Bridge Google Cloud Storage Connectivity with Apache NiFi

Apache NiFi supports powerful and scalable directed graphs of data routing, transformation, and system mediation logic. When paired with the CData JDBC Driver for Google Cloud Storage, NiFi can work with live Google Cloud Storage data. This article describes how to connect to and query Google Cloud Storage data from an Apache NiFi Flow.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live Google Cloud Storage data. When you issue complex SQL queries to Google Cloud Storage, the driver pushes supported SQL operations, like filters and aggregations, directly to Google Cloud Storage and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying allows you to work with and analyze Google Cloud Storage data using native data types.

Connecting to Google Cloud Storage Data in Apache NiFi

1. Download the CData JDBC Driver for Google Cloud Storage installer, unzip the package, run the .exe file to install the driver.

2. Copy the CData JDBC Driver JAR file (and license file if it exists), cdata.jdbc.googlecloudstorage.jar (and cdata.jdbc.googlecloudstorage.lic), to the Apache NiFi lib subfolder, for example, C:\nifi-1.3.0-bin\nifi-1.3.0\lib.

   On Windows, the default location for the CData JDBC Driver is C:\Program Files\CData\CData JDBC Driver for Google Cloud Storage.

3. Start Apache NiFi by running the run-nifi.bat file in bin subfolder, for example, C:\nifi-1.3.0-bin\nifi-1.3.0\bin.

   (OR)

   Use the command prompt to navigate to the particular directory and run the run-nifi.bat file for example:

   cd C:\nifi-1.3.0-bin\nifi-1.3.0\bin
   .\run-nifi.bat
   

4. Navigate to the Apache NiFi UI in your web browser: It should be https://localhost:8443/nifi.

   Note: If users are utilizing an older version of Apache NiFi, they should access it via http://localhost:8080/nifi. In earlier versions, HTTP was the protocol employed. However, in the most recent version, HTTPS is the standard. By default, HTTP operates on port 8080, while HTTPS uses port 8443.

5. When accessing Apache NiFi via a URL, it prompts you to enter a username and password for login.

   To retrieve login credentials, users should consult the 'App.log' file located within the log directory of their NiFi installation. This file typically contains the necessary details for accessing the NiFi interface.

6. Click the (Configuration) button from the Operate sidebar under the "NiFi Flow" process group.
7. In the NiFi Flow Configuration page, navigate to the "Controller Services" tab.
8. Click the button to create a new controller service.
9. In the Add Controller Service page, select "DBCPConnectionPool", and then click Add.
10. In the Configure Controller Service page, navigate to the "Properties" tab.
11. Click the gear button to configure the new DBCPConnection Pool.

12. Fill in the properties:

    Property	Value
    Database Connection URL	jdbc:googlecloudstorage:ProjectId='project1';InitiateOAuth=GETANDREFRESH
    Database Driver Class Name	cdata.jdbc.googlecloudstorage.GoogleCloudStorageDriver
    Database Driver Location(s)	Path to your Apache NiFi's lib folder where the JAR files are present.

    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.

    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.

13. To establish a connection and execute a select query, simply drag and drop the processor (indicated by the yellow highlight) into the workspace.
14. Select the 'ExecuteSQL' processor and click the 'Add' button to make it visible in the workspace.
15. Click on the added processor (ExecuteSQL)to open the connection page.
16. Click on the Verify Properties button and verify to test the connection.
17. Ensure that all the verification results are successful, and then click on APPLY.
18. Activate the connection by clicking the small button at the right corner of the screen.

Your Google Cloud Storage data is now available for use in Apache NiFi. For example, you can use the DBCPConnection Pool as the source for a QueryDatabaseTable processor (shown below).

Download a free, 30-day trial of the CData JDBC Driver for Google Cloud Storage and start working with your live Google Cloud Storage data in Apache NiFi. Reach out to our Support Team if you have any questions.