AWS Lambda Recursive HTTP File Upload using NodeJS

lambda-function.js

const aws = require('aws-sdk');
const { writeFileSync, statSync, createReadStream } = require('fs');
const fetch = require('node-fetch');
const FormData = require('form-data');

exports.handler = async (event, context) => {
  const { numberOfCalls = 0, url } = event;

  const lambda = new aws.Lambda();

  /* if numberOfCalls still has value, continue recursive operation */
  if (numberOfCalls > 0) {
    const now = Date.now();
    // File should be added on `/tmp` folder
    const filename = `/tmp/test-${now}.txt`;

    console.log(`[INFO] Adding file '${filename}' in call number '${numberOfCalls}'`);

    const content = new Array(20)
      .fill(null)
      .map((_) => 'This is line ' + `${now}`.repeat(10000) + '\r\n');

    writeFileSync(filename, content);

    const form = new FormData();
    const { size: fileSizeInBytes } = statSync(filename);
    const fileStream = createReadStream(filename, 'utf8');
    form.append('file', fileStream, { knownLength: fileSizeInBytes });

    const response = await fetch(`${url}/<your-api-endpoint>`, {
      method: 'POST',
      headers: {
        Accept: 'application/json',
      },
      body: form,
    });

    console.log(`[INFO] Response: ${response.status} ${response.statusText}`);

    const params = {
      FunctionName: context.functionName,
      InvocationType: 'Event',
      Payload: JSON.stringify({ ...event, numberOfCalls: numberOfCalls - 1 }),
      Qualifier: context.functionVersion,
    };

    return new Promise((resolve, reject) => {
      console.log(`[INFO] invoking lambda with params ${params}`);
      lambda.invoke(params, (err, data) => (err ? reject(err) : resolve(data)));
    });
  } else {
    console.log('[INFO] recursive call finished');
    context.succeed('finished');
  }
};

package.json

{
  "name": "nodejs",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node index.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "aws-sdk": "^2.782.0",
    "form-data": "^3.0.0",
    "node-fetch": "^2.6.1"
  }
}