How Application Auto Scaling works with IAM

Before you use IAM to manage access to Application Auto Scaling, learn what IAM features are available to use with Application Auto Scaling.

To get a high-level view of how Application Auto Scaling and other AWS services work with most IAM features, see AWS services that work with IAM in the IAM User Guide.

Application Auto Scaling identity-based policies

Identity-based policies are JSON permissions policy documents that you can attach to an identity, such as an IAM user, group of users, or role. These policies control what actions users and roles can perform, on which resources, and under what conditions. To learn how to create an identity-based policy, see Creating IAM policies in the IAM User Guide.

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. You can't specify the principal in an identity-based policy because it applies to the user or role to which it is attached. To learn about all of the elements that you can use in a JSON policy, see IAM JSON policy elements reference in the IAM User Guide.

Identity-based policy examples for Application Auto Scaling

To view examples of Application Auto Scaling identity-based policies, see Application Auto Scaling identity-based policy examples.

Actions

In an IAM policy statement, you can specify any API action from any service that supports IAM. For Application Auto Scaling, use the following prefix with the name of the API action: application-autoscaling:. For example: application-autoscaling:RegisterScalableTarget, application-autoscaling:PutScalingPolicy, and application-autoscaling:DeregisterScalableTarget.

To specify multiple actions in a single statement, separate them with commas as shown in the following example.

"Action": [
      "application-autoscaling:DescribeScalingPolicies",
      "application-autoscaling:DescribeScalingActivities"

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

"Action": "application-autoscaling:Describe*"

For a list of Application Auto Scaling actions, see Actions defined by AWS Application Auto Scaling in the Service Authorization Reference.

Resources

In an IAM policy statement, the Resource element specifies the object or objects that the statement covers. For Application Auto Scaling, each IAM policy statement applies to the scalable targets that you specify using their Amazon Resource Names (ARNs).

The ARN resource format for scalable targets:

arn:aws:application-autoscaling:region:account-id:scalable-target/unique-identifier

For example, you can indicate a specific scalable target in your statement using its ARN as follows. The unique ID (1234abcd56ab78cd901ef1234567890ab123) is a value assigned by Application Auto Scaling to the scalable target.

"Resource": "arn:aws:application-autoscaling:us-east-1:123456789012:scalable-target/1234abcd56ab78cd901ef1234567890ab123"

You can specify all instances that belong to a specific account by replacing the unique identifier with a wildcard (*) as follows.

"Resource": "arn:aws:application-autoscaling:us-east-1:123456789012:scalable-target/*"

To specify all resources, or if a specific API action does not support ARNs, use a wildcard (*) as the Resource element as follows.

"Resource": "*"

For more information, see Resource types defined by AWS Application Auto Scaling in the Service Authorization Reference.

Condition keys

You can specify conditions in the IAM policies that control access to Application Auto Scaling resources. The policy statement is effective only when the conditions are true.

Application Auto Scaling supports the following service-defined condition keys that you can use in identity-based policies to determine who can perform Application Auto Scaling API actions.

To learn which Application Auto Scaling API actions you can use a condition key with, see Actions defined by AWS Application Auto Scaling in the Service Authorization Reference. For more information about using Application Auto Scaling condition keys, see Condition keys for AWS Application Auto Scaling.

To view the global condition keys that are available to all services, see AWS global condition context keys in the IAM User Guide.

Resource-based policies

Other AWS services, such as Amazon Simple Storage Service, support resource-based permissions policies. For example, you can attach a permissions policy to an S3 bucket to manage access permissions to that bucket.

Application Auto Scaling does not support resource-based policies.

Access Control Lists (ACLs)

Application Auto Scaling does not support Access Control Lists (ACLs).

ABAC with Application Auto Scaling

Attribute-based access control (ABAC) is an authorization strategy that defines permissions based on attributes. In AWS, these attributes are called tags. You can attach tags to IAM entities (users or roles) and to many AWS resources. Tagging entities and resources is the first step of ABAC. Then you design ABAC policies to allow operations when the principal's tag matches the tag on the resource that they are trying to access.

ABAC is helpful in environments that are growing rapidly and helps with situations where policy management becomes cumbersome.

To control access based on tags, you provide tag information in the condition element of a policy using the aws:ResourceTag/key-name, aws:RequestTag/key-name, or aws:TagKeys condition keys.

ABAC is possible for resources that support tags, but not everything supports tags. Scheduled actions and scaling policies don't support tags, but scalable targets support tags. For more information, see Tagging support for Application Auto Scaling.

For more information about ABAC, see What is ABAC? in the IAM User Guide. To view a tutorial with steps for setting up ABAC, see Use attribute-based access control (ABAC) in the IAM User Guide.

Using temporary credentials with Application Auto Scaling

Some AWS services don't work when you sign in using temporary credentials. For additional information, including which AWS services work with temporary credentials, see AWS services that work with IAM in the IAM User Guide.

You are using temporary credentials if you sign in to the AWS Management Console using any method except a user name and password. For example, when you access AWS using your company's single sign-on (SSO) link, that process automatically creates temporary credentials. You also automatically create temporary credentials when you sign in to the console as a user and then switch roles. For more information about switching roles, see Switching to a role (console) in the IAM User Guide.

You can manually create temporary credentials using the AWS CLI or AWS API. You can then use those temporary credentials to access AWS. AWS recommends that you dynamically generate temporary credentials instead of using long-term access keys. For more information, see Temporary security credentials in IAM.

Service roles

If your Amazon EMR cluster uses automatic scaling, this feature allows Application Auto Scaling to assume a service role on your behalf. Similar to a service-linked role, a service 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.

Application Auto Scaling supports service roles only for Amazon EMR. For documentation for the EMR service role, see Using automatic scaling with a custom policy for instance groups in the Amazon EMR Management Guide.

Service-linked roles

A service-linked role is a type of service role that is linked to an AWS service. The service can assume the role to perform an action on your behalf. Service-linked roles appear in your AWS account and are owned by the service. An IAM administrator can view, but not edit the permissions for service-linked roles.

For information about Application Auto Scaling service-linked roles, see Service-linked roles for Application Auto Scaling.