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

Connect to Presto from Axios

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

(Optional) Add a New Connect Cloud User

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

Navigate to the Users page and click Invite Users

Enter the new user's email address and click Send to invite the user

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.

Click on your username at the top right of the Connect Cloud app and click User Profile.

On the User Profile page, scroll down to the Personal Access Tokens section and click Create PAT.

Give your PAT a name and click Create.

The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

Connect to Presto from Connect Cloud

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

Log into Connect Cloud, click Connections and click Add Connection

Select "Presto" from the Add Connection panel

Enter the necessary authentication properties to connect to Presto.

Set the Server and Port connection properties to connect, in addition to any authentication properties that may be required.

To enable TLS/SSL, set UseSSL to true.

Authenticating with LDAP

In order to authenticate with LDAP, set the following connection properties:

AuthScheme: Set this to LDAP.
User: The username being authenticated with in LDAP.
Password: The password associated with the User you are authenticating against LDAP with.

Authenticating with Kerberos

In order to authenticate with KERBEROS, set the following connection properties:

AuthScheme: Set this to KERBEROS.
KerberosKDC: The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
KerberosRealm: The Kerberos Realm used to authenticate the user with.
KerberosSPN: The Service Principal Name for the Kerberos Domain Controller.
KerberosKeytabFile: The Keytab file containing your pairs of Kerberos principals and encrypted keys.
User: The user who is authenticating to Kerberos.
Password: The password used to authenticate to Kerberos.

Configuring a connection (Salesforce is shown)

Click Create & Test

Navigate to the Permissions tab in the Add Presto 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 Presto through common web requests. To work with Presto data in Axios web apps, you will use the query endpoint.

Query Endpoint

https://cloud.cdata.com/api/query

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

Connect to Presto Data in Axios Workflows

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

Create a project directory for your web app. For example: ~/connect_cloud/

Open a terminal, navigate the the project directory and initialize a node project using the command: npm init -y

Install the Axios dependency in the project using the following command: npm install axios

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 Presto1.SCHEMA.Customer.

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 Presto1.SCHEMA.Customer"
};

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);
});

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 }
    ...