DMS - Support for Managed Identity for Azure SQL Managed Instance migration
Azure Database Migration Service (DMS) has introduced a new feature that supports the use of Managed Identity for migrating to Azure SQL Managed Instance. This enhancement simplifies the migration process and ensures secure and seamless integration with Azure Database Migration services. In this blog post, we will dive into the prerequisites, permissions or role(s) required, and how to use this associated Managed identity for migrating to Azure SQL Managed Instance. Currently, this feature is supported through Azure Portal, PowerShell, and Az cmdlets. Prerequisites Before you begin the migration to Azure SQL Managed Instance using Managed identity, ensure that following prerequisites are in place: 1. The Target Azure SQL Managed Instance's associated Managed Identity: Azure Database Migration Service only supports Managed Identity that is associated with the target Azure SQL Managed Instance. How to identify the associated Managed Identity? Once you start the migration to Azure SQL Managed Instance using Azure Database Migration Service and on second page, select the target Azure SQL Managed instance, its associated Managed Identity will be displayed if "Use Managed Identity" is selected (default), as highlighted below. Alternatively, you can follow these steps: a) Go to the target Azure SQL Managed Instance's home page. b) On the left menu, under Security > Identity: If User-assigned Managed Identity is present, the associated Managed Identity will be same as selected under the Primary Identity. If there is no User-assigned Managed Identity and only System-assigned Managed Identity is enabled, the associated Managed Identity will be System-assigned Managed Identity and have the same name as the Azure SQL Managed Instance's name. For example, for ABCSQLMI - Azure SQL Managed Instance the System-assigned Managed Identity will be "ABCSQLMI". 2) Permissions: Assign the "Storage Blob Data Reader" role on the storage account to the target instance's associated Managed Identity. Steps to Assign Permissions In the Azure portal, go to the storage account that will be used in migration for keeping the backup files. On the left menu under Access Control (IAM), click on "+Add" > Add role assignment Select or search for builtin role "Storage Blob Data Reader", click Next. Assing this role access to Managed Identity by selecting the associated Managed Identity identified in the previous step as the member. Note: When migrating to Azure SQL Managed Instance or Azure SQL Virtual Machine via Azure portal make sure the signed in user has Storage Blob Data Reader access on the Blob container that contains the backup files. This permission is needed to list folders and files in the blob container during migration setup via Azure portal only. How to use associated Managed identity for migration? Upon initiating the migration to Azure SQL Managed Instance using Azure Database Migration Service, navigate to the second page and select the target Azure SQL Managed Instance. If the "Use Managed Identity" option is selected (default), the associated Managed Identity will be displayed and used for the migration (as shown in the first image above). Once Managed identity is used for the migration, DMS will utilize this Managed identity for reading the backup files on the Azure blob storage and thus removing the need for SAS keys. Limitations: Azure Database Migration Service supports Managed Identity that is associated with the target Azure SQL Managed Instance only. It can be either User assigned, or System assigned Managed identity. Currently, this feature is supported through Azure Portal only. Ensure that the storage account has the "Allow storage account key access" enabled. Benefits of using Managed Identity: Using Managed Identity for Azure SQL Managed Instance migrations offers several security benefits: Enhanced Security: Managed identities eliminate the need to use SAS key, reducing the risk of SAS key token exposure. Simplified Management: As associated Managed Identity of the target Azure SQL MI is used, it allows for seamless integration with Azure Database Migration services, making it easier to manage access permissions and roles. Improved Efficiency: The streamlined authentication process speeds up migrations and reduces the complexity of managing SAS keys. Improved Compliance: By using Managed Identity, user can ensure that they adhere to security best practices and compliance requirements, as it is managed securely by Azure. All the above benefits make Managed Identity better than SAS key token. Learn more. Conclusion The new feature supporting Managed Identity in Azure Database Migration Service for Azure SQL Managed Instance migrations offers a secure and efficient way to manage permissions during the migration process. By following the steps outlined above and leveraging the security benefits of Managed Identity, you can ensure a smooth and secure migration to Azure SQL Managed Instance.
