Sam local Invoke lambda with local layer error

Description:

When invoking a function locally, which relies on a layer built locally as well, the function cannot find the module which is part of the layer. When uploading that layer through the AWS console, and changing the Layer’s reference in the template.yaml file, the import works. The layer is 17Mb zipped, and contains the mysql-connector-python module, as well as the requests module.

Steps to reproduce the issue:

1. Have a larger than 10MB layer (maybe more, just took the recommended max size from AWS console)
2. Import layer’s package and run sam local invoke FunctionName
3. Deploy the layer manually in AWS console
4. Run sam local invoke FunctionName again after changing the lambda’s layers property to the remote ARN in template.yaml.

Observed result:

Failure when calling Layer locally:

Expected result:

Calling layer locally or from remote have the same output.

[jfuss]

@Cecarlego We support layers that are local as well, just not ones that are already zipped. The value of Content or ContentUri (depending on the resource you are using for Layers), should be the directory to where the code is and be unzipped. If that is true, then we will pick up that layer, combine it with any other layers for the function and make it available in the container.

[jfuss]

@indyfin DO NOT do that. The vendored requests library is old and not updated, see https://github.com/boto/botocore/issues/1745#issuecomment-497833200 and https://github.com/boto/botocore/issues/1608