Query Elasticsearch Data as a SQL Server Database in Node.js

You can use CData Connect Cloud to query Elasticsearch data through a SQL Server interface. Follow the procedure below to create a virtual database for Elasticsearch in Connect Cloud and start querying using Node.js.

CData Connect Cloud provides a pure MySQL, cloud-to-cloud interface for Elasticsearch, allowing you to easily query live Elasticsearch data in Node.js — without replicating the data to a natively supported database. As you query data in Node.js, CData Connect Cloud pushes all supported SQL operations (filters, JOINs, etc) directly to Elasticsearch, leveraging server-side processing to quickly return Elasticsearch data.

Getting Started

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Configure Elasticsearch Connectivity for NodeJS

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

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

   Set the Server and Port connection properties to connect. To authenticate, set the User and Password properties, PKI (public key infrastructure) properties, or both. To use PKI, set the SSLClientCert, SSLClientCertType, SSLClientCertSubject, and SSLClientCertPassword properties.

   The data provider uses X-Pack Security for TLS/SSL and authentication. To connect over TLS/SSL, prefix the Server value with 'https://'. Note: TLS/SSL and client authentication must be enabled on X-Pack to use PKI.

   Once the data provider is connected, X-Pack will then perform user authentication and grant role permissions based on the realms you have configured.

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

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.

With the connection configured, you are ready to connect to Elasticsearch data from Node.js.

Query Elasticsearch from Node.js

The following example shows how to define a connection and execute queries to Elasticsearch with the SQL Server module. You will need the following information:

• server: tds.cdata.com
• port: 14333
• user: a Connect Cloud user (e.g. user@mydomain.com)
• password: the PAT for the above user
• database: The connection you configured for Elasticsearch (Elasticsearch1)

Connect to Elasticsearch data and start executing queries with the code below:

var sql = require('mssql')
var config = {
	server: 'tds.cdata.com',
	port: 14333, 
	user: 'user@mydomain.com', //update me
	password: 'CONNECT_USER_PAT', //update me	
	options: {
		encrypt: true,
		database: 'Elasticsearch1'
	}
}

sql.connect(config, err => { 
    if(err){
        throw err ;
    }
    new sql.Request().query('SELECT * FROM Orders', (err, result) => {
        console.dir(result)
    })
        
});

sql.on('error', err => {
    console.log("SQL Error: " ,err);
})