1.5.1. AWS CLI (Command Line Interface)

First Principle: The AWS CLI empowers developers to manage AWS services and automate tasks via simple commands, accelerating development workflows and enabling scripting.

The AWS Command Line Interface (CLI) is a unified tool that allows developers to manage their AWS services from the command line. It provides direct access to the public AWS API, enabling scripting, automation, and quick interactions with AWS.

• Quick Operations: Create an S3 bucket, launch an EC2 instance, list Lambda functions quickly.
• Scripting Automation: Automate repetitive development tasks, such as deploying application artifacts, updating Lambda function configurations, or managing DynamoDB table settings.
• Integration with CI/CD: Used in automated build and deployment scripts.
• Debugging: Retrieve logs, check resource status, or inspect resource configurations directly from the terminal.

Scenario: You need to automate the deployment of new Lambda function versions and update their associated API Gateway endpoints as part of a development script.

⚠️ Exam Trap: The AWS CLI uses the same API calls as the SDK and Console. If an action works in the Console but fails via CLI, the issue is almost always IAM permissions or credential configuration — not a CLI limitation.