Build AlloyDB-Connected Apps in Mendix

Mendix is a high-productivity app platform that allows you to build and maintain both mobile and web applications at-scale. When paired with CData Connect Cloud, Mendix provides instant, cloud-to-cloud access to AlloyDB data for applications. This article demonstrates how to connect to a CData Connect Cloud data source from within Mendix.

CData Connect Cloud provides a pure cloud-to-cloud interface for AlloyDB, allowing you to import data from live AlloyDB data in Mendix — without replicating the data to a natively supported database. As you build web and mobile applications from within Mendix, CData Connect Cloud pushes all supported SQL operations (filters, JOINs, etc.) directly to AlloyDB, leveraging server-side processing to return the requested AlloyDB data quickly.

Configure AlloyDB Connectivity for Mendix

Connectivity to AlloyDB from Mendix is made possible through CData Connect Cloud. To work with AlloyDB data from Mendix, we start by creating and configuring a AlloyDB connection.

1. Log into Connect Cloud, click Connections and click Add Connection
2. Select "AlloyDB" from the Add Connection panel
3. Enter the necessary authentication properties to connect to AlloyDB.

   The following connection properties are usually required in order to connect to AlloyDB.

   • Server: The host name or IP of the server hosting the AlloyDB database.
   • User: The user which will be used to authenticate with the AlloyDB server.
   • Password: The password which will be used to authenticate with the AlloyDB server.

   You can also optionally set the following:

   • Database: The database to connect to when connecting to the AlloyDB Server. If this is not set, the user's default database will be used.
   • Port: The port of the server hosting the AlloyDB database. This property is set to 5432 by default.

   Authenticating with Standard Authentication

   Standard authentication (using the user/password combination supplied earlier) is the default form of authentication.

   No further action is required to leverage Standard Authentication to connect.

   Authenticating with pg_hba.conf Auth Schemes

   There are additional methods of authentication available which must be enabled in the pg_hba.conf file on the AlloyDB server.

   Find instructions about authentication setup on the AlloyDB Server here.

   Authenticating with MD5 Authentication

   This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to md5.

   Authenticating with SASL Authentication

   This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to scram-sha-256.

   Authenticating with Kerberos

   The authentication with Kerberos is initiated by AlloyDB Server when the ∏ is trying to connect to it. You should set up Kerberos on the AlloyDB Server to activate this authentication method. Once you have Kerberos authentication set up on the AlloyDB Server, see the Kerberos section of the help documentation for details on how to authenticate with Kerberos.

4. Click Create & Test
5. Navigate to the Permissions tab in the Add AlloyDB Connection page and update the User-based permissions.

Add AlloyDB OData Endpoints in Connect Cloud

After connecting to AlloyDB, create OData Endpoints for the desired table(s).

1. Navigate to the OData page and click Add to create new OData endpoints
2. Select the AlloyDB connection (e.g. AlloyDB1) and click Next
3. Select the table(s) you wish to work with and click Confirm

With the connection and OData endpoints configured, you are ready to connect to AlloyDB data from Mendix.

Build a AlloyDB-Connected App

With OData endpoints added to Connect Cloud, you can build an app in Mendix with live access to AlloyDB data.

Downloading the OData Metadata File

When creating a connection in Mendix, the connection flow requires a Data Source Contract File. Follow these steps to download the OData metadata file for CData Connect Cloud using curl, a command line tool:

1. Open a command-line window for your operating system. On Windows, open the start menu, type cmd, and press the Enter key to open a command prompt. On macOS and Linux, open a Terminal window.
2. To check if curl is installed on your system, type curl -help and press the enter key. If it is not installed, install it from the curl website.
3. Issue the following curl command, replacing USER with your CData Connect Cloud username and PAT with the PAT you generated above: curl -u USER:PAT https://cloud.cdata.com/api/odata/service/$metadata -o metadata.xml
4. Locate the metadata.xml file that the curl command created and move it to an accessible location.

Connecting to CData Connect Cloud in Mendix

Follow these steps to establish a connection from Mendix to CData Connect Cloud:

1. Login to Mendix and open the Data Hub page.
2. In the Register a Data Source section, select OData.
3. Upload the metadata.xml file from the steps above and click Next.
4. Enter your desired values for Data Source Name and Data Source Version. In the Data Source Relative Path field, enter /api/odata/service and click Next.
5. On the Application information page, click Register a new application.
6. Enter a name in Application Name and select a technical owner (by default, this is the user who is currently logged in).
7. Click Next. In the Environment Name field, enter a desired name (for example, CData Connect Cloud). In the Environment Location field, enter https://cloud.cdata.com and select the appropriate Environment Type (e.g. Production), depending on what is needed.
8. Click Done! to create your connection.

You can now use your connection in Mendix Studio Pro to easily create applications with access to live AlloyDB data.

Get CData Connect Cloud

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