Use Managed Identity with Cosmos DB

Question

I'd like to use managed identity when connecting to cosmos db table api from an azure function.

Uri tableEndpoint = new Uri("https://mycosmos.table.cosmos.azure.com:443/");
var tableServiceClient = new TableServiceClient(tableEndpoint, new DefaultAzureCredential());

var tableClient = tableServiceClient.GetTableClient(tableName);

This causes the following error:

Authorization header doesn't confirm to the required format

I've read that cosmos db table api does not yet support managed identity but that was over 2 years ago - I'm hoping that it is now possible?

Answer 1

As per November 2023, this is still not supported (see documentation):

Which Azure Cosmos DB APIs support role-based access control?

The API for NoSQL is supported. Support for the API for MongoDB is in preview.

Azure Storage Table do support managed identity and could be an alternative:

• Authorize access to tables using Microsoft Entra ID.
  you would need to grant Storage Table Data Contributor or Storage Table Data Reader role to the managed identity.

And here is a good article to check between storage and cosmos table:

• Develop with Azure Cosmos DB for Table and Azure Table Storage