AWS CLI vs AWS CloudFormation: What are the differences?

Introduction

In this article, we will discuss the key differences between AWS CLI (Command Line Interface) and AWS CloudFormation, two widely used services offered by Amazon Web Services (AWS).

1. Deployment and Infrastructure Management: AWS CLI is a command-line tool that allows developers to interact with various AWS services by typing in commands. It enables users to perform tasks like managing Amazon S3 buckets, launching EC2 instances, and configuring security policies. On the other hand, AWS CloudFormation is a service that enables users to create and manage a collection of AWS resources using a template. It provides a declarative way to define infrastructure as code and automates the provisioning and updating of resources.

2. Level of Abstraction: AWS CLI provides a low-level interface, allowing users to directly interact with individual AWS services and resources. It requires a detailed understanding of the underlying AWS service APIs and their parameters. In contrast, AWS CloudFormation offers a high-level abstraction that simplifies the provisioning and management of AWS resources. It allows users to define Infrastructure as Code (IaC) using a JSON or YAML template, abstracting away much of the complexity of the underlying infrastructure.

3. Flexibility and Customization: AWS CLI provides full control and flexibility, allowing users to construct complex workflows by scripting multiple commands together. This level of control enables users to perform custom operations and automate intricate tasks. AWS CloudFormation, on the other hand, is designed to provide a standard and consistent way to manage infrastructure resources. While it supports limited customization using intrinsic functions and conditional statements, it promotes standardized infrastructure provisioning and management.

4. Orchestration and Rollbacks: AWS CLI lacks built-in orchestration capabilities to manage the provisioning and configuring of multiple resources as a single unit. It requires manual coordination to ensure the correct order and dependencies are maintained. In contrast, AWS CloudFormation offers orchestration features that simplify the management and coordination of multiple resources. It supports automated provisioning, updating, and deletion of resources, and enables rollbacks in case of failures during stack updates.

5. Discoverability and Documentation: AWS CLI makes it relatively easy to discover available services, commands, and their options using auto-completion and interactive documentation. It provides detailed help and examples for each command, making it an efficient tool for exploration and learning. On the other hand, AWS CloudFormation templates require familiarity with the AWS CloudFormation Resource Specification and the available resource types and properties. While CloudFormation has a rich set of documentation, it may have a steeper learning curve compared to AWS CLI.

6. Portability and Stack Management: AWS CLI requires users to manually manage different versions of configuration files for each environment. It lacks built-in capabilities to manage and track changes to infrastructure over time. In contrast, AWS CloudFormation supports the creation of stack templates, enabling consistent and repeatable infrastructure deployments. It allows users to version and manage their infrastructure as code, making it portable and facilitating collaboration among team members.

In summary, AWS CLI provides a command-line interface for low-level interaction with individual AWS services, while AWS CloudFormation offers a higher-level abstraction for managing infrastructure as code. AWS CLI offers more flexibility and customization options, but CloudFormation simplifies infrastructure provisioning and offers built-in orchestration features. Both services have their strengths and are often used together to achieve specific automation and management requirements.