Terraform Versus Pulumi: Choosing Your IaC Tool

A robust organizational infrastructure provides a sure foundation to enhance an organization’s performance. Yet, provisioning this infrastructure traditionally meant employing a team of storage administrators, field engineers, backup admins, and system admins to maintain your on-premise data center.

Although this traditional approach can accomplish your objectives, it struggles with slow development, high maintenance and setup costs, minimal automation, and human errors. That said, cloud-based infrastructure can be the ideal solution for your organization. Subsequently, infrastructure as code (IaC) can play a vital role in further improving cloud infrastructure speed and accuracy.

We wrote previously about where to begin with infrastructure automation and IaC. Two of the popular IaC solutions mentioned are Terraform and Pulumi. While either solution can be greatly beneficial and can solve the same issue, they use significantly different approaches. So, it can be challenging to choose the ideal option for your needs.

Let’s compare Terraform to Pulumi and empower you to select the best IaC solution for your specific requirements and development background.

What is Terraform?#

Terraform entered the market in 2014. It is an open-source laC solution that helps you maintain and provision cloud infrastructures.

You use a custom declarative language to describe Terraform’s required components. Then, Terraform generates a plan to achieve your desired outcome.

Terraform’s plan command evaluates the Terraform configuration to determine the desired states of the declared resources. Then, it compares the desired state to that of the actual infrastructure objects managed in the current workspace and directory.

Once the comparison is complete, Terraform describes the changes required to accomplish the desired state. Then, when you agree with the plan, Terraform executes the entire backend process to establish the desired infrastructure state.

You can also use the Terraform apply command to change individual resources using the infrastructure provider's API. Before applying these changes, the command creates a new plan and asks you to confirm. It can also accept the plan file produced by Terraform plan instead of running a new plan.

Terraform offers the freedom to manage multiple offerings and multi-cloud environments more efficiently, with a user-friendly experience. It helps escape the complications of control flow, code blocks, and classes because its workflow relies on plan, apply, and destroy commands. You can easily create your first cloud infrastructure by initiating these commands to achieve the desired state described in a Terraform configuration. Its engine handles all its state management, unlike Pulumi, which leverages the Pulumi service and general-purpose language.

Terraform is compatible with macOS, Linux, and Windows, and supports detailed documentation of all the leading cloud infrastructure providers.

Terraform can also provide low-level components, like networking and storage, and high-level components, such as DNS entries.

Terraform’s HashiCorp Configuration Language#

Terraform users provide and define data center infrastructure using a domain-specific language (DSL) called HashiCorp Configuration Language (HCL). Users employ HCL to specify the resources and service providers within the network. HCL provides arguments, expressions, and blocks to simplify the Terraform configuration.

Block groups items or tasks together logically. Arguments assign a fixed expression or value to the identifier.

Providers achieve the configuration, and a Terraform registry accesses the Linode provider. A file with a .tf extension contains provider blocks and at least one resource block.

Here’s an example of how Terraform works in alliance with the Linode provider:

terraform {
 required_providers {
   linode = {
     source = "linode/linode"
     version = "1.16.0"
   }
  }
}

provider "linode" {
    token = "your-linode-api-token"
}

resource "linode_instance" "example_instance" {
    label = "example_instance_label"
    image = "linode/ubuntu20.04"
    region = "us-central"
    type = "g6-standard-1"
    root_pass = "your-root-password"
}

The above Terraform example with the file extension .tf showcases creating a solo Linode instance labeled as example_instance_label.

The example file has a mandatory provider block to help set up the Linode provider. You need to list it in your configuration to achieve the desired results. After the provider block, a resource declaration occurs. This declaration corresponds with your Linode infrastructure components, such as block storage volumes and Linode instances.

Type and region arguments define the instance type and region. Every Linode must also have a root password, and you can use the optional root_pass argument. If you skip assigning a password, Terraform generates a random password.

What is Pulumi?#

Pulumi is also a modern, fast-growing IaC solution. You can use it to maintain, deploy, and configure resources on your cloud infrastructure, as well as improve its efficiency.

It supports multiple private, hybrid, and public cloud providers such as OpenStack, Kubernetes, Google Cloud, Azure, Amazon Web Services (AWS), and phoenixNAP Bare Metal Cloud. You can use Pulumi to create infrastructure elements like networks, virtual machines, and databases.

Apart from creating traditional elements, Pulumi can also create modern cloud infrastructure components like serverless functions, clusters, and containers.

Pulumi accepts various imperative languages. The user defines the infrastructure state, and Pulumi creates the desired resources. In contrast to Terraform, Pulumi’s standout feature is that it allows you to create your infrastructure using a native programming language.

For example, here is a Python file’s code snippet for using Pulumi:

import pulumi
from pulumi_aws import s3

# Create an AWS resource (S3 Bucket)
bucket = s3.Bucket('my-bucket')

# Export the name of the bucket
pulumi.export('bucket_name', bucket.id)

The first part of the code imports Pulumi. Then, Pulumi’s AWS provider, pulumi_aws, imports S3. The following line instantiates the S3 bucket to save it in the bucket variable, and at the end, Pulumi exports the bucket.

You can use Pulumi just like any other Python package. Because of its imperative nature, you can create classes, write control flows, and build code blocks. If you are a developer at heart, you will enjoy working with Pulumi.

Terraform vs. Pulumi#

Now that we have a basic understanding of these two leading IaC solutions, let's discuss their significant differences. We have selected a few metrics to compare the IaC tools so that you can choose the best solution for your organization’s needs.

State management#

States files are important for enabling IaC tools to map the configuration requirements with available resources. Terraform stores the state files offline on the local drive in the terraform.tfstate file by default. In contrast, Pulumi allows you to create a free user account on their official website and store the state files online. However, you need to pay for Pulumi cloud services for any setup so that multiple developers can access the IaC tools.

Pulumi provides multiple functions, like a complete overview and insights into the resources and their deployment history with Pulumi. You can also access each deployment’s configuration details. These functions help effectively monitor, view, and manage Pulumi’s activities.

Suppose you purchase a team account with Pulumi. In that case, you receive a state locking mechanism and other features like integrating IaC tools with continuous integration and continuous deployment (CI/CD), Slack and Git integration, and team sharing.

To unlock all of these functions with Terraform, you can switch from the local drive and set up a Terraform cloud account. Alternatively, you can use a third-party provider. Keep in mind that you need to pay for the services on Terraform cloud if you have a team exceeding five members.

Ease of deployment#

By default, if you want to deploy components to the cloud infrastructure with Terraform, you need to use a SaaS platform. To deploy components from a local drive using Terraform, you need to add specific variables to the Terraform cloud ecosystem. However, with Pulumi, you can deploy resources from a local drive seamlessly.

If you are comfortable using a SaaS platform to deploy required components to your cloud infrastructure, use Terraform. Otherwise, Pulumi is a better option as you can deploy all the resources from your local drive without needing a SaaS platform.

Available documentation and community size#

Pulumi has limited documentation compared to Terraform. The best Pulumi resources are found on GitHub and within Pulumi’s Slack community. In comparison, Terraform’s website makes available all resources needed to use the tool to its maximum potential.

Community size is also a vital element when choosing an IaC tool. These communities usually have documentation and resources available to help you use the tool. Infrastructure administrators have widely used Terraform as an IaC tool for years, so it has a larger community size and greater popularity than Pulumi. Pulumi is more recent and is still improving and gaining popularity to match Terraform’s market cap.

Project structuring at scale#

Terraform helps you split projects into various modules and files. You can reuse these components for scalability and structuring large projects. You can also reuse code files for multiple purposes and environments. It simplifies structuring large projects and minimizes effort.

Pulumi structures the cloud infrastructure as micro-projects or monolithic projects. Every environment has a separate stack, making it challenging to structure larger projects. Additionally, you are unable to deserialize the stack reference into the resources while using high-level Pulumi extensions to map multiple resources.

Versatility#

Terraform supports several cloud providers. So, you can manage infrastructure across many cloud providers at once. Terraform also helps achieve the declarative configuration with short, clean code. You can embed any application in any language into your architecture.

With Pulumi, you can write the code using a programming language, enabling you to achieve your desired result with multiple parameters. There’s no limit to exploring the versatility of Pulumi’s IaC solution.

Conclusion#

Each IaC tool uses different approaches to achieve the same desired solution. Now that you know how these solutions perform within various criteria and situations, you can choose based on your requirements and goals.

Pulumi offers more flexibility and more focus on functions, while Terraform has better documentation and solid community support. Consider your cloud infrastructure and skillset when deciding.

Advancements in today’s IT environment have changed how DevOps and SREs provision infrastructure and manage processes. These advancements have created an environment with increased workflows, lines of code, and complications.

Transposit helps manage this complexity and empowers teams to run more consistent, secure IaC practices. Our simple user interface manages authentication and streamlines automation, reducing the reliance on experts and accelerating delivery.

To learn more about scaling your IaC practices with Transposit, request a demo.