(aws_lambda ): DockerImageFunction.fromImageAsset fails to include image assets

Describe the bug

In a construct library repo, if you create a lambda function using DockerImageFunction.fromImageAsset and then run npm run build, neither the Dockerfile nor the lambda function code is included in the packaged lib directory.

If you then import and use this construct in a different repo, you get a file not found error as the Dockerfile and lambda function code is not present in the build directory (lib) of the construct library.

The error is:

Error: Cannot find image directory at /Path/to/my/repo/lib/function

Expected Behavior

When running npm run build (or in my case npx projen build) the Dockerfile and Python files should be included in the “compiled” lib directory.

Current Behavior

The image assets are not included in the “compiled” lib directory and so when trying to use the construct in a stack results in a file-not-found error.

Reproduction Steps

In my construct library repository I define a lambda function construct and reference a local directory containing the assets for the lambda function.

.
├── MyLambda.ts
└── function
    ├── Dockerfile
    ├── README.md
    ├── WorkerFunction.py
    └── requirements.txt

where in MyLambda.ts the lambda function is defined like this:

    const workerFunction = new lambda.DockerImageFunction(this, 'worker-function', {
      functionName: 'lambda_handler',
      code: lambda.DockerImageCode.fromImageAsset(path.join(__dirname, 'function'),
        {
          cmd: ['WorkerFunction.lambda_handler'],
          entrypoint: ['/lambda-entrypoint.sh'],
        }),
      memorySize: 128,
      role: assumeFunctionRole,
      timeout: Duration.seconds(60),
    });

However if you then run npm run build on this construct library, the following gets built into the lib directory and we can see that the Dockerfile, python code, requirements.txt, and README.md are all missing.

    ├── MyLambda.d.ts
    └── MyLambda.js

Then you can attempt to use this construct in a different CDK project by linking them using npm:

cd ../my-other-repo
npm link ../my-construct-repo

Then if you attempt to reference the MyLambda construct and run cdk synth myLambdaStack you get a file-not-found error:

Error: Cannot find image directory at /Path/to/my/repo/lib/function

Possible Solution

A possible solution that I haven’t tried yet is separately defining the image separately using ecr assets and then referencing ECR repo image/tag in the Lambda function construct using the DockerImageFunction.fromEcr method.

Additional Information/Context

No response

CDK CLI Version

2.50.0 (build 4c11af6)

Framework Version

No response

Node.js Version

v16.14.0

OS

MacOS Catalina 10.15.7

Language

Typescript

Language Version

TypeScript (4.8.4)

Other information

No response

[pahud]

@mvs5465 I am not very sure but AFAIK projen would compile and copy typescript files under src to lib and leave everything outsides of src untouched. I would prefer having the lambda directories out of src like this

.
├── LICENSE
├── README.md
├── cdk.context.json
├── lambda
│   └── index.py
├── package.json
├── src
│   └── main.ts
├── test
│   └── main.test.ts
├── tsconfig.dev.json
└── yarn.lock

And have your lambda function code assets path point to the upper lambda directory like:

code: lambda.DockerImageCode.fromImageAsset(path.join(__dirname, '../lambda'),

I hope this would be helpful but definitely worth a ticket in https://github.com/projen/projen/issues to bring their attention for recommended practice. As this issue is not related to AWS CDK I am closing it for now but feel free to reopen it if you think it is still relevant to AWS CDK.

[github-actions[bot]]

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