How AWS Billing Conductor works with IAM

Before you use IAM to manage access to Billing Conductor, you should understand what IAM features are available to use with Billing Conductor. To get a high-level view of how Billing Conductor and other AWS services work with IAM, see AWS Services That Work with IAM in the IAM User Guide.

Billing Conductor identity-based policies

With IAM identity-based policies, you can specify allowed or denied actions and resources as well as the conditions under which actions are allowed or denied. Billing Conductor supports specific actions, resources, and condition keys. To learn about all of the elements that you use in a JSON policy, see IAM JSON Policy Elements Reference in the IAM User Guide.

Actions

Administrators can use AWS JSON policies to specify who has access to what. That is, which principal can perform actions on what resources, and under what conditions.

The Action element of a JSON policy describes the actions that you can use to allow or deny access in a policy. Policy actions usually have the same name as the associated AWS API operation. There are some exceptions, such as permission-only actions that don't have a matching API operation. There are also some operations that require multiple actions in a policy. These additional actions are called dependent actions.

Include actions in a policy to grant permissions to perform the associated operation.

Policy actions in Billing Conductor use the following prefix before the action: Billing Conductor:. For example, to grant someone permission to run an Amazon EC2 instance with the Amazon EC2 RunInstances API operation, you include the ec2:RunInstances action in their policy. Policy statements must include either an Action or NotAction element. Billing Conductor defines its own set of actions that describe tasks that you can perform with this service.

To specify multiple actions in a single statement, separate them with commas as follows:

"Action": [
      "ec2:action1",
      "ec2:action2"

You can specify multiple actions using wildcards (*). For example, to specify all actions that begin with the word Describe, include the following action:

"Action": "ec2:Describe*"

To see a list of Billing Conductor actions, see Actions Defined by AWS Billing Conductor in the IAM User Guide.

Resources

Administrators can use AWS JSON policies to specify who has access to what. That is, which principal can perform actions on what resources, and under what conditions.

The Resource JSON policy element specifies the object or objects to which the action applies. Statements must include either a Resource or a NotResource element. As a best practice, specify a resource using its Amazon Resource Name (ARN). You can do this for actions that support a specific resource type, known as resource-level permissions.

For actions that don't support resource-level permissions, such as listing operations, use a wildcard (*) to indicate that the statement applies to all resources.

"Resource": "*"

The Amazon EC2 instance resource has the following ARN:

arn:${Partition}:ec2:${Region}:${Account}:instance/${InstanceId}

For more information about the format of ARNs, see Amazon Resource Names (ARNs) and AWS Service Namespaces.

For example, to specify the i-1234567890abcdef0 instance in your statement, use the following ARN:

"Resource": "arn:aws:ec2:us-east-1:123456789012:instance/i-1234567890abcdef0"

To specify all instances that belong to a specific account, use the wildcard (*):

"Resource": "arn:aws:ec2:us-east-1:123456789012:instance/*"

Some Billing Conductor actions, such as those for creating resources, cannot be performed on a specific resource. In those cases, you must use the wildcard (*).

"Resource": "*"

Many Amazon EC2 API actions involve multiple resources. For example, AttachVolume attaches an Amazon EBS volume to an instance, so an IAM user must have permissions to use the volume and the instance. To specify multiple resources in a single statement, separate the ARNs with commas.

"Resource": [
      "resource1",
      "resource2"

To see a list of Billing Conductor resource types and their ARNs, see Resources Defined by AWS Billing Conductor in the IAM User Guide. To learn with which actions you can specify the ARN of each resource, see Actions Defined by AWS Billing Conductor.

Condition keys

Administrators can use AWS JSON policies to specify who has access to what. That is, which principal can perform actions on what resources, and under what conditions.

The Condition element (or Condition block) lets you specify conditions in which a statement is in effect. The Condition element is optional. You can create conditional expressions that use condition operators, such as equals or less than, to match the condition in the policy with values in the request.

If you specify multiple Condition elements in a statement, or multiple keys in a single Condition element, AWS evaluates them using a logical AND operation. If you specify multiple values for a single condition key, AWS evaluates the condition using a logical OR operation. All of the conditions must be met before the statement's permissions are granted.

You can also use placeholder variables when you specify conditions. For example, you can grant an IAM user permission to access a resource only if it is tagged with their IAM user name. For more information, see IAM policy elements: variables and tags in the IAM User Guide.

AWS supports global condition keys and service-specific condition keys. To see all AWS global condition keys, see AWS global condition context keys in the IAM User Guide.

Billing Conductor defines its own set of condition keys and also supports using some global condition keys. To see all AWS global condition keys, see AWS Global Condition Context Keys in the IAM User Guide.

All Amazon EC2 actions support the aws:RequestedRegion and ec2:Region condition keys. For more information, see Example: Restricting Access to a Specific Region.

To see a list of Billing Conductor condition keys, see Condition Keys for AWS Billing Conductor in the IAM User Guide. To learn with which actions and resources you can use a condition key, see Actions Defined by AWS Billing Conductor.

Examples

To view examples of Billing Conductor identity-based policies, see AWS Billing Conductor identity-based policy examples.

Billing Conductor resource-based policies

Resource-based policies are JSON policy documents that specify what actions a specified principal can perform on the Billing Conductor resource and under what conditions. Amazon S3 supports resource-based permissions policies for Amazon S3 buckets. Resource-based policies let you grant usage permission to other accounts on a per-resource basis. You can also use a resource-based policy to allow an AWS service to access your Amazon S3 buckets.

To enable cross-account access, you can specify an entire account or IAM entities in another account as the principal in a resource-based policy. Adding a cross-account principal to a resource-based policy is only half of establishing the trust relationship. When the principal and the resource are in different AWS accounts, you must also grant the principal entity permission to access the resource. Grant permission by attaching an identity-based policy to the entity. However, if a resource-based policy grants access to a principal in the same account, no additional identity-based policy is required. For more information, see How IAM Roles Differ from Resource-based Policies in the IAM User Guide.

The Amazon S3 service supports only one type of resource-based policy called a bucket policy, which is attached to a bucket. This policy defines which principal entities (accounts, users, roles, and federated users) can perform actions on the Billing Conductor.

Examples

To view examples of Billing Conductor resource-based policies, see AWS Billing Conductor resource-based policy examples,

Access control lists (ACLs)

Access control lists (ACLs) are lists of grantees that you can attach to resources. They grant accounts permissions to access the resource to which they are attached. You can attach ACLs to an Amazon S3 bucket resource.

With Amazon S3 access control lists (ACLs), you can manage access to bucket resources. Each bucket has an ACL attached to it as a subresource. It defines which AWS accounts, IAM users or groups of users, or IAM roles are granted access and the type of access. When a request is received for a resource, AWS checks the corresponding ACL to verify that the requester has the necessary access permissions.

When you create a bucket resource, Amazon S3 creates a default ACL that grants the resource owner full control over the resource. In the following example bucket ACL, John Doe is listed as the owner of the bucket and is granted full control over that bucket. An ACL can have up to 100 grantees.

<?xml version="1.0" encoding="UTF-8"?>
<AccessControlPolicy xmlns="http://Billing Conductor.amazonaws.com/doc/2006-03-01/">
  <Owner>
    <ID>c1daexampleaaf850ea79cf0430f33d72579fd1611c97f7ded193374c0b163b6</ID>
    <DisplayName>john-doe</DisplayName>
  </Owner>
  <AccessControlList>
    <Grant>
      <Grantee xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
               xsi:type="Canonical User">
        <ID>c1daexampleaaf850ea79cf0430f33d72579fd1611c97f7ded193374c0b163b6</ID>
        <DisplayName>john-doe</DisplayName>
      </Grantee>
      <Permission>FULL_CONTROL</Permission>
    </Grant>
  </AccessControlList>
</AccessControlPolicy> 

The ID field in the ACL is the AWS account canonical user ID. To learn how to view this ID in an account that you own, see Finding an AWS Account Canonical User ID.

Authorization based on Billing Conductor tags

You can attach tags to Billing Conductor resources or pass tags in a request to Billing Conductor. To control access based on tags, you provide tag information in the condition element of a policy using the Billing Conductor:ResourceTag/key-name, aws:RequestTag/key-name, or aws:TagKeys condition keys.

Billing Conductor IAM roles

An IAM role is an entity within your AWS account that has specific permissions.

Using temporary credentials with Billing Conductor

You can use temporary credentials to sign in with federation, assume an IAM role, or to assume a cross-account role. You obtain temporary security credentials by calling AWS STS API operations such as AssumeRole or GetFederationToken.

Billing Conductor supports using temporary credentials.

Service-linked roles

Service-linked roles allow AWS services to access resources in other services to complete an action on your behalf. Service-linked roles appear in your IAM account and are owned by the service. An IAM administrator can view but not edit the permissions for service-linked roles.

Service roles

This feature allows a service to assume a service role on your behalf. This role allows the service to access resources in other services to complete an action on your behalf. Service roles appear in your IAM account and are owned by the account. This means that an IAM administrator can change the permissions for this role. However, doing so might break the functionality of the service.

Billing Conductor supports service roles.

Choosing an IAM role in Billing Conductor

When you create a resource in Billing Conductor, you must choose a role to allow Billing Conductor to access Amazon EC2 on your behalf. If you have previously created a service role or service-linked role, then Billing Conductor provides you with a list of roles to choose from. It's important to choose a role that allows access to start and stop Amazon EC2 instances.