Cross-Account Access to Amazon S3 | AWS IAM

2 min read 6 months ago
Published on Apr 21, 2024 This response is partially generated with the help of AI. It may contain inaccuracies.

Table of Contents

Step-by-Step Tutorial: Cross-Account Access to Amazon S3 using AWS IAM

  1. Create a User in Account A:

    • In Account A, create a user named Jack with a role in DCT Production.
    • Assign an external ID to the role in DCT Production.
    • Ensure the role has a trust policy and permissions policy to allow access to an S3 bucket.
  2. Generate Access Keys for User Jack:

    • Create an access key and a secret access key for User Jack.
    • Save these keys securely for future use.
  3. Attach User Policy to User Jack:

    • Attach the user policy to the username Jack using the policy ARN.
  4. Create Access Keys for User Jack:

    • Retrieve the access key ID and secret access key for User Jack.
    • Store these values securely for future use.
  5. Assume Role in Account B:

    • Log in to the AWS Management Console of Account B.
    • Create a role with a trust relationship with Account A.
    • Specify the account ID of Account A and an external ID for security.
  6. Run Assume Role Command:

    • Copy the command provided in the AWS Management Console.
    • Execute the command to assume the role in Account B.
  7. Set Environment Variables:

    • Copy the access key ID, secret access key, and session token from the assume role command.
    • Set these values as environment variables in your CLI.
  8. Test Access to S3 Bucket:

    • Run AWS CLI commands without specifying a profile.
    • Ensure that you can access and interact with S3 buckets in Account B.
  9. Cleanup:

    • If needed, delete any resources or buckets created during the tutorial.
    • Unset the environment variables to revert to your main account settings.
  10. Next Steps - Using IAM Roles with EC2:

    • Consider exploring the next lesson on using IAM roles with EC2 instances for enhanced security and access control.

By following these steps, you will be able to set up cross-account access to Amazon S3 using AWS IAM and effectively manage permissions and roles between different AWS accounts.