Lambda can't find NodeJS layer packages during compilation

[hiren-quovantis]

• Expected behavior: I ran the Claudia update command with --layers tag for deployment purposes. The layer contains the common node js packages, as defined here: https://docs.aws.amazon.com/lambda/latest/dg/configuration-layers.html#configuration-layers-path

I am referring to one of the dependencies ('mssql' included in the layer) from my index js file.

• What actually happens: I get the following error: validating package Error: Cannot find module 'mssql' at Function.Module._resolveFilename (internal/modules/cjs/loader.js:580:15) at Function.Module._load (internal/modules/cjs/loader.js:506:25) at Module.require (internal/modules/cjs/loader.js:636:17) at require (internal/modules/cjs/helpers.js:20:18)

• Steps to reproduce the problem:

1. Simply create a nodejs layer as described here: https://docs.aws.amazon.com/lambda/latest/dg/configuration-layers.html#configuration-layers-path and Deploy it
2. Create a new lambda (index.js file) and refer to any of the packages installed in Nodejs layer.
3. Try deploying the lambda using Claudia create or Claudia update command

[gojko]

if this fails during claudia packaging, there are two options:

1) install mysql as an optional dependency , then use --no-optional-dependencies when you deploy with claudia. it will not bundle the dependency in the package, but it will pass validation 2) lazy-load the required package (not in the file headers, but in a function on first use) to use layer dependencies that are not bundled with your code. alternatively, you can