How are permissions granted for AWS Lambda to run code that can access the AWS API?

AWS Lambda functions require appropriate permissions to access AWS services and resources while executing code. The primary mechanism for granting these permissions is through AWS Identity and Access Management (IAM) roles.

When you create a Lambda function, you associate it with an IAM role that includes the necessary permissions. This role defines what actions the Lambda function can perform, such as reading from or writing to other AWS services like DynamoDB, S3, or API Gateway. The role essentially acts as a security identity that allows the Lambda function to access AWS resources securely.

This design is beneficial because it adheres to the principle of least privilege, enabling you to specify permissions explicitly for the Lambda function. Additionally, IAM roles can be easily updated to change permissions without needing to alter the Lambda function code itself, facilitating better management and security practices.

While Lambda permissions, encryption keys, and Lambda policies are relevant in the broader context of AWS security and management, they do not serve the same primary function as IAM roles in providing permissions specifically for Lambda to access AWS APIs.