Serverless Offline undefined module when loaded from lambda layer - amazon-web-services

Question

I have the following project tree
Where nodejs folder is a lambda layer defined in the following serverless.yaml
service: aws-nodejs # NOTE: update this with your service name
provider:
name: aws
runtime: nodejs8.10
stage: dev
plugins:
- serverless-offline
layers:
layer1:
path: nodejs # required, path to layer contents on disk
name: ${self:provider.stage}-layerName # optional, Deployed Lambda layer name
functions:
hello:
handler: handler.hello
layers:
- {Ref: Layer1LambdaLayer}
events:
- http:
path: /dev
method: get
The layer1 only contains UUID package.
So when I try to run the lambda locally using serverless offline plugin, it says can't find module UUID.
But when I deploy the code to AWS, it run like a charm.
Any way we can get lambda layers running locally for testing purpose? and for speeding up the development?
Or is there any way where I can dynamically set the node_module path to point to the layer folder during the development and once I need to push to production, it change the path to the proper one

Answer 1

Ok after many trials, I figure out a working solution
I added a npm run command which export a temporary node_module path to the list of paths
"scripts": {
"offline": "export NODE_PATH=\"${PWD}/nodejs/node_modules\" && serverless offline"
},
So, node can lookup for the node modules inside the sub folders

Answer 2

I got around this by running serverless-offline in a container and copying my layers into the /opt/ directory with gulp. I set a gulp watch to monitor any layer changes and to copy them to the /opt/ directory.

Answer 3

I use layers in serverless offline via installing a layer from local file system as a dev dependency.
npm i <local_path_to_my_layer_package> --save-dev

Answer 4

BTW this issue was fixed in sls 1.49.0.
Just run:
sudo npm i serverless
Then you should specify package include in serverless.yml's layer section
service: aws-nodejs # NOTE: update this with your service name
provider:
name: aws
runtime: nodejs8.10
stage: dev
plugins:
- serverless-offline
layers:
layer1:
path: nodejs # required, path to layer contents on disk
package:
include:
- node_modules/**
name: ${self:provider.stage}-layerName # optional, Deployed Lambda layer name
functions:
hello:
handler: handler.hello
layers:
- {Ref: Layer1LambdaLayer}
events:
- http:
path: /dev
method: get
Tested on nodejs10.x runtime