Access Google Cloud Storage Data in Mule Applications Using the CData JDBC Driver

The CData JDBC Driver for Google Cloud Storage connects Google Cloud Storage data to Mule applications enabling read functionality with familiar SQL queries. The JDBC Driver allows users to easily create Mule applications to backup, transform, report, and analyze Google Cloud Storage data.

This article demonstrates how to use the CData JDBC Driver for Google Cloud Storage inside of a Mule project to create a Web interface for Google Cloud Storage data. The application created allows you to request Google Cloud Storage data using an HTTP request and have the results returned as JSON. The exact same procedure outlined below can be used with any CData JDBC Driver to create a Web interface for the hundreds of available data sources.

1. Create a new Mule Project in Anypoint Studio.
2. Add an HTTP Connector to the Message Flow.
3. Configure the address for the HTTP Connector. 👁 Add and Configure the HTTP Connector
   
4. Add a Database Select Connector to the same flow, after the HTTP Connector.
5. Create a new Connection (or edit an existing one) and configure the properties.
   • Set Connection to "Generic Connection"
   • Select the CData JDBC Driver JAR file in the Required Libraries section (e.g. cdata.jdbc.googlecloudstorage.jar). 👁 Adding the JAR file (Salesforce is shown).
     
   • Set the URL to the connection string for Google Cloud Storage

     Authenticate with a User Account

     You can connect without setting any connection properties for your user credentials. After setting InitiateOAuth to GETANDREFRESH, you are ready to connect.

     When you connect, the Google Cloud Storage OAuth endpoint opens in your default browser. Log in and grant permissions, then the OAuth process completes

     Authenticate with a Service Account

     Service accounts have silent authentication, without user authentication in the browser. You can also use a service account to delegate enterprise-wide access scopes.

     You need to create an OAuth application in this flow. See the Help documentation for more information. After setting the following connection properties, you are ready to connect:

     • InitiateOAuth: Set this to GETANDREFRESH.
     • OAuthJWTCertType: Set this to "PFXFILE".
     • OAuthJWTCert: Set this to the path to the .p12 file you generated.
     • OAuthJWTCertPassword: Set this to the password of the .p12 file.
     • OAuthJWTCertSubject: Set this to "*" to pick the first certificate in the certificate store.
     • OAuthJWTIssuer: In the service accounts section, click Manage Service Accounts and set this field to the email address displayed in the service account Id field.
     • OAuthJWTSubject: Set this to your enterprise Id if your subject type is set to "enterprise" or your app user Id if your subject type is set to "user".
     • ProjectId: Set this to the Id of the project you want to connect to.

     The OAuth flow for a service account then completes.

     Built-in Connection String Designer

     For assistance in constructing the JDBC URL, use the connection string designer built into the Google Cloud Storage JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

     		java -jar cdata.jdbc.googlecloudstorage.jar
     		

     Fill in the connection properties and copy the connection string to the clipboard.

   • Set the Driver class name to cdata.jdbc.googlecloudstorage.GoogleCloudStorageDriver. 👁 A configured Database Connection (Salesforce is shown).
     
   • Click Test Connection.
6. Set the SQL Query Text to a SQL query to request Google Cloud Storage data. For example:

   SELECT Name, OwnerId FROM Buckets WHERE Name = 'TestBucket'

   👁 Configure the Select object (Salesforce is Shown)
   
7. Add a Transform Message Component to the flow.
8. Set the Output script to the following to convert the payload to JSON:

   %dw 2.0
   output application/json
   ---
   payload
    

   👁 Add the Transform Message Component to the Flow
   
9. To view your Google Cloud Storage data, navigate to the address you configured for the HTTP Connector (localhost:8081 by default): http://localhost:8081. The Google Cloud Storage data is available as JSON in your Web browser and any other tools capable of consuming JSON endpoints.

At this point, you have a simple Web interface for working with Google Cloud Storage data (as JSON data) in custom apps and a wide variety of BI, reporting, and ETL tools. Download a free, 30 day trial of the JDBC Driver for Google Cloud Storage and see the CData difference in your Mule Applications today.