Introduction to AWS IAM

Introduction

AWS Identity and Access Management (IAM) is a web service that helps you securely control access to AWS resources. With IAM, you can manage users, groups, and roles, and define permissions to allow or deny access to AWS services. In this article, we’ll explore the key concepts of IAM and provide examples of how to manage IAM users, groups, and roles.

Prerequisites

To follow along, you should have a basic understanding of:

• AWS services
• Security best practices
• AWS Management Console

Key Concepts

Users

IAM users are individuals or services that need access to AWS resources. Each user has a unique set of credentials and permissions.

Groups

IAM groups are collections of users that share the same permissions. Groups make it easier to manage permissions for multiple users.

Roles

IAM roles are used to grant permissions to AWS services or users from other AWS accounts. Roles are temporary and do not have long-term credentials.

Policies

IAM policies are JSON documents that define permissions. Policies can be attached to users, groups, or roles to grant or deny access to AWS resources.

Setting Up IAM Users

Creating a User

To create a new IAM user, follow these steps:

1. Open the IAM Console.
2. In the navigation pane, choose “Users” and then “Add user”.
3. Enter a username and select the type of access (programmatic access, AWS Management Console access, or both).
4. Attach policies directly or add the user to a group with the required permissions.
5. Review and create the user.

Example: Creating a User with AWS CLI

aws iam create-user --user-name JohnDoe
aws iam create-access-key --user-name JohnDoe

Managing IAM Groups

Creating a Group

To create a new IAM group, follow these steps:

1. Open the IAM Console.
2. In the navigation pane, choose “Groups” and then “Create New Group”.
3. Enter a group name and attach policies to the group.
4. Review and create the group.

Example: Creating a Group with AWS CLI

aws iam create-group --group-name Developers
aws iam attach-group-policy --group-name Developers --policy-arn arn:aws:iam::aws:policy/AmazonS3FullAccess

Adding Users to a Group

To add users to a group, follow these steps:

1. Open the IAM Console.
2. In the navigation pane, choose “Groups” and select the group.
3. Choose the “Users” tab and then “Add Users to Group”.
4. Select the users to add and choose “Add Users”.

Example: Adding Users to a Group with AWS CLI

aws iam add-user-to-group --group-name Developers --user-name JohnDoe

Creating and Managing IAM Roles

Creating a Role

To create a new IAM role, follow these steps:

1. Open the IAM Console.
2. In the navigation pane, choose “Roles” and then “Create role”.
3. Select the type of trusted entity (AWS service, another AWS account, or web identity).
4. Attach policies to the role.
5. Review and create the role.

Example: Creating a Role with AWS CLI

aws iam create-role --role-name LambdaExecutionRole --assume-role-policy-document file://trust-policy.json
aws iam attach-role-policy --role-name LambdaExecutionRole --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

Trust Policy Example

Create a file named trust-policy.json with the following content:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

Best Practices for IAM

1. Use Least Privilege: Grant only the permissions necessary for users to perform their tasks.
2. Enable MFA: Enable multi-factor authentication for added security.
3. Rotate Credentials: Regularly rotate access keys and passwords.
4. Use Roles for Applications: Use IAM roles instead of long-term credentials for applications running on AWS services.
5. Monitor IAM Activity: Use AWS CloudTrail to monitor and log IAM activity.

Conclusion

AWS IAM is a powerful tool for managing access to AWS resources. By understanding and implementing IAM best practices, you can secure your AWS environment and ensure that users have the appropriate permissions to perform their tasks. Experiment with IAM to see how it can benefit your projects.

Further Reading

• AWS IAM Documentation
• AWS IAM Best Practices
• AWS CLI IAM Commands