Terraform vs. Pulumi: Which IaC Tool is Right for You?

Terraform vs Pulumi: Which IaC Tool is Right for You?

IaC has drastically evolved over the past couple of years in terms of how we manage and provision resources within our own infrastructure stacks. Moving away from manual processes, like configuring servers through the cloud’s console or running scripts for deployment, to code-driven infrastructure has made deploying and managing resources faster, more reliable, and easier to scale. However, as IaC has evolved, many tools have emerged, each with its own pros, cons, and learning curves suited to different project needs and requirements.

Two of the most widely discussed tools in the IaC space today are Terraform and Pulumi. Both aim to simplify infrastructure provisioning, management, and de-provisioning, but they take different approaches. Recently, discussions on platforms like Hacker News have highlighted the pros and cons of each tool. Some developers appreciate Terraform because of the clear, declarative syntax and its reliability in managing infrastructure across multiple cloud platforms, while others prefer Pulumi for its flexibility and use of familiar programming languages.

So, how do you decide which one to use for your team or project? Should you stick with the well-established Terraform, which is used by about 11% of developers, or should you try Pulumi, which offers a more programmatic approach and is currently used by around 0.82% of developers?

In this blog, we’ll compare Terraform and Pulumi, focusing on their key features, differences, and when to use each. We’ll also explore some real-world use cases and help you determine which tool is the best fit for your project. By the end, you’ll have a clear understanding of which tool to choose for your infrastructure needs.

How has IaC evolved over the past couple of years?

Before tools like Terraform, managing infrastructure often meant manually configuring resources through cloud consoles or using other tools. For example, AWS CloudFormation was a popular tool for IaC, but it only worked with AWS, which made it hard to use across different cloud providers like Azure and GCP. It also relied on YAML or JSON templates, which could be difficult to manage. Tools like Ansible, Chef, and SaltStack were good for managing configurations, but they didn’t fully automate infrastructure provisioning, leaving gaps in the process that we now expect to be automated.

When Terraform was introduced, it changed how we think about infrastructure. Terraform allowed infrastructure to be defined in simple, readable code and could manage resources across multiple cloud providers like AWS, Azure, or GCP. This made it easier for DevOps or Infrastructure engineers to automate and manage infrastructure using a standardized process. You only had to define the desired infrastructure, and Terraform would automatically provision and manage the resources to match that configuration.

As IaC tools improve, they make it easier to keep things consistent, automate tasks, and reduce errors. Now, there are more ways to customize your infrastructure to handle complex needs while still being reliable and efficient.

What is Terraform?

Terraform is an open-source tool used to manage cloud infrastructure. Its primary purpose is to define and provision infrastructure using code, which allows you to automate the creation, modification, and management of cloud resources. Whether you’re working with AWS, Azure, Google Cloud, or other major cloud providers now, Terraform makes it possible to control all aspects of your infrastructure in a consistent and repeatable way.

One of the key features of Terraform is its declarative syntax. Instead of writing scripts that tell the system exactly what steps to take, you simply define what you want your desired infrastructure state to look like, what resources you need, and the configurations for those resources. Terraform then takes care of figuring out the necessary steps to make your current infrastructure match the desired state. For example, if you need to set up a web server on AWS, you describe that server in a configuration file, and Terraform will automatically create and configure it for you.

Terraform interacts with cloud providers through providers. Providers are plugins that allow Terraform to manage resources for specific platforms. For example, the AWS provider allows you to manage AWS services like EC2 instances, S3 buckets, and Lambda functions. Similarly, providers exist for other cloud platforms like Azure and Google Cloud, making it easy to manage infrastructure across multiple cloud services and environments with a single IaC tool.

What are the advantages of Terraform?

As we’ve already discussed what Terraform is, let’s now look at the key advantages it offers:

• Declarative Language: Terraform’s declarative approach means you simply define what you want your infrastructure to look like rather than detailing how to create it. For example, you describe the desired resources, such as instances or databases, and their configurations using HashiCorp Configuration Language (HCL). Terraform then automatically figures out how to create and manage those resources. This makes the code easier to understand and reduces the chances of making mistakes, especially as your infrastructure grows.
• State Management: Terraform keeps track of the state of your infrastructure through a state file. This allows Terraform to know what resources exist, how they are configured, and what changes need to be made during future deployments. By tracking this state, Terraform can make sure that your infrastructure is always aligned with the desired configuration, even after multiple updates.

What are the challenges faced in Terraform?

Now, let’s take a closer look at some of its limitations:

• Limited Programming Flexibility: Terraform’s declarative nature makes it simple to use, but it falls short when it comes to building more complex infrastructure. It doesn’t handle advanced logic like loops, conditionals, or dynamic changes easily. While you can use workarounds like count or for_each, they’re not as flexible as programming languages like Python or JavaScript, which offer more control over complex logic. This limitation can make it difficult to build customized or highly dynamic infrastructure, especially when compared to using traditional programming languages.
• License Change to BSL: Terraform was originally fully open-source, but HashiCorp, the company behind it, changed its license to the Business Source License (BSL). While it still allows for open-source use, the BSL restricts commercial use of the tool, which limits businesses from Terraform unless they pay their new fee structure.

What are the use cases of Terraform?

Let’s take a look into some common use cases of Terraform:

• Policy Enforcement and Compliance Management: Terraform allows teams to create reusable modules for common configurations, such as security rules and network controls, ensuring consistency across environments. However, compliance and policy enforcement depend on the capabilities of the cloud provider being used. While Terraform can define the infrastructure, enforcing specific policies, like encryption or access controls, often relies on the cloud provider’s features. Tools like Open Policy Agent (OPA) can help enforce custom policies, but the effectiveness of these policies still depends on what the cloud provider supports.
• Disaster Recovery and Infrastructure Backups: Another important use case for Terraform is disaster recovery and infrastructure backup. By using Terraform’s state management and storing the state file in a remote backend, like AWS S3, you can make sure that your infrastructure is always backed up and can be easily restored in the event of any failure. Storing the state file in S3 allows you to version it, meaning every time a change is made to your infrastructure, it gets tracked. This makes it easy to roll back to a previous state if something goes wrong. For example, if an environment fails, you can quickly recreate it by applying your Terraform configuration again, pulling the latest state from S3. This ensures that you can easily restore the infrastructure to its exact configuration before failure, reducing downtime and minimizing data loss.

Hands-On: Deploying an EC2 Instance with Terraform

In this section, we’ll deploy an EC2 instance on AWS using Terraform. This will help you understand how to define Infrastructure as Code and automate the deployment of cloud resources with Terraform.

Prerequisite: Install Terraform on your machine by downloading it from the official website.

To get started, open your terminal and create a new directory for your Terraform project:

mkdir terraform-ec2
cd terraform-ec2

Define the required AWS provider and EC2 instance resource in your **main.tf **file:

provider "aws" {
  region = "us-east-1"
}

resource "aws_instance" "infra-instance" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"
  tags = {
    Name = "MyEC2Instance"
  }
}

Let’s break down the above Terraform code:

• Provider block sets up the AWS provider for the specified region.
• Resource block creates an EC2 instance using a specified Amazon Machine Image (AMI) and instance type.

Before you apply your configuration, initialize Terraform to download the necessary provider plugins by running the terraform init command:

Run the terraform plan command to preview the changes that Terraform will make:

Once you’ve reviewed the plan, apply the configuration to create the EC2 instance with terraform apply command:

By following these steps, you’ve successfully deployed an EC2 instance using Terraform, showcasing how infrastructure resources can be managed and provisioned as code.

What is Pulumi?

Pulumi is another popular IaC tool, but it takes a different approach than Terraform. While Terraform uses its own declarative language, Pulumi allows you to define your infrastructure using programming languages like Python, TypeScript, JavaScript, Go, and C#. This means that if you’re already familiar with one of these languages, you don’t have to learn a new language specifically designed for infrastructure, like HCL in Terraform. Instead, you can use the full power of familiar language and programming logic to define your infrastructure.

With Pulumi, you write infrastructure code the same way you would write regular application code. For example, you can use loops, conditionals, and other programming constructs to create your infrastructure. This gives you greater flexibility to manage complex infrastructures.

Pulumi allows you to create reusable abstractions using classes, functions, or modules to define common infrastructure components. This can include more complex configurations like virtual machines, networking setups, or managed storage systems. By using objects and classes, you can define these components at a higher level of abstraction, making your infrastructure code cleaner, more flexible, and easier to maintain. This advanced feature helps teams write less repetitive code and ensures consistency across different projects. Pulumi integrates seamlessly with development tools you’re already using, like IDEs, version control systems, and CI/CD pipelines, allowing you to manage both your application and infrastructure in a unified workflow.

What are the advantages of Pulumi?

Now that we know what Pulumi is, let’s take a look at its key advantages:

• Language Flexibility: One of Pulumi’s main benefits is that it lets you use programming languages you already know, like Python, TypeScript, or JavaScript, to manage your infrastructure. Instead of learning a new language or syntax for infrastructure, you can write infrastructure code just like you write application code. This makes it easier to integrate infrastructure with your application. For example, if you’re building an app with Python, you can use the same Python code to create and manage cloud resources like servers or databases. You can also use the same tools and libraries you’re already familiar with, like AWS SDKs or other application libraries, directly within your infrastructure code. This means you don’t have to switch between different environments or tools.
• Advanced Logic and Customization: Pulumi lets you use programming languages like Python or TypeScript for your infrastructure, which makes it easier to add complex logic. For example, you can create functions, use loops to build multiple resources or add conditionals to apply certain configurations only when needed. In other tools like Terraform, you’d need to use workarounds like count or for_each to do similar tasks. With Pulumi, you can directly use the programming language’s features, such as using libraries that are already part of your application.

What are the challenges faced in Pulumi?

While Pulumi offers many benefits, there are some limitations:

• Limited Community Support and Resources: Since Pulumi uses programming languages like Python or TypeScript, it can be more challenging for people who aren’t familiar with coding. For teams made up of non-developers or DevOps engineers who are used to declarative tools like Terraform, Pulumi’s approach might feel a bit complicated at first.
• Potential Complexity for Non-Developers: Since Pulumi allows developers to write infrastructure code in general-purpose programming languages like Python or TypeScript, it can be challenging for non-developers or teams who aren’t as familiar with programming. Without proper structure, the flexibility Pulumi offers could lead to more complex code that is harder to maintain, especially in larger teams with varying levels of technical expertise. This could result in difficulties with long-term maintenance or onboarding new team members.

What are the use cases of Terraform?

Let’s take a look at some common use cases for Pulumi.

• Infrastructure Deployment by Application Developers: In teams where there isn’t a dedicated DevOps engineer, application developers often need to manage and deploy infrastructure themselves. Pulumi simplifies this process by allowing developers to define infrastructure like servers, databases, and networks directly in the same codebase as their application. This makes it easier for developers to deploy and manage infrastructure alongside their application code, without needing to rely on external infrastructure specialists. By integrating infrastructure management within the same development workflow, teams can move faster and maintain everything in one place.
• Using Existing Code and Tools: Since Pulumi uses common programming languages like Python and TypeScript, you can use the same libraries and tools you already use to build your app. For example, if you’re working with AWS, you can use the AWS SDK or other tools directly in your Pulumi scripts. This makes it easier to work with the tools you’re familiar with and cuts down on the need for extra code or configuration.

These are some of the main reasons Pulumi is ideal for teams that are already familiar with programming languages and want to manage their infrastructure in a more flexible and integrated way.

Hands-On: Deploying an S3 bucket with Pulumi

In this section, we’ll create an S3 bucket using Pulumi with TypeScript. The process is simple, and you’ll see how to integrate your infrastructure into your existing code workflow.

Firstly, make sure that you have Pulumi installed. You can install it via npm:

npm install -g pulumi

Now, in your terminal, create a new Pulumi project using the following commands:

mkdir pulumi-s3-demo
cd pulumi-s3-demo
pulumi new typescript

Next, we need the AWS SDK to interact with AWS services. You can install it with npm:

npm install @pulumi/aws

In your index.ts file, write the following code to create an S3 bucket:

import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

const bucket = new aws.s3.Bucket("terrateam-bucket-0838995", {
    acl: "private",
});

export const bucketName = bucket.id;

This code:

• Imports the necessary Pulumi and AWS modules.
• Creates an S3 bucket with a private ACL.
• Exports the bucket’s ID as output so that you can reference it later.

Now that your code is written, you can run the pulumi preview command to preview the changes:

If everything looks good, you can deploy the infrastructure by running the pulumi up command.

By following these steps, you’ve successfully created an S3 bucket using Pulumi with TypeScript, integrating your infrastructure with your application code.

Key Differences Between Terraform and Pulumi

In this section, we’ll explore some key differences between Terraform and Pulumi. While both tools aim to simplify infrastructure management, they have distinct approaches when it comes to configuration, multi-cloud support, and programming language usage. The table highlights these differences to help you better understand how both tools work and which might be the best fit for your project.

Choosing the Right Tool: Key Decision Factors

When deciding between Terraform and Pulumi, there are several factors to consider that can help guide your decision. Each tool has its strengths, and understanding your team’s needs and project requirements can help you choose the best option.

• Skill Set Within the Team: If your team is already experienced with general-purpose programming languages like Python or TypeScript, Pulumi may be a natural fit. On the other hand, if your team is more comfortable with declarative infrastructure-as-code tools and doesn’t have extensive programming experience, Terraform might be the better choice.
• Community Support: Both Terraform and Pulumi have active communities, but Terraform has been around for longer and has a more developed ecosystem. If you’re looking for a lot of resources, tutorials, or support from other users, Terraform’s larger community can be a great help. However, Pulumi’s community is growing and may appeal to developers who like using common programming languages like Python or TypeScript.
• Project Complexity and Logic Requirements: If your project requires complex infrastructure setups with advanced logic, Pulumi’s ability to use general-purpose programming languages can give you the flexibility needed. This includes adding loops, conditionals, and using objects, classes, libraries, or existing code in your infrastructure code. However, if your project is relatively straightforward and you value simplicity and stability, Terraform’s declarative approach might be more beneficial.

Ultimately, the choice between Terraform and Pulumi comes down to your team’s skill set, project complexity, and the domain specific language features you need, so carefully evaluating these factors will help you make the right decision for your infrastructure management needs.

Security and Compliance Considerations

Now, when it comes to managing infrastructure through IaC, security and compliance should always be at the forefront of your mind. As your infrastructure grows, ensuring it remains secure and compliant becomes increasingly challenging. Both Terraform and Pulumi offer tools and practices to help enforce security and meet compliance requirements, but how do you make sure you’re following best practices?

In this section, we’ll explore some key security considerations for managing your IaC:

• Access Control: Access control is all about making sure that only the right people can make changes to your infrastructure. Both Terraform and Pulumi allow you to control who has access to what. With Terraform, you can use cloud IAM systems like AWS IAM or Azure AD to define who can modify resources. Pulumi works similarly, letting you control access through cloud RBAC (role-based access control). By setting these permissions, you make sure that only authorized users can change your infrastructure.
• Secrets Management: Both Terraform and Pulumi provide ways to handle sensitive data securely, but their approaches vary. In Terraform, secrets can be retrieved from external tools like HashiCorp Vault or AWS Secrets Manager using providers like Vault or secretsmanager. These secrets are not hardcoded in the code and can be marked as sensitive to avoid exposure in the output. However, care must be taken to ensure they don’t appear in the state files or logs. Pulumi works similarly by integrating with secret management tools and using the Secret type to encrypt and protect sensitive values in its state file. Both tools ensure that secrets are securely managed and encrypted, but you need to follow best practices to prevent accidental exposure in logs or outputs.
• Policy Enforcement: Ensuring compliance can be automated by using policy-as-code. In Terraform, tools like Sentinel allow you to define rules that your infrastructure must follow. For example, you can create policies that require encryption on all data or ensure specific ports are closed. Pulumi can enforce similar rules using Open Policy Agent (OPA), giving you control over what is allowed or disallowed in your infrastructure. These tools make sure that your infrastructure meets security standards without needing manual checks.
• Audit and Change Tracking: Tracking changes and maintaining an audit trail is important for security and compliance. With Terraform, you can use version control systems like Git and store your state files in remote backends like AWS S3. This keeps a record of all changes and allows you to roll back to previous configurations if needed. Pulumi also integrates with version control and keeps a record of every change made to your infrastructure. Both tools can be connected to logging systems , like AWS CloudTrail, to monitor and track all infrastructure changes, making audits and tracking much easier.

By using these security considerations with Terraform or Pulumi, you can make sure that your infrastructure remains secure, compliant, and well-managed.

However, when using vanilla Terraform, you may realize that it doesn’t fully address all security and compliance needs out-of-the-box. For example, managing access control, secrets, and policies often requires custom code, which can be time-consuming and hard to maintain. Without additional tools or custom logic, ensuring compliance across environments becomes more challenging, especially as your infrastructure scales. This is where Terrateam comes in.

Introducing Terrateam

Terrateam is built to enhance Terraform by handling security and compliance more easily. While Terraform is great for managing infrastructure, it doesn’t provide all the tools needed to manage access control, secrets, and policies by itself. Terrateam solves this problem, making it simpler to manage infrastructure securely.

With Terrateam, you get useful features like role-based access control (RBAC), automated policy enforcement, secrets management, and audit logging. These features ensure that your infrastructure remains secure, compliant, and easy to manage as it grows. Terrateam works with Terraform to make managing security and compliance simpler, without needing extra tools or complex code.

Role-Based Access Control (RBAC)

Terrateam’s Role-Based Access Control (RBAC) allows you to control who can perform Terraform actions like terrateam plan or terrateam apply on your infrastructure. By assigning specific roles to users, you can make sure that only authorized developers can make changes. This reduces the risk of accidental or unauthorized changes. For example, you can give plan permissions to developers and apply permissions to admins, ensuring that only the right people can make critical changes.

This helps you enforce the principle of least privilege, where users only have access to what they need. With this level of control, you can make sure that everyone has the correct permissions based on their role, keeping your infrastructure secure and compliant.

For more details, visit Role-Based Access Control

Policy Enforcement

You can easily integrate OPA into your Terrateam workflow to ensure compliance by adding policy checks on each plan operation. These checks verify that all changes meet your defined rules before they are deployed. For example, using the conftest-wrapper in your .terrateam/config.yml file, you can automatically apply policies related to security, resource usage, or any custom rules.

For more details, visit Policy enforcement with OPA.

Secrets Management

Terrateam simplifies secret management by securely handling sensitive data such as API keys, login tokens, and passwords. With Terrateam, you can manage secrets in various ways, including environment variables, GitHub secrets, and tfvars files. This ensures that sensitive data never appears in plain text within your Terraform code or version control.

You can use GitHub Secrets to define environment variables that are automatically converted into lowercase names in the Terrateam runtime. This integration makes it easier to securely pass variables to your Terraform configuration without compromising security. Additionally, Terrateam allows you to use .tfvars files to customize your configurations securely without exposing sensitive data to the code.

For more details, visit Secrets and Variables

Audit Logging

Terrateam, which also provides a comprehensive audit trail feature that logs all infrastructure changes and activities for complete transparency. Here, every pull request, plan, apply, and drift detection is tracked, showing details such as the user who initiated the action, the time of execution, and the result of the operation.

This detailed logging allows teams to track changes, identify issues, and maintain compliance standards across their organization. By having a complete history of the actions taken, teams can easily audit infrastructure changes and make sure everything is properly managed and accounted for before it causes any incidents.

For more, visit Terrateam Audit Trail.

With Terrateam, managing and securing your infrastructure becomes much easier. It provides key features like role-based access control, policy enforcement, secrets management, and audit logging to help you stay compliant and secure. Terrateam works smoothly with Terraform, making sure you can focus on building your infrastructure without worrying about complex security setups. Become a part of the next IaC revolution using Terrateam and keep your infrastructure secure and well-managed as it grows.

Conclusion

By now, you should have a clear idea of what Terraform and Pulumi can do and how each one fits different needs. Whether you value simplicity or need more flexibility, choosing the right tool is important for managing your infrastructure well. Both IaC tools are powerful, but following best practices will help you improve your developer productivity, keeping your infrastructure secure and efficient.