aws-lambdaesmodulesnode-js-14

Cannot import package in AWS lambda with Nodejs14.x ES module

I have a layer where the path of node_modules is nodejs/node14/node_modules.

Using that layer, and I try to import a package in a Lambda function, say 'aws-cloudfront-sign', like this:

import cfsign from 'aws-cloudfront-sign'

I got error message

Cannot find package 'aws-cloudfront-sign' imported from /var/task/signer.js\nDid you mean to import aws-cloudfront-sign/lib/cloudfrontUtil.js?

But if I import the package like this:

import cfsign from '/opt/nodejs/node14/node_modules/aws-cloudfront-sign/lib/cloudfrontUtil.js'

It succeeds.

Do you know why? How could I import the package correctly?

Solution

  • 2023 Update:

    Note that the solution below was for a Node 14 problem with a specific SDK version, per the question. Imports for AWS SDK v3 are now supported in Node 18+. Using the below solution for other Node/SDK versions likely will not work.

    See the AWS post here and the discussion ESM imports from NODE_PATH are not available when using Lambda's Node Runtime 14 and 16.

    End update

    This appears to be a bug. It is occurring with layers and the SDK. There are are a number of similar open issues on Github:

    Nodejs Lambda: Cannot find package 'aws-sdk'

    Cannot find package when using ES Module and Lambda Layer

    ES6 imports don't work in @aws-sdk/client-iotsitewise

    As you have worked out, the only workaround at present seems to be the use of absolute paths. E.g.:

    import { DynamoDB } from 'aws-sdk;'

    fails, whereas

    import AWS from '/var/runtime/node_modules/aws-sdk/lib/aws.js';
const { DynamoDB } = AWS;

    will work.

    I suggest you add your voice to an existing open issue to help ensure it gets attention.