aws-whoami

Find what AWS account and identity you're using

⚠️ This is the successor to the python implementation as a CLI tool. The other is still useful as a Python library.

You should know about aws sts get-caller-identity, which sensibly returns the identity of the caller. But even with --output table, I find this a bit lacking. That ARN is a lot to visually parse, it doesn't tell you what region your credentials are configured for, and I am not very good at remembering AWS account numbers. aws-whoami makes it better.

$ aws-whoami
Account:         123456789012
                 my-account-alias
Region:          us-east-2
AssumedRole:     MyRole
RoleSessionName: ben
UserId:          AROASOMEOPAQUEID:ben
Arn:             arn:aws:sts::123456789012:assumed-role/MyRole/ben

Note: if you don't have permissions to iam:ListAccountAliases, your account alias won't appear. See below for disabling this check if getting a permission denied on this call raises flags in your organization.

Install

go install github.com/benkehoe/aws-whoami-golang/v2/aws-whoami@latest

Or download the latest release for your platform.

Options

aws-whoami uses the AWS Go SDK v2, so it'll pick up your credentials in the normal ways, including with the --profile parameter.

If you'd like the output as a JSON object, use the --json flag. See below for field names.

The --disable-account-alias flag disables account alias checking (see below).

Use --version to output the version.

Account alias checking

By default, aws-whoami calls the IAM ListAccountAliases API to find the account name, if set. If you don't have access to this API (the iam:ListAccountAliases IAM action), it swallows that error. In general this is fine, but if it causes trouble (e.g., raising security alerts in your organization), you can disable it.

There are two ways to disable account alias checking. The first is the --disable-account-alias flag. The second, setting the environment variable AWS_WHOAMI_DISABLE_ACCOUNT_ALIAS, allows for persistent and selective control.

To fully disable account alias checking, set AWS_WHOAMI_DISABLE_ACCOUNT_ALIAS to true. To selectively disable it, you can also set the value to a comma-separated list where each item will be matched against the following:

The beginning or end of the account number
The principal name or ARN
The role session name
The SSO role (permission set) name

JSON output

The JSON object that is printed when using the --json flag always (when successful, see below for errors) includes the following fields:

Account
AccountAliases (NOTE: this is a list)
Arn
Type
Name
RoleSessionName
UserId
Region
SSOPermissionSet

Type, Name, and RoleSessionName (and SSOPermissionSet) are split from the ARN for convenience. RoleSessionName is null for IAM users. For the account root, both the Type and Name are "root".

SSOPermissionSet is set if the assumed role name conforms to the format AWSReservedSSO_{permission-set}_{random-tag}, otherwise it is null.

Note that the AccountAliases field is an empty list when account alias checking is disabled, not null.

If there is an error, a JSON object is printed with the following structure: {"Error": "The error message"}

AWS CLI alias

The AWS CLI has a way to add command aliases, and you can use this with aws-whoami. In ~/.aws/cli/alias, add whoami = !aws-whoami under the [toplevel] section, like this:

[toplevel]

whoami = !aws-whoami

Now you can run the command aws whoami as if it was part of the AWS CLI.

Of course, even if you're not using aws-whoami you can create aws whoami as an alias for GetCallerIdentity directly, like this:

[toplevel]

whoami = sts get-caller-identity --output table

benkehoe / aws-whoami-golang