thereby eliminate unintended consequences.
• As Terraform configurations are version-controlled, you have a historical record of all changes to the infrastructure. This helps in auditing and rollbacks.
• Terraform can be incrementally adopted to manage existing infrastructure without taking the risk of a complete overhaul.
• Terraform enjoys a large and active community. You can get many pre-built modules, plugins and shared configurations.
• Terraform supports multi-cloud and multi-provider environments, offering the flexibility to manage infrastructure across a variety of platforms.
• With reusable components called Modules, Terraform supports modularization for code organization and reusability.
• Terraform automatically manages dependencies between resources.

Read our blog on the 24 Terraform best practices

Disadvantages

• There is a learning curve, especially for users new to declarative languages and IaC concepts.
• With Unix/Linux-focused design, Terraform offers limited support to Windows environments.
• In dynamic environments, managing and securing Terraform state files can be challenging.
• Terraform lacks built-in support for managing sensitive information such as API keys or passwords. You have to integrate 3rd party tools for this purpose.
• The built-in error handling feature offers basic functionality and can be improved.

Terraform Use Cases

Terraform Use Cases
	Use Case	Example
Multi-Cloud Deployment	Deploy and manage infrastructure across multiple cloud providers.	Provision resources on AWS, Azure, and Google Cloud using a single set of Terraform configurations, ensuring consistent deployments.
Infrastructure Provisioning	Automate the creation and provisioning of infrastructure components.	Dynamically create and configure virtual machines, storage, and networking resources in response to changing requirements.
Environment Standardization	Ensure consistent configurations and standards across development, testing, and production environments.	Use Terraform to define and deploy infrastructure configurations, ensuring each environment matches the desired specifications.
Container Orchestration	Automate the deployment and scaling of containerized applications.	Use Terraform to provision and manage resources in Kubernetes clusters or other container orchestration platforms.
Network Infrastructure Configuration	Automate the configuration of network components such as virtual networks, subnets, and firewalls.	Define and deploy networking configurations to ensure secure and isolated environments.
Application Stacks Deployment	Deploy and manage complex application stacks consisting of multiple interconnected components.	Define and provision resources for a web application, including web servers, databases, and load balancers.
Serverless Architecture	Automate the deployment of serverless functions and services.	Use Terraform to provision AWS Lambda functions, Azure Functions, Google Cloud Functions, and associated resources.
Immutable Infrastructure	Adopt immutable infrastructure practices by rebuilding and redeploying infrastructure components instead of modifying existing instances.	Update an entire environment by creating new instances with the desired changes and destroying the old ones.
Hybrid Cloud Deployments	Manage infrastructure across both on-premises data centers and public cloud environments.	Extend existing on-premises infrastructure to the cloud or create hybrid configurations using Terraform.
Collaborative Development Environments	Facilitate collaboration by providing developers with a standardized and automated way to create development environments.	Developers can use Terraform to spin up identical development environments quickly for consistency across the team.
Logging and Monitoring Infrastructure	Automate the deployment and configuration of logging and monitoring tools.	Use Terraform to provision resources for ELK stack (Elasticsearch, Logstash, Kibana) or other monitoring solutions.
Disaster Recovery Planning	Define and automate the creation of infrastructure components necessary for disaster recovery.	Quickly provision backup environments in a secondary region in case of primary data center failures.

Similarities Between Terraform vs Ansible

It is not always about Ansible vs Terraform or Terraform vs Ansible. They perform similar tasks as well. Here are some of the similarities between Terraform and Ansible.

Ansible vs Terraform: Setting up the new cloud infrastructure

When it comes to setting up the new cloud infrastructure, Terraform is specially designed for this purpose as an Infrastructure as Code (IaC) tool. While Ansible is designed with configuration management in mind, it effectively enables users to set up the new cloud infrastructure easily. 

Ansible vs Terraform: Remote Commands on the Virtual Machines

Ansible and Terraform support the execution of remote commands on virtual machines. Ansible is well-known for its remote execution capabilities. Though Terraform focuses on infrastructure provisioning, it has the capabilities to run remote provisioners.

Ansible vs Terraform: Declarative Approach

In a declarative approach, users define the state of the system and the tool determines how to achieve that state. When it comes to Ansible vs Terraform, both tools take a declarative approach to infrastructure as code. While Ansible uses Playbooks to define the state of a system written in YAML format, Terraform uses Hashicorp Configuration Language (HCL) for this purpose. Ansible also takes a hybrid approach (procedural and declarative configurations) wherein it executes ad-hoc commands for procedural configurations.

Ansible vs Terraform: Use of SSH

Both tools connect to and manage remote machines utilizing SSH. Ansible primarily uses SSH to manage remote machines. While Terraform is an IaC tool, it works in conjunction with Ansible for configuring provisioned infrastructure, which involves SSH.

Ansible vs Terraform: Integration with Other Tools

Both tools have the capabilities to integrate with other tools and be a part of a larger toolchain in a DevOps environment. You can integrate these tools with CI/CD pipelines, version control systems or monitoring and logging tools to automate and manage solutions.

Summary Table Terraform vs Ansible

	Ansible	Terraform
Setting up the new cloud infrastructure	Ansible can also handle configuration management tasks involved in setting up and configuring infrastructure.	Terraform is specifically designed for infrastructure provisioning.
Remote commands on the virtual machine	Ansible is highly popular for its remote execution capabilities	While Terraform focuses more on infrastructure provisioning, it has provisions for running remote provisioners.
Declarative Approach	Ansible playbooks are written in a declarative manner. It also executes ad-hoc commands to implement procedural configurations.	Terraform uses declarative language for infrastructure as code.
Use of SSH	Ansible uses SSH to connect to and manage remote machines	Terraform works in conjunction with tools like Ansible to provision remote infrastructure, involving SSH.
Integration with Other Tools	Ansible supports 3rd party integrations	Terraform allows 3rd party integrations.

Difference Between Ansible vs Terraform

Here are some of the key differences concerning Ansible vs Terraform based on the following criteria:

Ansible vs Terraform: Purpose

While both tools perform configuration management and infrastructure provision automation, they are created with different purposes. Ansible is primarily designed for configuration management of the infrastructure. However, it is also used for infrastructure provisioning, application deployment automation, and task orchestration. On the other hand, Terraform is basically an IaC and orchestration tool that can also perform configuration management.

Ansible vs Terraform: Type of Tool

Ansible falls into the category of configuration management software, while Terraform belongs to the Infrastructure as Code (IaC) category. This is a key differentiator in the Ansible vs Terraform discussion.

Ansible vs Terraform: Syntax and Language

Ansible is written in Python. As most Linux distributions contain Python libraries, it becomes easy to install and set up the tool. It uses Playbooks to deploy and manage nodes. A playbook is a configuration file that is written in YAML format which is easy for humans to read and write, compared to JSON or XML. You can orchestrate steps in a specific order or launch tasks asynchronously/synchronously using Playbooks. The syntax is minimal in YAML format. 

When it comes to execution, Ansible runs Playbooks from top to bottom. The same is the case with tasks within each play. You can create modules in any language provided that it returns data in JSON format.

Terraform uses a high-level configuration language Hashicorp Configuration Language (HCL). HCL is easy to read and understand. The syntax contains fewer elements and is easy to follow. Terraform also supports JSON format. 

Ansible vs Terraform: Execution Model

Ansible follows a Push-based approach wherein the control machine pushes the configurations to the target machines. Ansible is executed from the control node when a user runs an Ansible-playbook command. The control node pushes Ansible-Modules to the managed machines and executes them over SSH. Once the task is done, Ansible removes them. These modules are idempotent which means they don’t make a change when the target system is already in the desired state. Ansible operates without a separate state file

The main difference between Terraform and Ansible is that Terraform uses a Pull-based model wherein the clients pull the configuration and execute the plan to provision the infrastructure. Users can run the ‘terraform state pull’ command to manually download the state from the current location and update the local copy. The system is then updated to the desired state. Terraform maintains a state file that keeps track of the current state of the infrastructure.

Ansible vs Terraform: Lifecycle Management

Ansible supports configuration management but is not designed for full infrastructure lifecycle management. By default, Ansible assumes immutable infrastructure and automatically applies configurational changes to the target machines. Terraform supports lifecycle management, including infrastructure provisioning, updating, and destruction. By supporting lifecycle arguments, Terraform allows users to define custom rules for creating or destroying a resource. This will help you to eliminate the risk of specific resources changing the infrastructure and also minimize downtime based on the needs of a resource. 

Ansible vs Terraform: Capabilities

Ansible is popular for configuration management tasks. It also performs application deployment, task automation and some orchestration capabilities. 

Terraform stands tall in the infrastructure provisioning space with capabilities including orchestration and management of cloud resources and support for multi-cloud environments. 

Ansible vs Terraform: Packaging and Templating

Ansible uses Playbooks and roles to organize and package configurations. It supports Jinja2 templating for dynamic content.

Terraform uses modules to organize and package infrastructure code. HCL allows you to define reusable and modular components. 

Summary Table Terraform vs Ansible

	Ansible	Terraform
Purpose	Primarily used for configuration management	Primarily an infrastructure provisioning and orchestration tool
Type of Tool	Configuration Management and Automation tool	Infrastructure as Code (IaC) tool
Syntax and Language	Uses YAML for Playbooks	Uses HCL for defining infrastructure as code
Execution Model	Push-based model	Pull-based model
Lifecycle Management	Not designed for full infrastructure lifecycle management	Supports full lifecycle management
Capabilities	Configuration management, application deployment, task automation, and some orchestration capabilities.	Infrastructure provisioning, orchestration, and management of cloud resources, including support for multi-cloud environments.
Packaging and Templating	Uses playbooks and roles for organizing and packaging configurations. Supports Jinja2 templating for dynamic content.	Uses modules for organizing and packaging infrastructure code. HCL allows for the definition of reusable and modular components.

How to Use Terraform and Ansible Together?

It’s not just Ansible vs Terraform. Using Terraform and Ansible is a common practice in a DevOps workflow. Considering the fact that one tool excels in infrastructure provisioning and the other in configuration management, you get the best of both worlds. 

a) Using the Ansible Provider in Terraform

1. Define infrastructure with Terraform: Define the infrastructure components you want to provision using Terraform. Write Terraform configuration files to describe the state of your infrastructure.
2. Provision Infrastructure: Run Terraform commands to initialize, plan, and apply the changes to your infrastructure.
   1. terraform init
   2. terraform plan
   3. terraform apply
3. Use Terraform Output: Output relevant information from the Terraform state such as IP Addresses, instance IDs or other resource attributes that Ansible will use during the configuration.
4. Configure with Ansible: Write Ansible Playbooks (in YAML) to configure the provisioned infrastructure and define tasks to be executed on hosts.
5. Run Ansible Playbook: Run Ansible Playbooks against the provisioned configuration by providing required connection parameters such as SSH or remote user.
6. Integrate Ansible with Terraform: To streamline this process, integrate Ansible with Terraform using the `local-exec’ provisioner in Terraform so that Ansible playbooks can be triggered when Terraform applies changes to the infrastructure.
7. Destroy Infrastructure: When you no longer need the infrastructure, destroy it using Terraform.

• terraform destroy

This command terminates all resources managed by the current Terraform project. Terraform will provide the details of the resources that will be terminated. Make sure to carefully checkout the displayed resources and then confirm the termination, as this action cannot be undone later.

8. Cleanup: As a best practice, clean up any remaining state files or resources.

b) Deployment of stacks in new infrastructures created by Terraform

When you integrate Terraform with Ansible, you can automate the deployment of stacks in new infrastructures created by Terraform. Here are the steps to do so:

1. Write Terraform Configuration: Use Terraform to create infrastructure components you want to provision while including the necessary outputs Ansible will be using.

2. Provision infrastructure with Terraform: Run Terraform commands to initialize, plan, and apply the changes to your infrastructure.
   1. terraform init
   2. terraform plan
   3. terraform apply

3. Capture Terraform Output: Capture Terraform output that can be used by Ansible.

4. Write Ansible Playbook: Create an Ansible playbook to configure and deploy your application stack while referencing the output values obtained from Terraform in the playbook.

5. Run Ansible Playbook: Run the Ansible playbook to execute tasks against the provisioned infrastructure, passing the required parameters.

6. Integrate Ansible with Terraform: To streamline this process, integrate Ansible with Terraform using the `local-exec’ provisioner in Terraform so that Ansible playbooks can be triggered when Terraform applies changes to the infrastructure.

7. Verify and Monitor: Verify that the stack is deployed successfully and monitor the application and the infrastructure for any issues.

8. Destroy Infrastructure:  When you no longer need the infrastructure, destroy it using Terraform.

Conclusion of Terraform vs Ansible

While both Ansible and Terraform have the capabilities to perform similar tasks, they are designed with different purposes in mind. Ansible excels in configuration and automation tasks and is popular for its simplicity and versatility. The push-based model and YAML syntax make it user-friendly. 

On the other hand, Terraform focuses on infrastructure provisioning. With its declarative language, state management and multi-cloud provisioning, Terraform is popular among organizations that emphasize infrastructure orchestration. While they address different aspects, you can combine them to bring the best of both worlds.

While Terraform handles infrastructure provisioning, Ansible takes care of configuration management for efficient and comprehensive IT automation. It’s not about Ansible vs Terraform or Terraform vs Ansible but Terraform and Ansible.

Terraform vs Ansible FAQs