how to set up a layer for node-oracledb package in aws lambda environment?

Question

I want to connect to oracle database hosted in RDS inside aws lambda nodejs runtime . after research i found out that i need to download node-oracledb package and create a layer for node module and binary lib files. so i created folder structure as shown below, and zip folder and uploaded to aws layer and attached layer to lambda, however i get "errorMessage": "Cannot find module 'oracledb' any clue Why AWS node cannot find module?, thank you

Lambda-Layer-1(version 1)
|
|__lib
|     |__libaio.so.1
|     |__libclntsh.so.12.1
|     |__libclntschcore.so.12.1
|     |__libipc1.so
|     |__libmql1.so
|     |__libnnz12.so
|     |__libociicus.so
|     |__libons.so
|
|__nodejs
      |
      |__node_modules
               |
               |__oracledb

Error from lambda:

  "errorMessage": "Cannot find module 'oracledb'",
  "errorType": "Error",
  "stackTrace": [
    "Module.require (module.js:596:17)",
    "require (internal/module.js:11:18)",
    "Object.<anonymous> (/var/task/src/services/oracleDb.service.js:10:18)",
    "Module._compile (module.js:652:30)",
    "Object.Module._extensions..js (module.js:663:10)",
    "Module.load (module.js:565:32)",



AWS runtime: 
Nodejs:8.10 
node-oracledb:"3.1.2"

code:

 const oracledb = require("oracledb");
  let connection;
    static async init() {
        try {
            if (!connection) {
                const connectionAtrribute = {
                    connectionString: 'uat-*******',
                    password: '*******',
                    user: '*******'
                };
                connection = await oracledb.getConnection(connectionAtrribute);
            }
        }
        catch (error) {
            console.log('ERROR', JSON.stringify(error));
        }
    }

Answer 1

There is an another library “oracledb_for_lambda” to connect oracle DB from lambda

npm i oracledb-for-lambda

Now, In the Project folder, Create a folder named “nodejs” and You need to move the “node_modules” folder into this “nodejs” folder. Then, Copy the “lib” folder inside “/node_modules/oracledb-for-lambda” and paste it outside in the main project directory.

Finally, you will get a folder structure like the below image.

That’s it, Zip the files inside the folder and Upload the Zip to S3

And you can connect using below code

'use strict';
var os = require('os');
var fs = require('fs');
var oracledb = require('oracledb-for-lambda');
exports.handler = async (event, context) => {
    let str_host = os.hostname() + ' localhost\n';
    fs.writeFileSync(process.env.HOSTALIASES, str_host, function(err) {
        if (err) throw err;
    });
    var connAttr = {
        user: process.env.USERNAME,
        password: process.env.PASSWORD,
        connectString: process.env.CONNECTION_STRING
    };

    const promise = new Promise(function(resolve, reject) {
        oracledb.getConnection(connAttr, function(err, connection) {
            if (err) {
                reject({
                    status: "ERROR"
                });
            }
            resolve({
                status: "SUCCESS"
            });
        });
    });
    return promise;
}