Introduction

When it comes to automating cloud infrastructure, Infrastructure as Code(IaC) tools like CloudFormation and Terraform are always the top choices. These tools can automatically deploy and manage resources on a cloud platform. But which one is the best option? In this post, we will be comparing the two popular IaC tools, CloudFormation and Terraform, highlighting their key advantages and limitations.

CloudFormation vs Terraform

CloudFormation

AWS CloudFormation is a managed service that provides infrastructure as code to AWS customers. It provisions AWS resources and the entire stack required to run your applications. CloudFormation allows users to define templates as code to create and manage AWS resources, applications, and services in a safe and repeatable way.

Advantages

• Native support for AWS resources: CloudFormation is designed to integrate with AWS services, so users do not need to define resources and their dependencies manually. With over 500 AWS resources available within CloudFormation, it supports a wide variety of workloads.

• Native support for AWS services: CloudFormation has native support for AWS services such as Elastic Beanstalk and Opsworks enabling users to automate and manage infrastructure related to those services in a single deployment template.

• Customizable Rollbacks: CloudFormation supports customizable automatic rollbacks, allowing users to revert to a previous stack state in case of a failed deployment.

Limitations

• Limited Multi-cloud support: CloudFormation is tightly integrated with AWS, and its templates are specific to the AWS cloud. It does not provide support for working across multiple cloud providers.

• No dedicated testing capability: It currently lacks a robust infrastructure testing framework making it challenging to perform testing during the development cycle.

• Limit on the number of resources per stack: Although this is not necessarily a limitation, it's worth noting that there is a hard limit of 500 resources per AWS CloudFormation stack, after which users must create and manage additional stacks.

Terraform

Terraform, an open-source tool created by Hashicorp, enables users to provision infrastructure for various cloud providers, including AWS, Azure, and Google Cloud Platform (GCP). It defines an abstraction layer, enabling users to easily provision multiple resources using high-level configuration files, which can then be automatically deployed.

Advantages

• Multi-Cloud Support: Terraform provides support for multiple cloud providers, which enables users to deploy and manage workloads across different clouds. Terraform supports more than 100 cloud providers, making it suitable for enterprises that operate on multiple cloud vendors.

• Modularity: Terraform features a highly modular infrastructure, allowing users to separate infrastructure concerns into separate files for more straightforward management.

• Testing Support: Terraform provides support for infrastructure testing, enabling users to ensure their infrastructure installations are working correctly before deployment.

Limitations

• Steep Learning Curve: Terraform's integration can be challenging to set up, requiring more than basic knowledge of cloud infrastructure to use effectively.

• Slow deployment & resource provisioning times: Terraform's deployment time is relatively slow when compared to other IaC tools. This issue could be problematic for deployment scenarios that require rapid scale-out.

• Lack of granular access controls: Terraform's lack of fine-grained access controls can be a concern in enterprise settings where strict security and access controls are critical.

Comparison

The following table highlights the key differences between CloudFormation and Terraform:

Conclusion

Both CloudFormation and Terraform are high-quality infrastructure as code tools, and the best choice will depend on the specific requirements and capabilities of your organization. If you intend to deploy and manage resources exclusively on AWS, CloudFormation is the better choice, while Terraform is a suitable option for those who prefer a multi-cloud environment. That said, developers using either of the tools should be well versed in the specific requirements to achieve maximum benefits.

References

• AWS CloudFormation - https://aws.amazon.com/cloudformation/
• Terraform - https://www.hashicorp.com/products/terraform
• AWS Certified DevOps Engineer (Professional) Exam Study Guide - by Brett McLaughlin.