Lorenzo Sfienti

Importing Existing Infrastructure into Terraform


In the world of infrastructure provisioning and management, Terraform has emerged as a powerful tool that enables infrastructure-as-code practices. With its declarative language and wide range of supported providers, Terraform allows you to create, modify, and destroy infrastructure resources efficiently. However, what if you already have an existing infrastructure setup that you want to manage with Terraform? In this article, we will explore the process of importing existing infrastructure into Terraform and discuss the benefits, challenges, and best practices associated with it.

What is Terraform?

Terraform is an open-source infrastructure-as-code tool developed by HashiCorp. It allows you to define and manage your infrastructure resources in a declarative manner using a simple and concise language. Terraform supports various cloud providers, such as AWS, Azure, and Google Cloud, as well as on-premises infrastructure solutions. By using Terraform, you can provision, modify, and manage your infrastructure resources efficiently, ensuring consistency and reproducibility.

Benefits of Importing Existing Infrastructure

Importing existing infrastructure into Terraform offers several advantages. Firstly, it allows you to centralize the management of your infrastructure resources, regardless of their original provisioning method. By using a single tool like Terraform, you can apply consistent configurations and changes across your entire infrastructure, leading to improved maintainability and reduced human error. Additionally, importing existing infrastructure enables you to leverage Terraform’s state management capabilities, which provide a unified view of the infrastructure’s current state and facilitate change tracking.

Challenges of Importing Existing Infrastructure

While importing existing infrastructure into Terraform brings numerous benefits, it also presents certain challenges. One of the key challenges is mapping the existing infrastructure resources to their corresponding Terraform configurations. Since Terraform requires a declarative approach, you need to understand the current state of the infrastructure and express it in the Terraform language. This mapping process can be complex and time-consuming, especially for large and complex infrastructures. Furthermore, some resources may not have direct equivalents in Terraform, requiring you to find alternative solutions or workarounds.

Steps to Import Existing Infrastructure into Terraform

To import existing infrastructure into Terraform, you can follow these step-by-step guidelines:

Step 1: Understand the Existing Infrastructure

Before importing, gain a thorough understanding of the existing infrastructure and its components. Identify the resources you wish to manage with Terraform and their dependencies.

Step 2: Create Terraform Configurations

Create the necessary Terraform configurations to represent the desired state of the imported resources. Define the required providers, resources, and variables based on the infrastructure’s characteristics.

Step 3: Import Resources

Use the terraform import command to import each resource into Terraform. Provide the appropriate resource identifier, which varies depending on the infrastructure provider and resource type.

Step 4: Verify and Update Configurations

After importing, verify that the resources are accurately represented in the Terraform state. Make any necessary adjustments to the configurations to align them with the desired state.

Step 5: Apply Changes

Apply changes using the terraform apply command to ensure that Terraform manages the imported resources going forward. This step establishes the connection between Terraform and the infrastructure.

Example: Importing an Existing AWS Infrastructure

Let’s consider an example of importing an existing AWS infrastructure into Terraform. Assume you have an AWS VPC, EC2 instances, and security groups already provisioned manually. To import these resources, you would follow the steps outlined above, providing the appropriate identifiers for each resource.

Best Practices for Importing Infrastructure

To ensure a smooth and successful import of existing infrastructure into Terraform, consider the following best practices:

  • Start with a small, well-defined subset of resources before tackling the entire infrastructure.
  • Document the mapping between existing resources and Terraform configurations for future reference.
  • Leverage Terraform modules to encapsulate common patterns and promote reusability.
  • Utilize version control to track changes in your Terraform configurations.
  • Test changes in a staging environment before applying them to production.


Importing existing infrastructure into Terraform can be a challenging yet rewarding endeavor. By consolidating your infrastructure management under Terraform’s umbrella, you can achieve improved consistency, reproducibility, and scalability. While the process requires careful planning and mapping, the benefits of centralizing infrastructure management outweigh the initial effort. Embrace the power of infrastructure-as-code and take advantage of Terraform’s capabilities to streamline your operations.