node_module errors with AWS lambda, what's the best practice for dependencies?

Question

I've been trying to convert and deploy one of our node.js apps into a lambda function and have been having some problems with the node_modules dependencies - saying that it can't find certain modules. I started by creating a package.json, npm install the dependencies locally then copy the node modules folder up to lambda.

For instance I have a project that requires sequelize and convict and have been getting errors saying that it cannot find the moment module as a sub-dependency. I see that moment is included in the root of my node_modules but it was not included in the sub folder under the sequelize module.

However, this project runs fine locally. What is the difference in lambda and what's the best practice for deploying a somewhat long list of node modules with it - just a copy of the node_modules folder? On some of the other simpler projects I have, the small amount of node_modules can be copied up with no problems.

{
  "errorMessage": "Cannot find module 'moment'",
  "errorType": "Error",
  "stackTrace": [
    "Function.Module._resolveFilename (module.js:338:15)",
    "Function.Module._load (module.js:280:25)",
    "Module.require (module.js:364:17)",
    "require (module.js:380:17)",
    "VERSION (/var/task/node_modules/sequelize/node_modules/moment-timezone/moment-timezone.js:14:28)",
    "Object. (/var/task/node_modules/sequelize/node_modules/moment-timezone/moment-timezone.js:18:2)",
    "Module._compile (module.js:456:26)",
    "Object.Module._extensions..js (module.js:474:10)",
    "Module.load (module.js:356:32)",
    "Function.Module._load (module.js:312:12)"
  ]
}

Oswaldo Zapata Oswaldo Zapata · Accepted Answer · 2018-05-29T16:35:59

I resolved this by uploading all from a zip file which contains all the data I need for my lambda function.

you can just create your project in your local machine and make all the changes that you need then the file you are going to zip should have this same structure and also see that there is an option to load your code from a zip file.

node_module errors with AWS lambda, what's the best practice for dependencies?

2 Answers