Build Databricks-Connected Web Apps with Axios and CData Connect Cloud

Axios is a JavaScript library that allows developers to make HTTP requests to servers from a web browser or Node.js. When paired with CData Connect Cloud, you get access to live Databricks data for your web apps. This article shows how to connect to Databricks and build web apps in Axios with access to live Databricks data.

Getting Started

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Connect to Databricks from Axios

To work with Databricks in Axios, we need to connect to Databricks from Connect Cloud, provide user access to the connection, and create OData endpoints for the Databricks data.

(Optional) Add a New Connect Cloud User

As needed, create Users to connect to Databricks through Connect Cloud.

1. Navigate to the Users page and click Invite Users
2. Enter the new user's email address and click Send to invite the user
3. You can review and edit users from the Users page

Add a Personal Access Token

If you are connecting from a service, application, platform, or framework that does not support OAuth authentication, you can create a Personal Access Token (PAT) to use for authentication. Best practices would dictate that you create a separate PAT for each service, to maintain granularity of access.

1. Click on your username at the top right of the Connect Cloud app and click User Profile.
2. On the User Profile page, scroll down to the Personal Access Tokens section and click Create PAT.
3. Give your PAT a name and click Create.
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

Connect to Databricks from Connect Cloud

CData Connect Cloud uses a straightforward, point-and-click interface to connect to data sources.

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

   To connect to a Databricks cluster, set the properties as described below.

   Note: The needed values can be found in your Databricks instance by navigating to Clusters, and selecting the desired cluster, and selecting the JDBC/ODBC tab under Advanced Options.

   • Server: Set to the Server Hostname of your Databricks cluster.
   • HTTPPath: Set to the HTTP Path of your Databricks cluster.
   • Token: Set to your personal access token (this value can be obtained by navigating to the User Settings page of your Databricks instance and selecting the Access Tokens tab).
4. Click Create & Test
5. Navigate to the Permissions tab in the Add Databricks Connection page and update the User-based permissions.

Note the CData Connect Cloud SQL API Endpoint(s)

CData Connect Cloud contains API endpoints that allow you to submit SQL queries to Databricks through common web requests. To work with Databricks data in Axios web apps, you will use the query endpoint.

Query Endpoint

With the connection and Workspace configured, you are ready to connect to Databricks data from Axios.

Connect to Databricks Data in Axios Workflows

To establish a connection from Axios to CData Connect Cloud using the OData protocol, follow these steps.

1. Create a project directory for your web app. For example: ~/connect_cloud/
2. Open a terminal, navigate the the project directory and initialize a node project using the command: npm init -y
3. Install the Axios dependency in the project using the following command: npm install axios

4. In your project directory, create a file called server.js that contains the following code. Provide your CData Connect Cloud username (e.g. [email protected]) and PAT (the PAT you created in the prerequisites). You must also provide a query for your data, such as SELECT * FROM Databricks1.SCHEMA.Customers.

   server.js code

   const axios = require('axios') const user = '[email protected]' const pat = '***********************************'; //Your API endpoint const url = 'https://cloud.cdata.com/api/query'; //Your data to be sent in the POST request const data = { "query":"SELECT * FROM Databricks1.SCHEMA.Customers" }; axios.post(url, data, { auth: { username: user, password: pat } }) .then(response => { const rows = response.data.results[0].rows; const schema = response.data.results[0].schema; //Create an array of column names const columnNames = schema.map(col => col.columnName); //Loop through each row and log the column name with its value rows.forEach(row => { const rowObject = {}; row.forEach((value, index) => { const columnName = columnNames[index]; rowObject[columnName] = value; }); console.log(rowObject); }) }) .catch(error => { console.error('Error:', error); });
5. In the terminal, execute the following command to run the server: node server.js The query results will appear: { ID: 1, VALUE: -2 } { ID: 2, VALUE: 1 } { ID: 11, VALUE: null } { ID: 3, VALUE: 2 } { ID: 4, VALUE: 5 } ...

Simplified Access to Databricks Data from Cloud Applications

At this point, you have a direct connection to live Databricks data from Axios. For more information on gaining simplified access to data from more than 100 SaaS, Big Data, and NoSQL sources in cloud applications like Axios, refer to our Connect Cloud page.