Bucket Policy

Bucket Policy is a set of rules that define how objects are accessed in an S3 bucket. It helps in managing permissions and access control for your objects stored in the bucket.

Key Components

• Statement: Defines a set of permissions for a user or group.
• Principal: The entity that can be granted permissions (e.g., AWS account, IAM user, or role).
• Action: The operations that are allowed or denied on the bucket or objects within the bucket.
• Resource: The bucket or object(s) to which the policy applies.

Example Policy

Here's an example of a bucket policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::123456789012:root"
            },
            "Action": [
                "s3:GetObject",
                "s3:ListBucket"
            ],
            "Resource": [
                "arn:aws:s3:::mybucket/*",
                "arn:aws:s3:::mybucket"
            ]
        }
    ]
}

In this example, the policy allows the AWS account 123456789012:root to perform GetObject and ListBucket actions on all objects and the bucket mybucket.

Best Practices

• Always follow the principle of least privilege when granting permissions.
• Regularly review and update your bucket policies to ensure they meet your current requirements.
• Use IAM roles instead of IAM users to grant permissions when possible.
• Enable logging and monitoring to keep track of bucket access and detect any unauthorized activities.

For more information, please refer to the Amazon S3 Bucket Policy documentation.