AWS lambda example to write/read, ref: https://stackoverflow.com/a/35007461/7354486

lambda.js

// ref: https://stackoverflow.com/a/35007461/7354486
var tester = require("./test.js");

console.log("test2");

console.log("first line2");
exports.handler3 = (event, context, callback) => {
    console.log("event2:", event);
    tester.test5();
    // TODO implement
    // callback(null, 'Hello from2');
};

var fs = require("fs");

exports.testIO = function(event, context) {
    const fileName = "/tmp/test.txt";
    fs.writeFile(fileName, "testing", function (err) {
        if (err) {
            context.fail("writeFile failed: " + err);
        } else {
            context.succeed("writeFile succeeded");
            //read it 
              // const houseprice = JSON.parse(fs.readFileSync(fileName, 'utf8'));
            const houseprice = fs.readFileSync(fileName, 'utf8');
            console.log("price:", houseprice);
        }
    });
};