Using IAM Roles to Write to S3 from AWS CLI

Introduction

This challenge demonstrates how to use AWS IAM roles and temporary credentials to allow a user (s3-support) to assume a role (S3WriteRole) and write files to a previously created S3 bucket. This is done exclusively using command-line tools (AWS CLI).

Objective

Set up an environment in AWS where:

• An IAM user with no direct permissions can assume a role with permissions to write to an S3 bucket.
• Access is achieved through temporary credentials using the AWS CLI.
• Diagram, explanation, and presentation of evidence for the process.

Steps Performed

1. Create S3 bucket The bucket named desafio3-lucas-s3 was created using the iamadmin profile:

2. Create IAM Role with Policies Creation of trust and permission policies (JSON):

s3_write_policy.json

trust_policy.json

Commands used:

Role:

Policy:

JSON Responses:

3. Add policy to rol

4. Create IAM user s3-support The following was generated:

• User: s3-support
• Programmatic credentials (access key + secret key)

5. Configure AWS CLI with the user

6. Asumir rol desde CLI y obtener credenciales temporales

Temporary credentials

7. Validate permissions by writing to the bucket