Connecting to Power BI XMLA

To connect, set the Workspace property to a valid PowerBIXMLA workspace (ex: CData).

Authenticating to Power BI XMLA

Azure AD

Azure AD is Microsoft’s multi-tenant, cloud-based directory and identity management service. It is user-based authentication that requires that you set AuthScheme to AzureAD.

Desktop Applications

CData provides an embedded OAuth application that simplifies authentication at the desktop.

Before you connect, set the following variables:

• InitiateOAuth: GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken. CData provides an embedded OAuth application that simplifies authentication at the desktop; that is, in situations where the user is using a local server not connected to the internet.

  You can also authenticate from the desktop via a custom OAuth application, which you configure and register at the Power BI XMLA console. For further information, see Creating a Custom OAuth App.

• Custom Azure AD applications only:
  • OAuthClientId: The client Id assigned when you registered your custom OAuth application.
  • OAuthClientSecret: The client secret assigned when you registered your custom OAuth application.
  • CallbackURL: The redirect URI defined when you registered your custom OAuth application.

When you connect, the adapter opens the Power BI XMLA's OAuth endpoint in your default browser. Log in and grant permissions to the application. The adapter then completes the OAuth process:

1. Extracts the access token from the callback URL and authenticates requests.
2. Obtains a new access token when the old one expires.
3. Saves OAuth values in OAuthSettingsLocation. These values persist across connections.

When the access token expires, the adapter refreshes it automatically.

Web Applications

Authenticating via the Web requires you to create and register a custom OAuth application with Power BI XMLA, as described in Creating a Custom OAuth App. You can then use the adapter to get and manage the OAuth token values.

This section describes how to get the OAuth access token, how to have the driver refresh the OAuth access token automatically, and how to refresh the OAuth access token manually.

Get the OAuth access token:

1. To obtain the OAuthAccessToken, set these connection properties:
   • For authentication using a Client Secret:
     • OAuthClientId: The client Id in your application settings.
     • OAuthClientSecret: The client secret in your application settings.
   • For authentication using a Certificate:
     • OAuthClientId: The client Id in your application settings.
     • OAuthJWTCert: The JWT Certificate store.
     • OAuthJWTCertType: The type of the certificate store specified by OAuthJWTCert.
2. Call stored procedures to complete the OAuth exchange:
   • Call the GetOAuthAuthorizationUrl stored procedure. Set the AuthMode input to WEB and the CallbackURL to the Redirect URI you specified in your application settings. The stored procedure returns the URL to the OAuth endpoint.
   • Navigate to the URL that the stored procedure returned in Step 1. Log in and authorize the web application. You are redirected back to the callback URL.
   • Call the GetOAuthAccessToken stored procedure. Set the AuthMode input to WEB. Set the Verifier input to the code parameter in the query string of the redirect URI.

After you obtain the access and refresh tokens, you can connect to data and refresh the OAuth access token automatically.

Automatic refresh of the OAuth access token:

To have the adapter automatically refresh the OAuth access token, do the following:

1. The first time you connect to data, set these connection parameters:
   • InitiateOAuth: REFRESH.
   • OAuthClientId: The client Id in your custom OAuth application settings.
   • OAuthClientSecret: The client secret in your custom OAuth application settings.
   • OAuthAccessToken: The access token returned by GetOAuthAccessToken.
   • OAuthSettingsLocation: The path where you want the adapter to save the OAuth values, which persist across connections.
2. On subsequent data connections, set:
   • InitiateOAuth
   • OAuthSettingsLocation

Manual refresh of the OAuth access token:

The only value needed to manually refresh the OAUth access token is the OAuth refresh token.

1. To manually refresh the OAuthAccessToken after the ExpiresIn period (returned by GetOAuthAccessToken) has elapsed, call the RefreshOAuthAccessToken stored procedure.
2. Set these connection properties:
   • OAuthClientId: The Client Id in your custom OAuth application settings.
   • OAuthClientSecret: The Client Secret in your custom OAuth application settings.

3. Call RefreshOAuthAccessToken with OAuthRefreshToken set to the OAuth refresh token returned by GetOAuthAccessToken.
4. After the new tokens have been retrieved, set the OAuthAccessToken property to the value returned by RefreshOAuthAccessToken. This opens a new connection.

Store the OAuth refresh token so that you can use it to manually refresh the OAuth access token after it has expired.

Headless Machines

If you need to log in to a resource that resides on a headless machine, you must authenticate on another device that has an internet browser. You can do this in either of the following ways:

• Obtain the OAuthVerifier value as described in Obtain and Exchange a Verifier Code, below.
• Install the adapter on another machine and transfer the OAuth authentication values after you authenticate through the usual browser-based flow.

After you execute either of these options, configure the driver to automatically refresh the access token on the headless machine.

Obtaining and Exchanging a Verifier Code

To obtain a verifier code, you must authenticate at the OAuth authorization URL from a machine with an internet browser, and obtain the OAuthVerifier connection property.

1. Choose one of these options:
   • If you are using the Embedded OAuth Application, click Power BI XMLA OAuth endpoint to open the endpoint in your browser.
   • If you are using a custom OAuth application, set the following properties to create the Authorization URL:
     • InitiateOAuth: OFF.
     • OAuthClientId: The client Id assigned when you registered your application.
     • OAuthClientSecret: The client secret assigned when you registered your application.
     After the Authorization URL is established, call the GetOAuthAuthorizationUrl stored procedure with the appropriate CallbackURL. Open the URL returned by the stored procedure in a browser.

2. Log in and grant permissions to the adapter. You are redirected to the callback URL, which contains the verifier code.
3. Save the value of the verifier code. Later you will set this in the OAuthVerifier connection property.

Next, exchange the OAuth verifier code for OAuth refresh and access tokens.

To obtain the OAuth authentication values, set these properties:

• InitiateOAuth: REFRESH.
• OAuthVerifier: The verifier code.
• OAuthSettingsLocation: The location of the file where the driver saves the OAuth token values that persist across connections.
• Custom applications only:
  • OAuthClientId: (custom applications only) Set this to the client Id in your custom OAuth application settings.
  • OAuthClientSecret: (custom applications only) Set this to the client secret in the custom OAuth application settings.

After the OAuth settings file is generated, re-set the following properties to connect:

• InitiateOAuth: REFRESH.
• OAuthSettingsLocation: The location containing the encrypted OAuth authentication values. Make sure this location grants read and write permissions to the adapter to enable the automatic refreshing of the access token.
• Custom applications only:
  • OAuthClientId: The client Id assigned when you registered your application.
  • OAuthClientSecret: The client secret assigned when you registered your application.

Transferring OAuth Settings

Prior to connecting on a headless machine, you must create and install a connection with the driver on a device that supports an internet browser. Set the connection properties as described in "Desktop Applications" above.

After completing the instructions in "Desktop Applications", the resulting authentication values are encrypted and written to the location specified by OAuthSettingsLocation. The default filename is OAuthSettings.txt.

Once you have successfully tested the connection, copy the OAuth settings file to your headless machine.

On the headless machine, set the following connection properties to connect to data:

• InitiateOAuth: REFRESH.
• OAuthSettingsLocation: The location of your OAuth settings file. Make sure this location gives read and write permissions to the adapter to enable the automatic refreshing of the access token.
• Custom applications only:
  • OAuthClientId: The client Id assigned when you registered your application.
  • OAuthClientSecret: The client secret assigned when you registered your application.

Azure Service Principal

Azure Service Principal is role-based application-based authentication. This means that authentication is done per application, rather than per user. All tasks taken by the app are done without a default user context, but based on the assigned roles. The application access to the resources is controlled through the assigned roles' permissions.

To use Azure Service Principal authentication, you must:

• Set up the ability to assign a role to the authentication application. To do this, create a custom OAuth AD application, as described in Creating a Custom OAuth App.
• Register an application with an Azure AD tenant, to create a new service principal that can be used with the role-based access control, to access resources in your subscription.

Do the following:

1. Create a custom Azure AD application, as described in Creating a Custom OAuth App.
2. Assign a role to the application:
   1. Use the search bar to search for the Subscriptions service.
   2. Open the Subscriptions page.
   3. Select the subscription to which to assign the application.
   4. Open the Access control (IAM).
   5. Select Add > Add role assignment. Power BI XMLA opens the Add role assignment page.
   6. Assign your custom Azure AD application the role of Owner.

Admin Consent

Admin consent occurs when the Admin for an Azure Active Directory tenant grants permissions to a custom application that explicitly requires an admin to consent to the use case.

When creating a new Azure AD application in the Azure Portal, you must specify which permissions the application requires. Some permissions may be marked as "Admin Consent Required". For example, all Groups permissions require Admin Consent. If your application requires admin consent, there are two ways you can do this.

The easiest way to grant admin consent is to have an admin log into portal.azure.com and navigate to the application you have created in App Registrations. Under API Permissions, click Grant Consent. This gives your application permissions on the tenant under which it was created.

If your organization has multiple tenants or you must grant application permissions for other tenants outside your organization, use the GetAdminConsentURL stored procedure to generate the Admin Authorization URL. Unlike the GetOAuthAuthorizationUrl stored procedure, no important information is returned from this endpoint. Rather, after the OAuth application is successfully authorized, it returns a Boolean indicating that permissions have been granted.

After the administrator has approved the OAuth Application, you can continue to authenticate.

Client Credentials

Client credentials refers to a flow in OAuth where there is no direct user authentication taking place. Instead, credentials are created for just the application itself. All tasks taken by the application are done without a default user context. This makes the authentication flow a bit different from the standard flow.

All permissions related to the client OAuth flow require admin consent. This means you cannot use the application embedded with the Power BI XMLA Adapter in the client OAuth flow. You must create your own OAuth application to use client credentials. See Creating a Custom OAuth App for more information.

In your App Registration in portal.azure.com, navigate to API Permissions and select the Microsoft Graph permissions. There are two distinct sets of permissions: Delegated permissions and Application permissions. The permissions used during client credential authentication are under "Application Permissions".

Select the permissions you require for your integration. After you do this, set the following connection properties:

• AuthScheme: AzureServicePrincipal.
• InitiateOAuth: GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
• AzureTenant: The tenant you wish to connect to.
• OAuthGrantType: CLIENT.
• OAuthClientId: The client Id in your application settings.
• OAuthClientSecret: The client secret in your application settings.

Authentication with client credentials takes place automatically like any other connection, except there is no window opened prompting the user. Because there is no user context, there is no need for a browser popup. Connections will take place and be handled internally.

Auth Certificate

Auth Certificate refers to an OAuth flow that uses a certificate to enable server-to-server authentication. All permissions related to the client OAuth flow require admin consent. This means you cannot use the application embedded with the Power BI XMLA Adapter in the client OAuth flow. You must create your own OAuth application to use an OAuth certificate. See Creating a Custom OAuth App for more information.

In your App Registration in portal.azure.com, navigate to API Permissions and select the client Graph permissions. There are two distinct sets of permissions: Delegated permissions and Application permissions. The permissions used during certificate authentication are under "Application Permissions".

Select the permissions that apply to your particular integration. After you do this, set the following connection properties:

• AuthScheme: AzureServicePrincipalCert.
• AzureTenant: The tenant to which you need to connect.
• OAuthJWTCert: The JWT Certificate store.
• OAuthJWTIssuer: The OAuth client Id.
• OAuthJWTCertType: The type of the certificate store specified by OAuthJWTCert.

Certificate authentication takes place automatically. Since there is no user context, there is no pop-up to signal the point at which authentication occurs. Connections are made and handled internally.