Unable to load module due to `finalhandler` dependency

This is a Bug Report

Description

• What went wrong? Express-based web app won’t run on AWS, but it works locally using the serverless-offline plugin.

• What did you expect should have happened? Expected to run with no errors on AWS Lambda environment.

• What was the config you used?

Here’s the serverless.yml:

service: testing-app

plugins:
  - serverless-offline

provider:
  name: aws
  runtime: nodejs6.10
  stage: dev
  region: us-west-2

functions:
  app:
    handler: server.handler
    events:
      - http: ANY /
      - http: 'ANY {proxy+}'

Here’s package.json:

{
  "name": "testing",
  "version": "1.0.0",
  "private": true,
  "main": "server.js",
  "dependencies": {
    "async": "^2.6.0",
    "bcrypt-nodejs": "0.0.3",
    "body-parser": "^1.13.1",
    "capitalize": "^1.0.0",
    "connect-flash": "^0.1.1",
    "cookie-parser": "^1.3.5",
    "dateformat": "^3.0.2",
    "ejs": "^2.3.2",
    "express": "^4.16.2",
    "express-csv": "^0.6.0",
    "express-session": "^1.11.3",
    "format-currency": "^1.0.0",
    "formidable": "^1.1.1",
    "moment": "^2.19.2",
    "morgan": "^1.6.0",
    "mysql": "^2.7.0",
    "nodemailer": "^4.4.0",
    "passport": "^0.2.2",
    "passport-local": "^1.0.0",
    "phantom-html-to-pdf": "^0.5.5",
    "serverless-http": "^1.5.2",
    "slugify": "^1.2.4"
  },
  "devDependencies": {
    "serverless-offline": "^3.16.0"
  }
}

• What stacktrace or error message from your provider did you see?

Here’s the Lambda function logs:

START RequestId: 03466ae4-d11e-11e7-9f97-2f79ff0bb01d Version: $LATEST
Unable to import module 'server': Error
at Function.Module._resolveFilename (module.js:469:15)
at Function.Module._load (module.js:417:25)
at Module.require (module.js:497:17)
at require (internal/module.js:20:19)
at Object.<anonymous> (/var/task/node_modules/finalhandler/index.js:14:29)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
END RequestId: 03466ae4-d11e-11e7-9f97-2f79ff0bb01d
REPORT RequestId: 03466ae4-d11e-11e7-9f97-2f79ff0bb01d	Duration: 6.27 ms	Billed Duration: 100 ms Memory Size: 1024 MB	Max Memory Used: 22 MB	

For feature proposals:

Similar or dependent issues:

Additional Data

The issues seems to be related to the fact that it can’t load finalhandler. I checked the package generated by serverless and the module is present under node_modules.

Found this: https://github.com/pillarjs/finalhandler/issues/19 , but it doesn’t help.

• Serverless Framework Version you’re using:

serverless -v
1.18.0

• Operating System: MacOS 10.12.6

• Stack Trace:

• Provider Error messages:

[seeden]

I have same error with latest serverless.

[dschep]

I’m not sure why sls offline is working… but you say you’re using express but I don’t see serverless-http in your plugins, so I wouldn’t expect it to work.