Connecting to an Amazon RDS database in a Lambda function

Reporting Kinesis batch item failures with Lambda using Javascript.

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
/* 
Node.js code here.
*/
// ES6+ example
import { Signer } from "@aws-sdk/rds-signer";
import mysql from 'mysql2/promise';

async function createAuthToken() {
  // Define connection authentication parameters
  const dbinfo = {

    hostname: process.env.ProxyHostName,
    port: process.env.Port,
    username: process.env.DBUserName,
    region: process.env.AWS_REGION,

  }

  // Create RDS Signer object
  const signer = new Signer(dbinfo);

  // Request authorization token from RDS, specifying the username
  const token = await signer.getAuthToken();
  return token;
}

async function dbOps() {

  // Obtain auth token
  const token = await createAuthToken();
  // Define connection configuration
  let connectionConfig = {
    host: process.env.ProxyHostName,
    user: process.env.DBUserName,
    password: token,
    database: process.env.DBName,
    ssl: 'Amazon RDS'
  }
  // Create the connection to the DB
  const conn = await mysql.createConnection(connectionConfig);
  // Obtain the result of the query
  const [res,] = await conn.execute('select ?+? as sum', [3, 2]);
  return res;

}

export const handler = async (event) => {
  // Execute database flow
  const result = await dbOps();
  // Return result
  return {
    statusCode: 200,
    body: JSON.stringify("The selected sum is: " + result[0].sum)
  }
};