DeployLambda.js

"use strict";

let aws = require('aws-sdk'),
  fs = require('fs'),
  q = require('q'),
  s3 = new aws.S3({signatureVersion: 'v4'}),
  Logger = require('pretty-logger'),
  log = new Logger(),
  lambda = new aws.Lambda({region: 'us-east-1'});

function putObject(params) {
  let defer = q.defer();
  s3.putObject(params, (err, data) => {
    if (err) defer.reject(err);
    else defer.resolve(data);
  });
  return defer.promise;
}

function updateFunctionCode(params) {
  let defer = q.defer();
  lambda.updateFunctionCode(params, (err, data) => {
    if (err) defer.reject(err);
    else defer.resolve(data);
  });
  return defer.promise;
}

(function updateLambda(zipfile, funcName) {
  if (!zipfile || !funcName) {
    log.error('Specify filename to upload and function name to publish');
    process.exit(1);
  }

  putObject({
    Bucket: 'bucket-name',
    Key: `sub/directory/${zipfile}`,
    Body: fs.readFileSync(zipfile)
  })
    .then(() => {
      log.info(`Successfully uploaded file: ${zipfile}`);
      return updateFunctionCode({
        FunctionName: funcName,
        S3Bucket: 'johni',
        S3Key: `twitter-trends/lambda/${zipfile}`,
        Publish: false
      })
    })
    .then(log.info.bind(log))
    .catch(log.error.bind(log))
    .finally(() => {
      process.exit();
    });
})(process.argv[2], process.argv[3]);