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Build a Node.js application

Yugabyte Cloud requires SSL

Are you using Yugabyte Cloud? Install the prerequisites, then go to the Use Node.js with SSL section.

Prerequisites

This tutorial assumes that you have:

installed YugabyteDB and created a cluster. Refer to Quick Start.
installed a recent version of node.
installed the node-postgres driver.
installed the async utility to work with asynchronous Javascript.

To install the node-postgres driver, run the following command:

$ npm install pg

To install the async utility, run the following command:

$ npm install --save async

Create a sample Node.js application

Create a file yb-ysql-helloworld.js and copy the following content to it.

var pg = require('pg');
const async = require('async');
const assert = require('assert');

var conString = "postgres://postgres@localhost:5433/postgres";
var client = new pg.Client(conString);

async.series([
  function connect(next) {
    client.connect(next);
  },
  function createTable(next) {
    // The create table statement.
    const create_table = 'CREATE TABLE employee (id int PRIMARY KEY, ' +
                                                 'name varchar, ' +
                                                 'age int, ' +
                                                 'language varchar);';
    // Create the table.
    console.log('Creating table employee');
    client.query(create_table, next);
  },
  function insert(next) {
    // Create a variable with the insert statement.
    const insert = "INSERT INTO employee (id, name, age, language) " +
                                        "VALUES (1, 'John', 35, 'NodeJS');";
    // Insert a row with the employee data.
    console.log('Inserting row with: %s', insert)
    client.query(insert, next);
  },
  function select(next) {
    // Query the row for employee id 1 and print the results to the console.
    const select = 'SELECT name, age, language FROM employee WHERE id = 1;';
    client.query(select, function (err, result) {
      if (err) return next(err);
      var row = result.rows[0];
      console.log('Query for id=1 returned: name=%s, age=%d, language=%s',
                                            row.name, row.age, row.language);
      next();
    });
  }
], function (err) {
  if (err) {
    console.error('There was an error', err.message, err.stack);
  }
  console.log('Shutting down');
  client.end();
});

Run the application

To run the application, type the following:

$ node yb-ysql-helloworld.js

You should see the following output.

Creating table employee
Inserting row with: INSERT INTO employee (id, name, age, language) VALUES (1, 'John', 35, 'NodeJS');
Query for id=1 returned: name=John, age=35, language=NodeJS
Shutting down

Use Node.js with SSL

The client driver supports several SSL modes, as follows:

SSL mode	Client driver behavior
disable	Supported
allow	Not supported
prefer	Not supported
require (default)	Supported
verify-ca	Supported (Self-signed certificates aren't supported.)
verify-full	Supported

By default, the driver supports the require SSL mode, in which a root CA certificate isn't required to be configured. This enables SSL communication between the Node.js client and YugabyteDB servers.

const config = {
  user: ' ',
  database: ' ',
  host: ' ',
  password: ' ',
  port: 5433,
  // this object will be passed to the TLSSocket constructor
  ssl: {
    rejectUnauthorized: false,
  },
}

To enable verify-ca SSL mode, you need to provide the path to the root CA certificate. You also need to set the rejectUnauthorized property to true to require root certificate chain validation.

const config = {
  user: ' ',
  database: ' ',
  host: ' ',
  password: ' ',
  port: 5433,
  // this object will be passed to the TLSSocket constructor
  ssl: {
    rejectUnauthorized: true,
    ca: fs.readFileSync('~/.postgresql/root.crt').toString(),
  },
}

In this mode, the driver throws an exception if the server certificate presents as a self-signed certificate:

There was an error self signed certificate in certificate chain Error: self signed certificate in certificate chain

To enable verify-full mode, you need to provide the path to the Root CA certificate, as well as the server name:

const config = {
  user: ' ',
  database: ' ',
  host: ' ',
  password: ' ',
  port: 5433,
  // this object will be passed to the TLSSocket constructor
  ssl: {
    rejectUnauthorized: true,
    ca: fs.readFileSync('/Users/my-user/.postgresql/root.crt').toString(),
    servername: 'yugabyte-cloud/my-instance'
  },
}

Create a sample Node.js application with SSL

Create a file yb-ysql-helloworld-ssl.js and copy the following content to it, replacing the values in the config object as appropriate for your cluster:

var pg = require('pg');
const async = require('async');
const assert = require('assert');
const fs = require('fs');
const config = {
  user: 'admin',
  database: 'yugabyte',
  host: '22420e3a-768b-43da-8dcb-xxxxxx.aws.ybdb.io',
  password: 'xxxxxx',
  port: 5433,
  // this object will be passed to the TLSSocket constructor
  ssl: {
    rejectUnauthorized: false,
  },
}

var client = new pg.Client(config);

async.series([
  function connect(next) {
    client.connect(next);
  },
  function createTable(next) {
    // The create table statement.
    const create_table = 'CREATE TABLE IF NOT EXISTS employee (id int PRIMARY KEY, ' +
                                                               'name varchar, ' +
                                                               'age int, ' +
                                                               'language varchar);';
    // Create the table.
    console.log('Creating table employee');
    client.query(create_table, next);
  },
  function insert(next) {
    // Create a variable with the insert statement.
    const insert = "INSERT INTO employee (id, name, age, language) " +
                                         "VALUES (2, 'John', 35, 'NodeJS + SSL');";
    // Insert a row with the employee data.
    console.log('Inserting row with: %s', insert)
    client.query(insert, next);
  },
  function select(next) {
    // Query the row for employee id 2 and print the results to the console.
    const select = 'SELECT name, age, language FROM employee WHERE id = 2;';
    client.query(select, function (err, result) {
      if (err) return next(err);
      var row = result.rows[0];
      console.log('Query for id=2 returned: name=%s, age=%d, language=%s',
                                            row.name, row.age, row.language);
      next();
    });
  }
], function (err) {
  if (err) {
    console.error('There was an error', err.message, err.stack);
  }
  console.log('Shutting down');
  client.end();
});

Run the application

To run the application, type the following:

$ node yb-ysql-helloworld-ssl.js

You should see the following output.

Creating table employee
Inserting row with: INSERT INTO employee (id, name, age, language) VALUES (2, 'John', 35, 'NodeJS + SSL');
Query for id=2 returned: name=John, age=35, language=NodeJS + SSL
Shutting down