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Integrate the Azure Cosmos DB for Table with Service Connector

This article shows supported authentication methods and clients, and provides sample code for connecting Azure Cosmos DB for Table to cloud services using Service Connector. You can also connect using other programming languages without Service Connector. The article includes default environment variable names and values you receive when creating a service connection.

Supported compute services

Service Connector can be used to connect the following compute services to Azure Cosmos DB for Table:

  • Azure App Service
  • Azure Functions
  • Azure Kubernetes Service (AKS)
  • Azure Spring Apps

Supported authentication types and client types

The table below shows which combinations of client types and authentication methods are supported for connecting your compute service to Azure Cosmos DB for Table using Service Connector. A “Yes” indicates that the combination is supported, while a “No” indicates that it is not supported.

Client type System-assigned managed identity User-assigned managed identity Secret / connection string Service principal
.NET Yes Yes Yes Yes
Java Yes Yes Yes Yes
Node.js Yes Yes Yes Yes
Python Yes Yes Yes Yes
Go Yes Yes Yes Yes
None Yes Yes Yes Yes

This table indicates that all combinations of client types and authentication methods in the table are supported. All client types can use any of the authentication methods to connect to Azure Cosmos DB for Table using Service Connector.

Note

Cosmos DB does not natively support authentication via managed identity. Therefore, Service Connector uses the managed identity to retrieve the connection string, and the connection is subsequently established using that connection string.

Default environment variable names or application properties and sample code

Refer to the connection details below to connect your compute services to Azure Cosmos DB for Table. Replace placeholder text such as <account-name>, <table-name>, and <account-key> with your actual values. For naming conventions, see Service Connector internals.

System-assigned managed identity

Default environment variable name Description Example value
AZURE_COSMOS_LISTCONNECTIONSTRINGURL The URL to get the connection string https://management.azure.com/subscriptions/<subscription-ID>/resourceGroups/<resource-group-name>/providers/Microsoft.DocumentDB/databaseAccounts/<table-name>/listConnectionStrings?api-version=2021-04-15
AZURE_COSMOS_SCOPE Your managed identity scope https://management.azure.com/.default
AZURE_COSMOS_RESOURCEENDPOINT Your resource endpoint https://<table-name>.documents.azure.com:443/

Sample code

To connect using a system-assigned managed identity:

  1. Install dependencies.
    dotnet add package Azure.Data.Tables
    dotnet add package Azure.Identity
    
  2. Get an access token for the managed identity or service principal using Azure.Identity. Use the access token and AZURE_COSMOS_LISTCONNECTIONSTRINGURL to get the connection string and connect to Azure Cosmos DB for Table. In the code below, uncomment the section for your authentication type:
    using System;
    using System.Security.Authentication;
    using System.Net.Security;
    using System.Net.Http;
    using System.Security.Authentication;
    using System.Threading.Tasks;
    using Azure.Data.Tables;
    using Azure.Identity;
    
    var endpoint = Environment.GetEnvironmentVariable("AZURE_COSMOS_RESOURCEENDPOINT");
    var listConnectionStringUrl = Environment.GetEnvironmentVariable("AZURE_COSMOS_LISTCONNECTIONSTRINGURL");
    var scope = Environment.GetEnvironmentVariable("AZURE_COSMOS_SCOPE");
    
    // Uncomment the following lines corresponding to the authentication type you want to use.
    // For system-assigned identity.
    // var tokenProvider = new DefaultAzureCredential();
    
    // For user-assigned identity.
    // var tokenProvider = new DefaultAzureCredential(
    //     new DefaultAzureCredentialOptions
    //     {
    //         ManagedIdentityClientId = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTID");
    //     }
    // );
    
    // For service principal.
    // var tenantId = Environment.GetEnvironmentVariable("AZURE_COSMOS_TENANTID");
    // var clientId = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTID");
    // var clientSecret = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTSECRET");
    // var tokenProvider = new ClientSecretCredential(tenantId, clientId, clientSecret);
    
    // Acquire the access token. 
    AccessToken accessToken = await tokenProvider.GetTokenAsync(
        new TokenRequestContext(scopes: new string[]{ scope }));
    
    // Get the connection string.
    var httpClient = new HttpClient();
    httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {accessToken.Token}");
    var response = await httpClient.POSTAsync(listConnectionStringUrl);
    var responseBody = await response.Content.ReadAsStringAsync();
    var connectionStrings = JsonConvert.DeserializeObject<Dictionary<string, List<Dictionary<string, string>>>(responseBody);
    var connectionString = connectionStrings["connectionStrings"].Find(connStr => connStr["description"] == "Primary Table Connection String")["connectionString"];
    
    // Connect to Azure Cosmos DB for Table
    TableServiceClient tableServiceClient = new TableServiceClient(connectionString);
    

User-assigned managed identity

Default environment variable name Description Example value
AZURE_COSMOS_LISTCONNECTIONSTRINGURL The URL to get the connection string https://management.azure.com/subscriptions/<subscription-ID>/resourceGroups/<resource-group-name>/providers/Microsoft.DocumentDB/databaseAccounts/<table-name>/listConnectionStrings?api-version=2021-04-15
AZURE_COSMOS_SCOPE Your managed identity scope https://management.azure.com/.default
AZURE_COSMOS_CLIENTID Your client secret ID <client-ID>
AZURE_COSMOS_RESOURCEENDPOINT Your resource endpoint https://<table-name>.documents.azure.com:443/

Sample code

To connect using a user-assigned managed identity, the following code uses the managed identity to retrieve the connection string, then establishes the connection:

  1. Install dependencies.
    dotnet add package Azure.Data.Tables
    dotnet add package Azure.Identity
    
  2. Get an access token for the managed identity or service principal using Azure.Identity. Use the access token and AZURE_COSMOS_LISTCONNECTIONSTRINGURL to get the connection string and connect to Azure Cosmos DB for Table. In the code below, uncomment the section for your authentication type:
    using System;
    using System.Security.Authentication;
    using System.Net.Security;
    using System.Net.Http;
    using System.Security.Authentication;
    using System.Threading.Tasks;
    using Azure.Data.Tables;
    using Azure.Identity;
    
    var endpoint = Environment.GetEnvironmentVariable("AZURE_COSMOS_RESOURCEENDPOINT");
    var listConnectionStringUrl = Environment.GetEnvironmentVariable("AZURE_COSMOS_LISTCONNECTIONSTRINGURL");
    var scope = Environment.GetEnvironmentVariable("AZURE_COSMOS_SCOPE");
    
    // Uncomment the following lines corresponding to the authentication type you want to use.
    // For system-assigned identity.
    // var tokenProvider = new DefaultAzureCredential();
    
    // For user-assigned identity.
    // var tokenProvider = new DefaultAzureCredential(
    //     new DefaultAzureCredentialOptions
    //     {
    //         ManagedIdentityClientId = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTID");
    //     }
    // );
    
    // For service principal.
    // var tenantId = Environment.GetEnvironmentVariable("AZURE_COSMOS_TENANTID");
    // var clientId = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTID");
    // var clientSecret = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTSECRET");
    // var tokenProvider = new ClientSecretCredential(tenantId, clientId, clientSecret);
    
    // Acquire the access token. 
    AccessToken accessToken = await tokenProvider.GetTokenAsync(
        new TokenRequestContext(scopes: new string[]{ scope }));
    
    // Get the connection string.
    var httpClient = new HttpClient();
    httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {accessToken.Token}");
    var response = await httpClient.POSTAsync(listConnectionStringUrl);
    var responseBody = await response.Content.ReadAsStringAsync();
    var connectionStrings = JsonConvert.DeserializeObject<Dictionary<string, List<Dictionary<string, string>>>(responseBody);
    var connectionString = connectionStrings["connectionStrings"].Find(connStr => connStr["description"] == "Primary Table Connection String")["connectionString"];
    
    // Connect to Azure Cosmos DB for Table
    TableServiceClient tableServiceClient = new TableServiceClient(connectionString);
    

Connection string

Default environment variable name Description Example value
AZURE_COSMOS_CONNECTIONSTRING Azure Cosmos DB for Table connection string DefaultEndpointsProtocol=https;AccountName=<account-name>;AccountKey=<account-key>;TableEndpoint=https://<table-name>.table.cosmos.azure.com:443/;

Warning

Microsoft recommends that you use the most secure authentication flow available. The authentication flow described in this procedure requires a very high degree of trust in the application, and carries risks that are not present in other flows. You should only use this flow when other more secure flows, such as managed identities, aren't viable.

Sample code

To connect using a connection string:

  1. Install dependency.

    dotnet add package Azure.Data.Tables
    
  2. Get the connection string from the environment variable added by Service Connector.

    using Azure.Data.Tables;
    using System; 
    
    TableServiceClient tableServiceClient = new TableServiceClient(Environment.GetEnvironmentVariable("AZURE_COSMOS_CONNECTIONSTRING"));
    

Service principal

Default environment variable name Description Example value
AZURE_COSMOS_LISTCONNECTIONSTRINGURL The URL to get the connection string https://management.azure.com/subscriptions/<subscription-ID>/resourceGroups/<resource-group-name>/providers/Microsoft.DocumentDB/databaseAccounts/<table-name>/listConnectionStrings?api-version=2021-04-15
AZURE_COSMOS_SCOPE Your managed identity scope https://management.azure.com/.default
AZURE_COSMOS_CLIENTID Your client secret ID <client-ID>
AZURE_COSMOS_CLIENTSECRET Your client secret <client-secret>
AZURE_COSMOS_TENANTID Your tenant ID <tenant-ID>
AZURE_COSMOS_RESOURCEENDPOINT Your resource endpoint https://<table-name>.documents.azure.com:443/

Sample code

To connect using a service principal:

  1. Install dependencies.
    dotnet add package Azure.Data.Tables
    dotnet add package Azure.Identity
    
  2. Get an access token for the managed identity or service principal using Azure.Identity. Use the access token and AZURE_COSMOS_LISTCONNECTIONSTRINGURL to get the connection string and connect to Azure Cosmos DB for Table. In the code below, uncomment the section for your authentication type:
    using System;
    using System.Security.Authentication;
    using System.Net.Security;
    using System.Net.Http;
    using System.Security.Authentication;
    using System.Threading.Tasks;
    using Azure.Data.Tables;
    using Azure.Identity;
    
    var endpoint = Environment.GetEnvironmentVariable("AZURE_COSMOS_RESOURCEENDPOINT");
    var listConnectionStringUrl = Environment.GetEnvironmentVariable("AZURE_COSMOS_LISTCONNECTIONSTRINGURL");
    var scope = Environment.GetEnvironmentVariable("AZURE_COSMOS_SCOPE");
    
    // Uncomment the following lines corresponding to the authentication type you want to use.
    // For system-assigned identity.
    // var tokenProvider = new DefaultAzureCredential();
    
    // For user-assigned identity.
    // var tokenProvider = new DefaultAzureCredential(
    //     new DefaultAzureCredentialOptions
    //     {
    //         ManagedIdentityClientId = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTID");
    //     }
    // );
    
    // For service principal.
    // var tenantId = Environment.GetEnvironmentVariable("AZURE_COSMOS_TENANTID");
    // var clientId = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTID");
    // var clientSecret = Environment.GetEnvironmentVariable("AZURE_COSMOS_CLIENTSECRET");
    // var tokenProvider = new ClientSecretCredential(tenantId, clientId, clientSecret);
    
    // Acquire the access token. 
    AccessToken accessToken = await tokenProvider.GetTokenAsync(
        new TokenRequestContext(scopes: new string[]{ scope }));
    
    // Get the connection string.
    var httpClient = new HttpClient();
    httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {accessToken.Token}");
    var response = await httpClient.POSTAsync(listConnectionStringUrl);
    var responseBody = await response.Content.ReadAsStringAsync();
    var connectionStrings = JsonConvert.DeserializeObject<Dictionary<string, List<Dictionary<string, string>>>(responseBody);
    var connectionString = connectionStrings["connectionStrings"].Find(connStr => connStr["description"] == "Primary Table Connection String")["connectionString"];
    
    // Connect to Azure Cosmos DB for Table
    TableServiceClient tableServiceClient = new TableServiceClient(connectionString);
    

Next steps

Follow the tutorials listed below to learn more about Service Connector.