Audience Authenticating with identities Managing access using policies IAM permissions required IAM roles for the AWS DMS console, CLI and API

Identity and access management for AWS Database Migration Service

AWS Identity and Access Management (IAM) is an AWS service that helps an administrator securely control access to AWS resources. IAM administrators control who can be authenticated (signed in) and authorized (have permissions) to use AWS DMS resources. IAM is an AWS service that you can use with no additional charge.

Topics

Audience

How you use AWS Identity and Access Management (IAM) differs based on your role:

Service user - request permissions from your administrator if you cannot access features (see Troubleshooting AWS Database Migration Service identity and access)
Service administrator - determine user access and submit permission requests (see How AWS Database Migration Service works with IAM)
IAM administrator - write policies to manage access (see AWS Database Migration Service identity-based policy examples)

Authenticating with identities

Authentication is how you sign in to AWS using your identity credentials. You must be authenticated as the AWS account root user, an IAM user, or by assuming an IAM role.

You can sign in as a federated identity using credentials from an identity source like AWS IAM Identity Center (IAM Identity Center), single sign-on authentication, or Google/Facebook credentials. For more information about signing in, see How to sign in to your AWS account in the AWS Sign-In User Guide.

For programmatic access, AWS provides an SDK and CLI to cryptographically sign requests. For more information, see AWS Signature Version 4 for API requests in the IAM User Guide.

AWS account root user

When you create an AWS account, you begin with one sign-in identity called the AWS account root user that has complete access to all AWS services and resources. We strongly recommend that you don't use the root user for everyday tasks. For tasks that require root user credentials, see Tasks that require root user credentials in the IAM User Guide.

IAM users and groups

An IAM user is an identity with specific permissions for a single person or application. We recommend using temporary credentials instead of IAM users with long-term credentials. For more information, see Require human users to use federation with an identity provider to access AWS using temporary credentials in the IAM User Guide.

An IAM group specifies a collection of IAM users and makes permissions easier to manage for large sets of users. For more information, see Use cases for IAM users in the IAM User Guide.

IAM roles

An IAM role is an identity with specific permissions that provides temporary credentials. You can assume a role by switching from a user to an IAM role (console) or by calling an AWS CLI or AWS API operation. For more information, see Methods to assume a role in the IAM User Guide.

IAM roles are useful for federated user access, temporary IAM user permissions, cross-account access, cross-service access, and applications running on Amazon EC2. For more information, see Cross account resource access in IAM in the IAM User Guide.

Managing access using policies

You control access in AWS by creating policies and attaching them to AWS identities or resources. A policy defines permissions when associated with an identity or resource. AWS evaluates these policies when a principal makes a request. Most policies are stored in AWS as JSON documents. For more information about JSON policy documents, see Overview of JSON policies in the IAM User Guide.

Using policies, administrators specify who has access to what by defining which principal can perform actions on what resources, and under what conditions.

By default, users and roles have no permissions. An IAM administrator creates IAM policies and adds them to roles, which users can then assume. IAM policies define permissions regardless of the method used to perform the operation.

Identity-based policies

Identity-based policies are JSON permissions policy documents that you attach to an identity (user, group, or role). These policies control what actions identities can perform, on which resources, and under what conditions. To learn how to create an identity-based policy, see Define custom IAM permissions with customer managed policies in the IAM User Guide.

Identity-based policies can be inline policies (embedded directly into a single identity) or managed policies (standalone policies attached to multiple identities). To learn how to choose between managed and inline policies, see Choose between managed policies and inline policies in the IAM User Guide.

Resource-based policies

Resource-based policies are JSON policy documents that you attach to a resource. Examples include IAM role trust policies and Amazon S3 bucket policies. In services that support resource-based policies, service administrators can use them to control access to a specific resource. You must specify a principal in a resource-based policy.

Resource-based policies are inline policies that are located in that service. You can't use AWS managed policies from IAM in a resource-based policy.

Access control lists (ACLs)

Access control lists (ACLs) control which principals (account members, users, or roles) have permissions to access a resource. ACLs are similar to resource-based policies, although they do not use the JSON policy document format.

Amazon S3, AWS WAF, and Amazon VPC are examples of services that support ACLs. To learn more about ACLs, see Access control list (ACL) overview in the Amazon Simple Storage Service Developer Guide.

Other policy types

AWS supports additional policy types that can set the maximum permissions granted by more common policy types:

Permissions boundaries – Set the maximum permissions that an identity-based policy can grant to an IAM entity. For more information, see Permissions boundaries for IAM entities in the IAM User Guide.
Service control policies (SCPs) – Specify the maximum permissions for an organization or organizational unit in AWS Organizations. For more information, see Service control policies in the AWS Organizations User Guide.
Resource control policies (RCPs) – Set the maximum available permissions for resources in your accounts. For more information, see Resource control policies (RCPs) in the AWS Organizations User Guide.
Session policies – Advanced policies passed as a parameter when creating a temporary session for a role or federated user. For more information, see Session policies in the IAM User Guide.

Multiple policy types

When multiple types of policies apply to a request, the resulting permissions are more complicated to understand. To learn how AWS determines whether to allow a request when multiple policy types are involved, see Policy evaluation logic in the IAM User Guide.

IAM permissions needed to use AWS DMS

You use certain IAM permissions and IAM roles to use AWS DMS. If you are signed in as an IAM user and want to use AWS DMS, your account administrator must attach the policy discussed in this section to the IAM user, group, or role that you use to run AWS DMS. For more information about IAM permissions, see the IAM User Guide.

The following policy gives you access to AWS DMS, and also permissions for certain actions needed from other Amazon services such as AWS KMS, IAM, Amazon EC2, and Amazon CloudWatch. CloudWatch monitors your AWS DMS migration in real time and collects and tracks metrics that indicate the progress of your migration. You can use CloudWatch Logs to debug problems with a task.

Note

You can further restrict access to AWS DMS resources using tagging. For more information about restricting access to AWS DMS resources using tagging, see Fine-grained access control using resource names and tags.

The breakdown of these following permissions might help you better understand why each one is necessary.

The following section is required to allow the user to call AWS DMS API operations.


{
            "Effect": "Allow",
            "Action": "dms:*",
            "Resource": "arn:aws:dms:region:account:resourcetype/id"
}

The following section is required to allow the user to list their available AWS KMS keys and alias for display in the console. This entry is not required if you know the Amazon Resource Name (ARN) for the KMS key and you are using only the AWS Command Line Interface (AWS CLI).


{
            "Effect": "Allow",
            "Action": [
                "kms:ListAliases", 
                "kms:DescribeKey"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        }

The following section is required for certain endpoint types that require an IAM role ARN to be passed in with the endpoint. In addition, if the required AWS DMS roles aren't created ahead of time, the AWS DMS console can create the role. If all roles are configured ahead of time, all that is required is iam:GetRole and iam:PassRole. For more information about roles, see Creating the IAM roles to use with AWS DMS.


{
            "Effect": "Allow",
            "Action": [
                "iam:GetRole",
                "iam:PassRole",
                "iam:CreateRole",
                "iam:AttachRolePolicy"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        }

The following section is required because AWS DMS needs to create the Amazon EC2 instance and configure the network for the replication instance that is created. These resources exist in the customer's account, so the ability to perform these actions on behalf of the customer is required.


{
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeVpcs",
                "ec2:DescribeInternetGateways",
                "ec2:DescribeAvailabilityZones",
                "ec2:DescribeSubnets",
                "ec2:DescribeSecurityGroups",
                "ec2:ModifyNetworkInterfaceAttribute",
                "ec2:CreateNetworkInterface",
                "ec2:DeleteNetworkInterface"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        }

The following section is required to allow the user to be able to view replication instance metrics.


{
            "Effect": "Allow",
            "Action": [
                "cloudwatch:Get*",
                "cloudwatch:List*"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        }

This section is required to allow the user to view replication logs.


{
            "Effect": "Allow",
            "Action": [
                "logs:DescribeLogGroups",
                "logs:DescribeLogStreams",
                "logs:FilterLogEvents",
                "logs:GetLogEvents"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        }

If you use the AWS DMS console, the AWS Command Line Interface (AWS CLI) or the AWS DMS API for your migration, you need to add several roles to your account. For more information about adding these roles, see Creating the IAM roles to use with AWS DMS.

Creating the IAM roles to use with AWS DMS

If you use the AWS DMS console, the AWS CLI or the AWS DMS API for your database migration, you must add three 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.

Updates to managed policies are automatic. If you are using a custom policy with the IAM roles, be sure to periodically check for updates to the managed policy in this documentation. You can view the details of the managed policy by using a combination of the get-policy and get-policy-version commands.

For example, the following get-policy command retrieves information about the specified IAM role.



aws iam get-policy --policy-arn arn:aws:iam::aws:policy/service-role/AmazonDMSVPCManagementRole

The information returned from the command is as follows.



{
    "Policy": {
        "PolicyName": "AmazonDMSVPCManagementRole",
        "PolicyId": "ANPAJHKIGMBQI4AEFFSYO",
        "Arn": "arn:aws:iam::aws:policy/service-role/AmazonDMSVPCManagementRole",
        "Path": "/service-role/",
        "DefaultVersionId": "v4",
        "AttachmentCount": 1,
        "PermissionsBoundaryUsageCount": 0,
        "IsAttachable": true,
        "Description": "Provides access to manage VPC settings for AWS managed customer configurations",
        "CreateDate": "2015-11-18T16:33:19+00:00",
        "UpdateDate": "2024-07-25T15:19:01+00:00",
        "Tags": []
    }
}

The following get-policy-version command retrieves IAM policy information.



aws iam get-policy-version --policy-arn arn:aws:iam::aws:policy/service-role/AmazonDMSVPCManagementRole --version-id v4

The information returned from the command is as follows.



{
    "PolicyVersion": {
        "Document": {
            "Version": "2012-10-17",		 	 	 
            "Statement": [
                {
                    "Sid": "Statement1",
                    "Effect": "Allow",
                    "Action": [
                        "ec2:CreateNetworkInterface",
                        "ec2:DeleteNetworkInterface",
                        "ec2:DescribeAvailabilityZones",
                        "ec2:DescribeDhcpOptions",
                        "ec2:DescribeInternetGateways",
                        "ec2:DescribeNetworkInterfaces",
                        "ec2:DescribeSecurityGroups",
                        "ec2:DescribeSubnets",
                        "ec2:DescribeVpcs",
                        "ec2:ModifyNetworkInterfaceAttribute"
                    ],
                    "Resource": "*"
                }
            ]
        },
        "VersionId": "v4",
        "IsDefaultVersion": true,
        "CreateDate": "2024-07-25T15:19:01+00:00"
    }
}

You can use the same commands to get information about AmazonDMSCloudWatchLogsRole and the AmazonDMSRedshiftS3Role managed policy.

The following procedures create the dms-vpc-role, dms-cloudwatch-logs-role, and dms-access-for-endpoint IAM roles.

To create the dms-vpc-role IAM role for use with the AWS CLI or AWS DMS API

Create a JSON file with the following IAM policy. Name the JSON file dmsAssumeRolePolicyDocument.json.

Create the role using the AWS CLI using the following command.



aws iam create-role --role-name dms-vpc-role --assume-role-policy-document file://dmsAssumeRolePolicyDocument.json

Attach the AmazonDMSVPCManagementRole policy to dms-vpc-role using the following command.



aws iam attach-role-policy --role-name dms-vpc-role --policy-arn arn:aws:iam::aws:policy/service-role/AmazonDMSVPCManagementRole

To create the dms-cloudwatch-logs-role IAM role for use with the AWS CLI or AWS DMS API

Create a JSON file with the following IAM policy. Name the JSON file dmsAssumeRolePolicyDocument2.json.

Create the role using the AWS CLI using the following command.



aws iam create-role --role-name dms-cloudwatch-logs-role --assume-role-policy-document file://dmsAssumeRolePolicyDocument2.json

Attach the AmazonDMSCloudWatchLogsRole policy to dms-cloudwatch-logs-role using the following command.



aws iam attach-role-policy --role-name dms-cloudwatch-logs-role --policy-arn arn:aws:iam::aws:policy/service-role/AmazonDMSCloudWatchLogsRole

If you use Amazon Redshift as your target database, you must create the IAM role dms-access-for-endpoint to provide access to Amazon S3.

To create the dms-access-for-endpoint IAM role for use with Amazon Redshift as a target database

Create a JSON file with the following IAM policy. Name the JSON file dmsAssumeRolePolicyDocument3.json.

Create the role using the AWS CLI using the following command.



  aws iam create-role --role-name dms-access-for-endpoint --assume-role-policy-document file://dmsAssumeRolePolicyDocument3.json

Attach the AmazonDMSRedshiftS3Role policy to dms-access-for-endpoint role using the following command.



aws iam attach-role-policy --role-name dms-access-for-endpoint \
    --policy-arn arn:aws:iam::aws:policy/service-role/AmazonDMSRedshiftS3Role

You should now have the IAM policies in place to use the AWS CLI or AWS DMS API.

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