AWS Lambda Application Layer

Question

I'm trying to create a layer from an AWS Lambda Application and reference that layer from another AWS Lambda Application.

I have the first application creating the layer.

Application template.yml

index.js for layer

Layer in AWS Console

Zip of the layer

When I reference the layer from my other application I get the following build error.

template.yml for other application

I am able to add the layer to the lambda through the aws console.

What's the correct way to reference this layer from the template.yml?

Update - debug output

sam local start-lambda --debug 2021-12-16 21:39:37,696 | Telemetry endpoint configured to be https://aws-serverless-tools-telemetry.us-west-2.amazonaws.com/metrics 2021-12-16 21:39:37,696 | Using config file: samconfig.toml, config environment: default 2021-12-16 21:39:37,696 | Expand command line arguments to: 2021-12-16 21:39:37,696 | --template_file=C:\Users\bensi\IdeaProjects\tu-record\template.yml --host=127.0.0.1 --port=3001 --layer_cache_basedir=C:\Users\bensi\ AppData\Roaming\AWS SAM\layers-pkg --container_host=localhost --container_host_interface=127.0.0.1 2021-12-16 21:39:37,949 | local start_lambda command is called 2021-12-16 21:39:37,955 | Collected default values for parameters: {} 2021-12-16 21:39:37 Plugin 'ServerlessAppPlugin' raised an exception: 'list' object has no attribute 'get' Traceback (most recent call last):
File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\plugins_init_.py", line 133, in act getattr(plugin, method_name)(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\metrics\method_decorator.py", line 96, in wrapper_cw_timer exec_result = func(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\plugins\application\serverless_app_plugin.py", line 92, in on_before_transfor m_template for logical_id, app in template.iterate({SamResourceType.Application.value}): File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\sdk\template.py", line 33, in iterate resource = SamResource(resource_dict) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\sdk\resource.py", line 24, in init self.type = resource_dict.get("Type") AttributeError: 'list' object has no attribute 'get' 2021-12-16 21:39:37,973 | Sending Telemetry: {'metrics': [{'commandRun': {'requestId': 'd4aa74c5-a627-407e-8f65-f86fa97eeb15', 'installationId': 'e4cd6d85-622f -47df-8c87-08d5d6c395d6', 'sessionId': '80147f0f-42ce-4539-9edd-f08dd86eebcf', 'executionEnvironment': 'CLI', 'ci': False, 'pyversion': '3.8.8', 'samcliVersion ': '1.36.0', 'awsProfileProvided': False, 'debugFlagProvided': True, 'region': '', 'commandName': 'sam local start-lambda', 'duration': 277, 'exitReason': 'Att ributeError', 'exitCode': 255}}]} 2021-12-16 21:39:38,176 | Telemetry response: 200 Traceback (most recent call last): File "runpy.py", line 194, in _run_module_as_main File "runpy.py", line 87, in run_code File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli_main.py", line 12, in cli(prog_name="sam") File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 829, in call return self.main(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 782, in main rv = self.invoke(ctx) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 1259, in invoke return _process_result(sub_ctx.command.invoke(sub_ctx)) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 1259, in invoke return process_result(sub_ctx.command.invoke(sub_ctx)) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 1066, in invoke return ctx.invoke(self.callback, **ctx.params) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 610, in invoke return callback(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\decorators.py", line 73, in new_func return ctx.invoke(f, obj, *args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\click\core.py", line 610, in invoke return callback(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli\lib\telemetry\metric.py", line 157, in wrapped raise exception # pylint: disable=raising-bad-type File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli\lib\telemetry\metric.py", line 122, in wrapped File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli\lib\providers\sam_stack_provider.py", line 51, in init self.template_dict = self.get_template( File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli\lib\providers\sam_base_provider.py", line 189, in get_template template_dict = SamTranslatorWrapper(template_dict, parameter_values=parameters_values).run_plugins() File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli\lib\samlib\wrapper.py", line 68, in run_plugins parser.parse(template_copy, all_plugins) # parse() will run all configured plugins File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samcli\lib\samlib\wrapper.py", line 88, in parse sam_plugins.act(LifeCycleEvents.before_transform_template, sam_template) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\plugins_init.py", line 139, in act raise ex File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\plugins_init.py", line 133, in act getattr(plugin, method_name)(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\metrics\method_decorator.py", line 96, in wrapper_cw_timer exec_result = func(*args, **kwargs) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\plugins\application\serverless_app_plugin.py", line 92, in on_before_transfor m_template for logical_id, app in template.iterate({SamResourceType.Application.value}): File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\sdk\template.py", line 33, in iterate resource = SamResource(resource_dict) File "C:\Program Files\Amazon\AWSSAMCLI\runtime\lib\site-packages\samtranslator\sdk\resource.py", line 24, in init self.type = resource_dict.get("Type") AttributeError: 'list' object has no attribute 'get'

Answer 1

If you have the custom layer and the lambda function in different SAM templates, try this approach:

Resources:
   MyCustomLayer:
        Type: AWS::Serverless::LayerVersion
        Properties:
            LayerName: my-test-layer
            Description: 
            ContentUri: src
            CompatibleRuntimes:
              - nodejs14.x
            RetentionPolicy: Retain
        Metadata:
             BuildMethod: nodejs14.x

Outputs:
  MyCustomLayer:
    Description: "Shared layer"
    Value: !Ref MyCustomLayer
    Export:
      Name: !Sub MyCustomLayer

Use the Layer reference in the Lambda in the second template:

Layers:
    - Fn::ImportValue:
       !Sub MyCustomLayer

If you have both the layer & lambda in the same stack, then simply use the !Ref to dynamically use ARN instead of hardcoding the version

Layers:
 - !Ref LayerNameInSAMTemplate

Answer 2

I needed to move the Layers: config in the template.yml under the lambda resource and replace $LATEST with a hardcoded reference to the version.

Resources:
  record:
    Type: AWS::Serverless::Function
    Properties:
      Layers:
        - arn:aws:lambda:us-east-2:501480421890:layer:testing-layers:7

Answer 3

Layer in your application template is expecting list Dictionary but its getting list because of - that could be the reason.[need to do more analysis]

Meanwhile, I suggest you use the below method to include the layer in your application

MyLayer:
  Type: AWS::Lambda::LayerVersion
  Properties:
    CompatibleRuntimes:
      - nodejs12.x
    Content:
      S3Bucket: <your-bucket-name>
      S3Key: layer.zip
    Description: My layer
    LayerName: my-layer
    LicenseInfo: MIT