AWS Database Migration Service identity-based policy examples

By default, IAM users and roles don't have permission to create or modify AWS DMS resources. They also can't perform tasks using the AWS Management Console, AWS CLI, or AWS API. An IAM administrator must create IAM policies that grant users and roles permission to perform specific API operations on the specified resources they need. The administrator must then attach those policies to the IAM users or groups that require those permissions.

To learn how to create an IAM identity-based policy using these example JSON policy documents, see Creating policies on the JSON tab in the IAM User Guide.

Policy best practices

Identity-based policies determine whether someone can create, access, or delete AWS DMS resources in your account. These actions can incur costs for your AWS account. When you create or edit identity-based policies, follow these guidelines and recommendations:

• Get started with AWS managed policies and move toward least-privilege permissions – To get started granting permissions to your users and workloads, use the AWS managed policies that grant permissions for many common use cases. They are available in your AWS account. We recommend that you reduce permissions further by defining AWS customer managed policies that are specific to your use cases. For more information, see AWS managed policies or AWS managed policies for job functions in the IAM User Guide.

• Apply least-privilege permissions – When you set permissions with IAM policies, grant only the permissions required to perform a task. You do this by defining the actions that can be taken on specific resources under specific conditions, also known as least-privilege permissions. For more information about using IAM to apply permissions, see Policies and permissions in IAM in the IAM User Guide.

• Use conditions in IAM policies to further restrict access – You can add a condition to your policies to limit access to actions and resources. For example, you can write a policy condition to specify that all requests must be sent using SSL. You can also use conditions to grant access to service actions if they are used through a specific AWS service, such as AWS CloudFormation. For more information, see IAM JSON policy elements: Condition in the IAM User Guide.

• Use IAM Access Analyzer to validate your IAM policies to ensure secure and functional permissions – IAM Access Analyzer validates new and existing policies so that the policies adhere to the IAM policy language (JSON) and IAM best practices. IAM Access Analyzer provides more than 100 policy checks and actionable recommendations to help you author secure and functional policies. For more information, see IAM Access Analyzer policy validation in the IAM User Guide.

• Require multi-factor authentication (MFA) – If you have a scenario that requires IAM users or a root user in your AWS account, turn on MFA for additional security. To require MFA when API operations are called, add MFA conditions to your policies. For more information, see Configuring MFA-protected API access in the IAM User Guide.

For more information about best practices in IAM, see Security best practices in IAM in the IAM User Guide.

Using the AWS DMS console

The following policy gives you access to AWS DMS, including the AWS DMS console, and also specifies permissions for certain actions needed from other Amazon services such as Amazon EC2.

{
    "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"
        }
    ]
} 
  
        

A breakdown of these permissions might help you better understand why each one required for using the console is necessary.

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 a 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 has the ability to create the role. If all roles are configured ahead of time, all that is required in iam:GetRole and iam:PassRole. For more information about roles, see Creating the IAM roles to use with the AWS CLI and AWS 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 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"
        }

The AWS DMS console creates several roles that are automatically attached to your AWS account when you use the AWS DMS console. If you use the AWS Command Line Interface (AWS CLI) or the AWS 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 AWS CLI and AWS DMS API.

For more information on the requirements for using this policy to access AWS DMS, see IAM permissions needed to use AWS DMS.

Allow users to view their own permissions

This example shows how you might create a policy that allows IAM users to view the inline and managed policies that are attached to their user identity. This policy includes permissions to complete this action on the console or programmatically using the AWS CLI or AWS API.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ViewOwnUserInfo",
            "Effect": "Allow",
            "Action": [
                "iam:GetUserPolicy",
                "iam:ListGroupsForUser",
                "iam:ListAttachedUserPolicies",
                "iam:ListUserPolicies",
                "iam:GetUser"
            ],
            "Resource": ["arn:aws:iam::*:user/${aws:username}"]
        },
        {
            "Sid": "NavigateInConsole",
            "Effect": "Allow",
            "Action": [
                "iam:GetGroupPolicy",
                "iam:GetPolicyVersion",
                "iam:GetPolicy",
                "iam:ListAttachedGroupPolicies",
                "iam:ListGroupPolicies",
                "iam:ListPolicyVersions",
                "iam:ListPolicies",
                "iam:ListUsers"
            ],
            "Resource": "*"
        }
    ]
}

Accessing one Amazon S3 bucket

AWS DMS uses Amazon S3 buckets as intermediate storage for database migration. Typically, AWS DMS manages default S3 buckets for this purpose. However, in certain cases, especially when you use the AWS CLI or the AWS DMS API, AWS DMS enables you to specify your own S3 bucket instead. For example, you can specify your own S3 bucket for migrating data to an Amazon Redshift target endpoint. In this case, you need to create a role with permissions based on the AWS-managed AmazonDMSRedshiftS3Role policy.

The following example shows a version of the AmazonDMSRedshiftS3Role policy. It allows AWS DMS to grant an IAM user in your AWS account access to one of your Amazon S3 buckets. It also allows the user to add, update, and delete objects.

In addition to granting the s3:PutObject, s3:GetObject, and s3:DeleteObject permissions to the user, the policy also grants the s3:ListAllMyBuckets, s3:GetBucketLocation, and s3:ListBucket permissions. These are the additional permissions required by the console. Other permissions allow AWS DMS to manage the bucket life cycle. Also, the s3:GetObjectAcl action is required to be able to copy objects.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:CreateBucket",
                "s3:ListBucket",
                "s3:DeleteBucket",
                "s3:GetBucketLocation",
                "s3:GetObject",
                "s3:PutObject",
                "s3:DeleteObject",
                "s3:GetObjectVersion",
                "s3:GetBucketPolicy",
                "s3:PutBucketPolicy",
                "s3:GetBucketAcl",
                "s3:PutBucketVersioning",
                "s3:GetBucketVersioning",
                "s3:PutLifecycleConfiguration",
                "s3:GetLifecycleConfiguration",
                "s3:DeleteBucketPolicy"
            ],
            "Resource": "arn:aws:s3:::dms-*"
        }
    ]
}

For more information on creating a role based on this policy, see Amazon S3 bucket settings.

Accessing AWS DMS resources based on tags

You can use conditions in your identity-based policy to control access to AWS DMS resources based on tags. This example shows how you might create a policy that allows access to all AWS DMS endpoints. However, permission is granted only if the endpoint database tag Owner has the value of that user's user name.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "dms:*",
            "Resource": "arn:aws:dms:*:*:endpoint/*",
            "Condition": {
                "StringEquals": {"dms:endpoint-tag/Owner": "${aws:username}"}
            }
        }
    ]
}

You can attach this policy to the IAM users in your account. If a user named richard-roe attempts to access an AWS DMS endpoint, the endpoint database must be tagged Owner=richard-roe or owner=richard-roe. Otherwise, this user is denied access. The condition tag key Owner matches both Owner and owner because condition key names are not case-sensitive. For more information, see IAM JSON policy elements: Condition in the IAM User Guide.