How can I run SQL on PostgreSQL RDS from Lambda function in Node.js?

Question

I have this code in Lambda funcion:

sql="SELECT ...";
var pg = require('pg');
var connectionString = 'postgres://...';

var client = new pg.Client(connectionString);
client.connect();
var query = client.query(sql);
query.on('end', function() { client.end(); });

When I run from EC2, it works fine. When I run from Lambda I get Error: Cannot find module 'pg'

Answer 1

I am a super noob in Node JS, but I really wanted to try AWS Lambda. Here are the steps I took. I used a Ubuntu 14.04.

sudo apt-get update
sudo apt-get install nodejs
sudo apt-get install npm
sudo ln -s /usr/bin/nodejs /usr/bin/node

mkdir the_function && cd the_function
mkdir node_modules 
npm install pg

******Now create a file index.js and paste the content of your funcion.
console.log('Loading S2 Function');
var pg = require("pg");

exports.handler = function(event, context) {   
    var conn = "pg://user:password@host:5432/bd_name";

    var client = new pg.Client(conn);
    client.connect();

    var query = client.query("SELECT * FROM BLA WHERE ID = 1");
    query.on("row", function (row, result) {
        result.addRow(row);
    });
    query.on("end", function (result) {
        var jsonString = JSON.stringify(result.rows);
        var jsonObj = JSON.parse(jsonString);
        console.log(jsonString);
        client.end();
        context.succeed(jsonObj);
    });
 };

******Now zip the contents of the_function folder (not the_function folder itself)

You can check the official sample from this AWS link: http://docs.aws.amazon.com/lambda/latest/dg/walkthrough-s3-events-adminuser-create-test-function-create-function.html