[@aws-cdk/aws-lambda-nodejs] 'Cannot find entry file' when using a JSII construct that includes a lambda_nodejs.NodejsFunction

I’m trying to create a reusable library to handle ECR image scan results. The code is available at https://github.com/markusl/cdk-ecr-image-scan-handler

After publishing the generated library (using projen & JSII tools) to NPM and using it from another AWS CDK project I get the following, not very useful error message:

$ npm run build && cdk synth

> aws-cdk-pipelines-test@0.1.0 build aws-cdk-pipelines-test
> tsc

Cannot find entry file.
Subprocess exited with error 1

The directory structure of the imported NPM package under node_modules looks ok to me:

cdk-ecr-image-scan-handler/lib/index.js
cdk-ecr-image-scan-handler/lib/index.d.ts
cdk-ecr-image-scan-handler/lib/index.handler.js
cdk-ecr-image-scan-handler/lib/index.handler.d.ts

@jogold already provided some input for the source module setup which apparently is supposed to work like this:

new lambda_nodejs.NodejsFunction(this, 'handler', {
      runtime: lambda.Runtime.NODEJS_12_X,
      minify: true,
      role: lambdaRole,
      functionName: componentName,
      description: 'Handler for ECR Image Scan results',
      environment: {
        FROM_ADDRESS: props.fromAddress,
        TO_ADDRESS: props.toAddress,
      },
    });

Please let me know if there are any configuration errors in the project. I was looking for a reference setup but did not find one yet.

What did you expect to happen?

I would expect the Lambda function to be packaged correctly.

What actually happened?

I received the error.

Environment

• CLI Version : 1.59.0
• Framework Version: 1.59.0
• Node.js Version: v12.14.1
• OS : macOS
• Language (Version):

Other

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This is 🐛 Bug Report

[markusl]

@jogold we are also considering creating some internal libraries/tooling which require the bunding functionality. If we get this working 😃 I’d like to start with a simple example first to get the baseline configuration working.

Would you be able to provide a complete JSII module with an example setup using NodejsFunction bundling? That would be a good starting point for us and others as well.

[jogold]

@markusl switching to local bundling in your repo (https://github.com/markusl/cdk-ecr-image-scan-handler/pull/28, https://github.com/markusl/cdk-ecr-image-scan-handler/pull/29) made it work in your GitHub action.

It looks like Docker-in-Docker with volume mounts inside a GitHub action is problematic but we now have local bundling.

Regarding the Cannot find entry file I think we can improve the automatic entry finding in the CDK. There’s something to do with the source map.