Local CDK Lambda Layer asset path not respected

[abrooksv]

Description

When using CDK to create a layer, SAM local does not respect the aws:asset:path metadata.

Steps to reproduce

Generated template snippet:

      "Type": "AWS::Lambda::LayerVersion",
      "Properties": {
        "Content": {
          "S3Bucket": {
            "Ref": "LayerCodeS3Bucket01B5996C"
          },
          "S3Key": {
            "Fn::Join": [
              "",
              [
                {
                  "Fn::Select": [
                    0,
                    {
                      "Fn::Split": [
                        "||",
                        {
                          "Ref": "LayerCodeS3VersionKey1E2A5824"
                        }
                      ]
                    }
                  ]
                },
                {
                  "Fn::Select": [
                    1,
                    {
                      "Fn::Split": [
                        "||",
                        {
                          "Ref": "LayerCodeS3VersionKey1E2A5824"
                        }
                      ]
                    }
                  ]
                }
              ]
            ]
          }
        }
      },
      "Metadata": {
        "aws:cdk:path": "Stack/Layer/Resource",
        "aws:asset:path": "/tmp/aws-lambda-layer-kubectl/layer.zip",
        "aws:asset:property": "Code"
      }
    },

Modified lambda_downloader.py to add logging:

        if layer.is_defined_within_template:
            LOG.info("%s is a local Layer in the template", layer.name)
            LOG.info("HELLO %s", layer.codeuri)
            layer.codeuri = resolve_code_path(self.cwd, layer.codeuri)
            LOG.info("FUN %s", layer.codeuri)
            return layer

Observed result

Logs:

[sam] Layer129049A2 is a local Layer in the template
[sam] HELLO .
[sam] FUN /Users/..../dist/cdk
[sam] Image was not found.
[sam] Building image...

Expected result

HELLO should say /tmp/aws-lambda-layer-kubectl/layer.zip

Additional environment details (Ex: Windows, Mac, Amazon Linux etc)

1. OS: OS X
2. sam --version: 0.21.0

Add --debug flag to command you are running

[jfuss]

@abrooksv Looks like a CDK bug. A Layer does not have a property 'Code', it should be 'Content'. LayerVersion docs: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-lambda-layerversion.html

[abrooksv]

Overwrote the template:

      "Metadata": {
        "aws:cdk:path": "Stack/Layer/Resource",
        "aws:asset:path": "/tmp/aws-lambda-layer-kubectl/layer.zip",
        "aws:asset:property": "Content"
      }

Leads to:

HELLO /tmp/aws-lambda-layer-kubectl/layer.zip
Resolving code path. Cwd=/Users/.../dist/cdk, CodeUri=/tmp/aws-lambda-layer-kubectl/layer.zip
FUN /tmp/aws-lambda-layer-kubectl/layer.zip

[jfuss]

CDK has the 'aws:asset:property` set incorrectly.

As far as the second issue (not allowing zip), we have an open issue for that here #947 but really the path should be pointed to the source (none-zipped asset).

Closing as an issue is open with CDK and we already have an tracking issue for the other issue brought up.