Identity and access management for Amazon Database Migration Service - Amazon Database Migration Service
AudienceAuthenticating with identitiesManaging access using policiesIAM permissions requiredIAM roles for the CLI and API
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Identity and access management for Amazon Database Migration Service

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

Topics

Audience

How you use Amazon Identity and Access Management (IAM) differs, depending on the work that you do in Amazon DMS.

Service user – If you use the Amazon DMS service to do your job, then your administrator provides you with the credentials and permissions that you need. As you use more Amazon DMS features to do your work, you might need additional permissions. Understanding how access is managed can help you request the right permissions from your administrator. If you cannot access a feature in Amazon DMS, see Troubleshooting Amazon Database Migration Service identity and access.

Service administrator – If you're in charge of Amazon DMS resources at your company, you probably have full access to Amazon DMS. It's your job to determine which Amazon DMS features and resources your service users should access. You must then submit requests to your IAM administrator to change the permissions of your service users. Review the information on this page to understand the basic concepts of IAM. To learn more about how your company can use IAM with Amazon DMS, see How Amazon Database Migration Service works with IAM.

IAM administrator – If you're an IAM administrator, you might want to learn details about how you can write policies to manage access to Amazon DMS. To view example Amazon DMS identity-based policies that you can use in IAM, see Amazon Database Migration Service identity-based policy examples.

Authenticating with identities

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

If you access Amazon programmatically, Amazon provides a software development kit (SDK) and a command line interface (CLI) to cryptographically sign your requests by using your credentials. If you don't use Amazon tools, you must sign requests yourself. For more information about using the recommended method to sign requests yourself, see Signing Amazon API requests in the IAM User Guide.

Regardless of the authentication method that you use, you might be required to provide additional security information. For example, Amazon recommends that you use multi-factor authentication (MFA) to increase the security of your account. To learn more, see Using multi-factor authentication (MFA) in Amazon in the IAM User Guide.

Amazon Web Services account root user

When you create an Amazon Web Services account, you begin with one sign-in identity that has complete access to all Amazon Web Services and resources in the account. This identity is called the Amazon Web Services account root user and is accessed by signing in with the email address and password that you used to create the account. We strongly recommend that you don't use the root user for your everyday tasks. Safeguard your root user credentials and use them to perform the tasks that only the root user can perform. For the complete list of tasks that require you to sign in as the root user, see Tasks that require root user credentials in the IAM User Guide.

IAM users and groups

An IAM user is an identity within your Amazon Web Services account that has specific permissions for a single person or application. Where possible, we recommend relying on temporary credentials instead of creating IAM users who have long-term credentials such as passwords and access keys. However, if you have specific use cases that require long-term credentials with IAM users, we recommend that you rotate access keys. For more information, see Rotate access keys regularly for use cases that require long-term credentials in the IAM User Guide.

An IAM group is an identity that specifies a collection of IAM users. You can't sign in as a group. You can use groups to specify permissions for multiple users at a time. Groups make permissions easier to manage for large sets of users. For example, you could have a group named IAMAdmins and give that group permissions to administer IAM resources.

Users are different from roles. A user is uniquely associated with one person or application, but a role is intended to be assumable by anyone who needs it. Users have permanent long-term credentials, but roles provide temporary credentials. To learn more, see When to create an IAM user (instead of a role) in the IAM User Guide.

IAM roles

An IAM role is an identity within your Amazon Web Services account that has specific permissions. It is similar to an IAM user, but is not associated with a specific person. You can temporarily assume an IAM role in the Amazon Web Services Management Console by switching roles. You can assume a role by calling an Amazon CLI or Amazon API operation or by using a custom URL. For more information about methods for using roles, see Using IAM roles in the IAM User Guide.

IAM roles with temporary credentials are useful in the following situations:

  • Federated user access – To assign permissions to a federated identity, you create a role and define permissions for the role. When a federated identity authenticates, the identity is associated with the role and is granted the permissions that are defined by the role. For information about roles for federation, see Creating a role for a third-party Identity Provider in the IAM User Guide.

  • Temporary IAM user permissions – An IAM user or role can assume an IAM role to temporarily take on different permissions for a specific task.

  • Cross-account access – You can use an IAM role to allow someone (a trusted principal) in a different account to access resources in your account. Roles are the primary way to grant cross-account access. However, with some Amazon Web Services, you can attach a policy directly to a resource (instead of using a role as a proxy). To learn the difference between roles and resource-based policies for cross-account access, see How IAM roles differ from resource-based policies in the IAM User Guide.

  • Cross-service access – Some Amazon Web Services use features in other Amazon Web Services. For example, when you make a call in a service, it's common for that service to run applications in Amazon EC2 or store objects in Amazon S3. A service might do this using the calling principal's permissions, using a service role, or using a service-linked role.

    • Forward access sessions (FAS) – When you use an IAM user or role to perform actions in Amazon, you are considered a principal. When you use some services, you might perform an action that then initiates another action in a different service. FAS uses the permissions of the principal calling an Amazon Web Service, combined with the requesting Amazon Web Service to make requests to downstream services. FAS requests are only made when a service receives a request that requires interactions with other Amazon Web Services or resources to complete. In this case, you must have permissions to perform both actions. For policy details when making FAS requests, see Forward access sessions.

    • Service role – A service role is an IAM role that a service assumes to perform actions on your behalf. An IAM administrator can create, modify, and delete a service role from within IAM. For more information, see Creating a role to delegate permissions to an Amazon Web Service in the IAM User Guide.

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

  • Applications running on Amazon EC2 – You can use an IAM role to manage temporary credentials for applications that are running on an EC2 instance and making Amazon CLI or Amazon API requests. This is preferable to storing access keys within the EC2 instance. To assign an Amazon role to an EC2 instance and make it available to all of its applications, you create an instance profile that is attached to the instance. An instance profile contains the role and enables programs that are running on the EC2 instance to get temporary credentials. For more information, see Using an IAM role to grant permissions to applications running on Amazon EC2 instances in the IAM User Guide.

To learn whether to use IAM roles or IAM users, see When to create an IAM role (instead of a user) in the IAM User Guide.

Managing access using policies

You control access in Amazon by creating policies and attaching them to Amazon identities or resources. A policy is an object in Amazon that, when associated with an identity or resource, defines their permissions. Amazon evaluates these policies when a principal (user, root user, or role session) makes a request. Permissions in the policies determine whether the request is allowed or denied. Most policies are stored in Amazon as JSON documents. For more information about the structure and contents of JSON policy documents, see Overview of JSON policies in the IAM User Guide.

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

By default, users and roles have no permissions. To grant users permission to perform actions on the resources that they need, an IAM administrator can create IAM policies. The administrator can then add the IAM policies to roles, and users can assume the roles.

IAM policies define permissions for an action regardless of the method that you use to perform the operation. For example, suppose that you have a policy that allows the iam:GetRole action. A user with that policy can get role information from the Amazon Web Services Management Console, the Amazon CLI, or the Amazon API.

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.

Identity-based policies can be further categorized as inline policies or managed policies. Inline policies are embedded directly into a single user, group, or role. Managed policies are standalone policies that you can attach to multiple users, groups, and roles in your Amazon Web Services account. Managed policies include Amazon managed policies and customer managed policies. To learn how to choose between a managed policy or an inline policy, see Choosing 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 of resource-based policies are 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. For the resource where the policy is attached, the policy defines what actions a specified principal can perform on that resource and under what conditions. You must specify a principal in a resource-based policy. Principals can include accounts, users, roles, federated users, or Amazon Web Services.

Resource-based policies are inline policies that are located in that service. You can't use Amazon 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, Amazon 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

Amazon supports additional, less-common policy types. These policy types can set the maximum permissions granted to you by the more common policy types.

  • Permissions boundaries – A permissions boundary is an advanced feature in which you set the maximum permissions that an identity-based policy can grant to an IAM entity (IAM user or role). You can set a permissions boundary for an entity. The resulting permissions are the intersection of an entity's identity-based policies and its permissions boundaries. Resource-based policies that specify the user or role in the Principal field are not limited by the permissions boundary. An explicit deny in any of these policies overrides the allow. For more information about permissions boundaries, see Permissions boundaries for IAM entities in the IAM User Guide.

  • Service control policies (SCPs) – SCPs are JSON policies that specify the maximum permissions for an organization or organizational unit (OU) in Amazon Organizations. Amazon Organizations is a service for grouping and centrally managing multiple Amazon Web Services accounts that your business owns. If you enable all features in an organization, then you can apply service control policies (SCPs) to any or all of your accounts. The SCP limits permissions for entities in member accounts, including each Amazon Web Services account root user. For more information about Organizations and SCPs, see How SCPs work in the Amazon Organizations User Guide.

  • Session policies – Session policies are advanced policies that you pass as a parameter when you programmatically create a temporary session for a role or federated user. The resulting session's permissions are the intersection of the user or role's identity-based policies and the session policies. Permissions can also come from a resource-based policy. An explicit deny in any of these policies overrides the allow. 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 Amazon 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 Amazon DMS

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

The following policy gives you access to Amazon DMS, and also permissions for certain actions needed from other Amazon services such as Amazon KMS, IAM, Amazon EC2, and Amazon CloudWatch. CloudWatch monitors your Amazon 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 Amazon DMS resources using tagging. For more information about restricting access to Amazon DMS resources using tagging, see Fine-grained access control using resource names and tags.


{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "dms:*",
            "Resource": "arn:aws:dms:region:account:resourcetype/id"
        },
        {
            "Effect": "Allow",
            "Action": [
                "kms:ListAliases", 
                "kms:DescribeKey"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        },
        {
            "Effect": "Allow",
            "Action": [
                "iam:GetRole",
                "iam:PassRole",
                "iam:CreateRole",
                "iam:AttachRolePolicy"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        },
        {
            "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"
        },
        {
            "Effect": "Allow",
            "Action": [
                "cloudwatch:Get*",
                "cloudwatch:List*"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        },
        {
            "Effect": "Allow",
            "Action": [
                "logs:DescribeLogGroups",
                "logs:DescribeLogStreams",
                "logs:FilterLogEvents",
                "logs:GetLogEvents"
            ],
            "Resource": "arn:aws:service:region:account:resourcetype/id"
        }
    ]
}

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 Amazon 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 Amazon 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 Amazon Command Line Interface (Amazon 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 Amazon DMS roles aren't created ahead of time, the Amazon 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 the Amazon CLI and Amazon DMS API.

{
            "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 Amazon 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"
        }

The Amazon DMS console creates several roles that are automatically attached to your Amazon account when you use the Amazon DMS console. If you use the Amazon Command Line Interface (Amazon CLI) or the Amazon DMS API for your migration, you need to add these roles to your account. For more information about adding these roles, see Creating the IAM roles to use with the Amazon CLI and Amazon DMS API.

Creating the IAM roles to use with the Amazon CLI and Amazon DMS API

If you use the Amazon CLI or the Amazon DMS API for your database migration, you must add three IAM roles to your Amazon account before you can use the features of Amazon 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 Amazon 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", 
        "Description": "Provides access to manage VPC settings for AWS managed customer configurations", 
        "CreateDate": "2015-11-18T16:33:19Z", 
        "AttachmentCount": 1, 
        "IsAttachable": true, 
        "PolicyId": "ANPAJHKIGMBQI4AEFFSYO", 
        "DefaultVersionId": "v3", 
        "Path": "/service-role/", 
        "Arn": "arn:aws:iam::aws:policy/service-role/AmazonDMSVPCManagementRole", 
        "UpdateDate": "2016-05-23T16:29:57Z"
    }
}

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 v3

The information returned from the command is as follows.


{
    "PolicyVersion": {
        "CreateDate": "2016-05-23T16:29:57Z", 
        "VersionId": "v3", 
        "Document": {
        "Version": "2012-10-17", 
        "Statement": [
            {
                "Action": [
                    "ec2:CreateNetworkInterface", 
                    "ec2:DescribeAvailabilityZones", 
                    "ec2:DescribeInternetGateways", 
                    "ec2:DescribeSecurityGroups", 
                    "ec2:DescribeSubnets", 
                    "ec2:DescribeVpcs", 
                    "ec2:DeleteNetworkInterface", 
                    "ec2:ModifyNetworkInterfaceAttribute"
                ], 
                "Resource": "arn:aws:service:region:account:resourcetype/id", 
                "Effect": "Allow"
            }
        ]
    }, 
    "IsDefaultVersion": true
    }
}

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

Note

If you use the Amazon DMS console for your database migration, these roles are added to your Amazon account automatically.

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 Amazon CLI or Amazon DMS API

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

    
{
   "Version": "2012-10-17",
   "Statement": [
   {
     "Effect": "Allow",
     "Principal": {
        "Service": "dms.amazonaws.com"
     },
   "Action": "sts:AssumeRole"
   }
 ]
}

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

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

  2. 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 Amazon CLI or Amazon DMS API

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

    
{
   "Version": "2012-10-17",
   "Statement": [
   {
     "Effect": "Allow",
     "Principal": {
        "Service": "dms.amazonaws.com"
     },
   "Action": "sts:AssumeRole"
   }
 ]
}

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

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

  2. 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

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

    
 {
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "1",
      "Effect": "Allow",
      "Principal": {
        "Service": "dms.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    },
    {
      "Sid": "2",
      "Effect": "Allow",
      "Principal": {
        "Service": "redshift.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

  2. Create the role using the Amazon CLI using the following command.

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

  3. 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 Amazon CLI or Amazon DMS API.