This is who IAM

Tue, 27 May 2025 15:33:47 +0200

I. IAM: Core Components and Concepts

IAM is based on entities and policies.

IAM Entities

Users: Represent people or applications. Example: a developer named “alice”.
Groups: Collections of users sharing the same permissions.
Roles: IAM entities that can be temporarily assumed by others. Ideal for federation or services like EC2 or Lambda.
Policies: JSON documents that define permissions attached to an entity.

Sample JSON Policy

{
 "Version": "2012-10-17",
 "Statement": [
 {
 "Effect": "Allow",
 "Action": "s3:ListBucket",
 "Resource": "arn:aws:s3:::example_bucket"
 }
 ]
}

This IAM policy allows an AWS entity (user, role, or group) to list the objects in a specific S3 bucket named example_bucket. It uses the standard IAM version format (2012-10-17) and allows the s3:ListBucket action on the resource identified by its ARN. It lets the entity see the list of objects (names, sizes, metadata), but not read or modify them—unless additional permissions are granted. This minimal policy is often used for inventory or bucket navigation via the AWS Console or API.

IAM on Simple Enough Blog

This is who IAM

I. IAM: Core Components and Concepts

IAM Entities

Sample JSON Policy