IAM Policy
A JSON document that defines permissions for AWS resources.
Description
An IAM Policy in the context of AWS (Amazon Web Services) is a document written in JSON (JavaScript Object Notation) that specifies the permissions granted to users, groups, or roles within an AWS account. These policies can allow or deny access to various AWS services and resources, enabling fine-grained control over who can perform specific actions. IAM Policies consist of statements that define actions, resources, and conditions under which the actions are allowed or denied. For example, an IAM Policy can grant a developer the ability to launch EC2 instances while restricting their access to delete those instances. Policies are crucial for implementing security best practices in AWS, as they ensure that users have only the permissions necessary to perform their jobs, following the principle of least privilege. Additionally, AWS provides managed policies, which are pre-defined policies that can be easily attached to users or roles, simplifying the management of permissions across the AWS environment.
Examples
- An IAM Policy that allows a user to read objects in an S3 bucket, while denying the ability to delete them.
- An IAM Policy that grants a developer permission to create and manage Lambda functions but restricts access to billing information.
Additional Information
- IAM Policies can be attached to IAM users, groups, or roles, allowing flexible permission management.
- AWS provides a Policy Simulator tool to test and troubleshoot IAM Policies before applying them.