Node JS project loading local text\sql file works loacly but not when deployed to AWS as a lambda [duplicate]

Try this, it works for me:

'use strict'

let fs = require("fs");
let path = require("path");

exports.handler = (event, context, callback) => {
        // To debug your problem
        console.log(path.resolve("./readme.txt"));

        // Solution is to use absolute path using `__dirname`
        fs.readFile(__dirname +'/readme.txt', function (err, data) {
            if (err) throw err;
        });
};

to debug why your code is not working, add below link in your handler

console.log(path.resolve("./readme.txt"));

On AWS Lambda node process might be running from some other folder and it looks for readme.txt file from that folder as you have provided relative path, solution is to use absolute path.

This is an oldish question but comes up first when attempting to sort out whats going on with file paths on Lambda.

Additional Steps for Serverless Framework

For anyone using Serverless framework to deploy (which probably uses webpack to build) you will also need to add the following to your webpack config file (just after target: node):

  // assume target: 'node', is here

  node: {
    __dirname: false,
  },

Without this piece using __dirname with Serverless will STILL not get you the desired absolute directory path.

What worked for me was the comment by Vadorrequest to use process.env.LAMBDA_TASK_ROOT. I wrote a function to get a template file in a /templates directory when I'm running it locally on my machine with __dirname or with the process.env.LAMBDA_TASK_ROOT variable when running on Lambda:

function loadTemplateFile(templateName) {
  const fileName = `./templates/${templateName}`
  let resolved
  if (process.env.LAMBDA_TASK_ROOT) {
    resolved = path.resolve(process.env.LAMBDA_TASK_ROOT, fileName)
  } else {
    resolved = path.resolve(__dirname, fileName)
  }
  console.log(`Loading template at: ${resolved}`)
  try {
    const data = fs.readFileSync(resolved, 'utf8')
    return data
  } catch (error) {
    const message = `Could not load template at: ${resolved}, error: ${JSON.stringify(error, null, 2)}`
    console.error(message)
    throw new Error(message)
  }
}