How AWS Database Migration Service works with IAM

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

AWS DMS identity-based policies

With IAM identity-based policies, you can specify allowed or denied actions and resources, and also the conditions under which actions are allowed or denied. AWS DMS 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 AWS DMS use the following prefix before the action: dms:. For example, to grant someone permission to create a replication task with the AWS DMS CreateReplicationTask API operation, you include the dms:CreateReplicationTask action in their policy. Policy statements must include either an Action or NotAction element. AWS DMS 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": [
      "dms:action1",
      "dms: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": "dms:Describe*"

To see a list of AWS DMS actions, see Actions Defined by AWS Database Migration Service 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": "*"

AWS DMS works with the following resources:

The resource or resources that AWS DMS requires depends on the action or actions that you invoke. You need a policy that permits these actions on the associated resource or resources specified by the resource ARNs.

For example, an AWS DMS endpoint resource has the following ARN:

arn:${Partition}:dms:${Region}:${Account}:endpoint/${InstanceId}

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

For example, to specify the 1A2B3C4D5E6F7G8H9I0J1K2L3M endpoint instance for the us-east-2 region in your statement, use the following ARN.

"Resource": "arn:aws:dms:us-east-2:987654321098:endpoint/1A2B3C4D5E6F7G8H9I0J1K2L3M"

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

"Resource": "arn:aws:dms:us-east-2:987654321098:endpoint/*"

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

"Resource": "*"

Some AWS DMS API actions involve multiple resources. For example, StartReplicationTask starts and connects a replication task to two database endpoint resources, a source and a target, so an IAM user must have permissions to read the source endpoint and to write to the target endpoint. To specify multiple resources in a single statement, separate the ARNs with commas.

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

For more information on controlling access to AWS DMS resources using policies, see Using resource names to control access. To see a list of AWS DMS resource types and their ARNs, see Resources Defined by AWS Database Migration Service in the IAM User Guide. To learn with which actions you can specify the ARN of each resource, see Actions Defined by AWS Database Migration Service.

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.

AWS DMS 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.

AWS DMS defines a set of standard tags that you can use in its condition keys and also allows you defined your own custom tags. For more information, see Using tags to control access.

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

Examples

To view examples of AWS DMS identity-based policies, see AWS Database Migration Service identity-based policy examples.

AWS DMS resource-based policies

Resource-based policies are JSON policy documents that specify what actions a specified principal can perform on a given AWS DMS resource and under what conditions. AWS DMS supports resource-based permissions policies for AWS KMS encryption keys that you create to encrypt data migrated to supported target endpoints. The supported target endpoints include Amazon Redshift and Amazon S3. By using resource-based policies, you can grant the permission for using these encryption keys to other accounts for each target endpoint.

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 AWS DMS service supports only one type of resource-based policy called a key policy, which is attached to an AWS KMS encryption key. This policy defines which principal entities (accounts, users, roles, and federated users) can encrypt migrated data on the supported target endpoint.

To learn how to attach a resource-based policy to an encryption key that you create for the supported target endpoints, see Creating and using AWS KMS keys to encrypt Amazon Redshift target data and Creating AWS KMS keys to encrypt Amazon S3 target objects.

Examples

For examples of AWS DMS resource-based policies, see Resource-based policy examples for AWS KMS.

Authorization based on AWS DMS tags

You can attach tags to AWS DMS resources or pass tags in a request to AWS DMS. To control access based on tags, you provide tag information in the condition element of a policy using the dms:ResourceTag/key-name, aws:RequestTag/key-name, or aws:TagKeys condition key. AWS DMS defines a set of standard tags that you can use in its condition keys and also enables you to define your own custom tags. For more information, see Using tags to control access.

For an example identity-based policy that limits access to a resource based on tags, see Accessing AWS DMS resources based on tags.

IAM roles for AWS DMS

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

Using temporary credentials with AWS DMS

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

AWS DMS 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.

For details about creating or managing AWS DMS service-linked roles, see Using 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.

AWS DMS supports two types of service roles that you must create to use certain source or target endpoints:

Choosing an IAM role in AWS DMS

If you use the AWS DMS console, the AWS CLI or the AWS DMS API for your database migration, you must add certain IAM roles to your AWS account before you can use the features of AWS DMS. Two of these are dms-vpc-role and dms-cloudwatch-logs-role. If you use Amazon Redshift as a target database, you must also add the IAM role dms-access-for-endpoint to your AWS account. For more information, see Creating the IAM roles to use with AWS DMS.

Identity and access management for DMS Fleet Advisor

With IAM identity-based policies, you can specify allowed or denied actions and resources, and also the conditions under which actions are allowed or denied. DMS Fleet Advisor 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.

DMS Fleet Advisor uses IAM roles to access Amazon Simple Storage Service. An IAM role is an entity within your AWS account that has specific permissions. For more information, see Create IAM resources.