Introduction to AWS Identity and Access Management (IAM)

Introduction

AWS Identity and Access Management (IAM) is a service that helps you securely control access to your AWS resources. IAM enables you to manage users, groups, and permissions for those users and groups. This tutorial will introduce you to the basics of IAM, focusing on roles, policies, and permissions.

Concepts

Users

In IAM, a user is an entity that can access AWS services. Users can be individuals or applications. Each user has a unique username and credentials (access key ID and secret access key) that they use to authenticate with AWS.

Groups

A group in IAM is a collection of users. You can assign permissions to a group, and all users in the group inherit those permissions. This makes it easier to manage permissions for multiple users at once.

Roles

A role in IAM is an entity that you can create in your account that has specific permissions. A role does not have associated credentials (such as access keys). Instead, it is assumed by another AWS service or a user within the same AWS account. Roles are commonly used for cross-service access and temporary access.

Policies

A policy in IAM is a document that defines what actions are allowed or denied on specific resources. Policies can be attached to users, groups, roles, or even individual AWS resources. Policies are written in JSON format and specify which actions (like s3:GetObject) are permitted or denied on which resources (like an S3 bucket).

Permissions

Permissions in IAM refer to the ability to perform specific actions on AWS resources. These permissions are defined by policies attached to users, groups, roles, or resources.

Examples

Let's walk through some practical examples to understand how these concepts work together.

Creating a User and Attaching a Policy

1. Create a New User:

   First, you need to create a new user in the AWS Management Console.

   • Go to the IAM console.
   • Click on "Users" in the left-hand menu.
   • Click on "Add user".
   • Enter a username and select "Programmatic access" as the access type.
   • Click "Next: Permissions".
   • Select "Attach existing policies directly" and choose a policy like AmazonS3ReadOnlyAccess.
   • Click "Next: Tags", then "Next: Review", and finally "Create user".

2. Using the User Credentials:

   After creating the user, you will receive an access key ID and secret access key. You can use these credentials to authenticate with AWS services.

   Terminal

   aws configure

   AWS Access Key ID [None]: YOUR_ACCESS_KEY_ID
   AWS Secret Access Key [None]: YOUR_SECRET_ACCESS_KEY
   Default region name [None]: us-west-2
   Default output format [None]: json
   

3. Accessing S3 with the New User:

   Now, you can use the new user's credentials to access an S3 bucket.

   Terminal

   aws s3 ls

   Output

   2023-10-01 12:34:56 my-bucket

Creating a Role and Attaching a Policy

1. Create a New Role:

   • Go to the IAM console.
   • Click on "Roles" in the left-hand menu.
   • Click on "Create role".
   • Select the type of trusted entity (e.g., AWS service).
   • Choose the service that will assume this role (e.g., EC2).
   • Click "Next: Permissions".
   • Attach a policy like AmazonEC2FullAccess.
   • Click "Next: Tags", then "Next: Review".
   • Enter a name for the role and click "Create role".

2. Using the Role in an EC2 Instance:

   You can now launch an EC2 instance with this role, allowing it to perform actions defined by the attached policy.

What's Next?

Now that you have a basic understanding of IAM roles, policies, and permissions, you can explore more advanced topics such as managing access for AWS services, using IAM with AWS Lambda, or implementing fine-grained access controls. In the next section, we will dive deeper into Amazon EC2, exploring how to launch and manage instances.

Stay tuned for more tutorials on AWS services!