Cannot find module 'jsonwebtoken' error when importing dependency from AWS Lambda Layer

Question

Good day! I am testing an AWS Lambda Function that uses an AWS Lambda Layer with the following directory:

LambdaLayer.zip
  nodejs/
    package.json
    package-lock.json
    node_modules/
      jsonwebtoken/

In my Lambda Function (running on node 14.x runtime), I am importing the module from the layer like this:

const jwt = require('jsonwebtoken');

However, I am getting the following error:

ERROR   Uncaught Exception {"errorType":"Runtime.ImportModuleError","errorMessage":"Error: Cannot find module 'jsonwebtoken'\nRequire stack:\n- /var/task/index.js\n- /var/runtime/UserFunction.js\n- /var/runtime/index.js","stack":["Runtime.ImportModuleError: Error: Cannot find module 'jsonwebtoken'","Require stack:","- /var/task/index.js","- /var/runtime/UserFunction.js","- /var/runtime/index.js","

I already followed the directory structure as per AWS documentation and as also stated here: AWS lambda layers error when call API "cannot find module". Still, I'm getting this error.

I also tried the below directory structure but still did not work:

LambdaLayer.zip
  nodejs/
    node14/
      node_modules/
        jsonwebtoken/

Am I missing something?

P.S. I have compressed the directory using zip -r LambdaLayer.zip LambdaLayer/ and also uploaded it to Lambda layer manually via the AWS Console.

Mike_B Mike_B · Accepted Answer · 2021-09-11T02:14:08

I already found the root cause of the issue. What I was actually doing is that I'm zipping the LambdaLayer folder as the top-level directory instead of nodejs.

What I thought I was doing:

LambdaLayer.zip
  nodejs/
    node_modules/
      jsonwebtoken/

What I am actually doing:

LambdaLayer.zip
  LambdaLayer/
    nodejs/
      node_modules/
        jsonwebtoken/

This is why the function cannot find the module. After zipping the nodejs folder instead of the LambdaLayer, it now worked.

Cannot find module 'jsonwebtoken' error when importing dependency from AWS Lambda Layer

1 Answers