Unable to Load Gems from Lambda Layer in Lambda Function Using Single Dockerfile

I'm facing an issue while attempting to load gems from a Lambda layer within a Lambda function, both defined in a single Dockerfile. Here's my current setup and the problem I'm encountering:

Current Setup:I'm using Docker to build a container image for an AWS Lambda function. In the Dockerfile, I define both the Lambda layer, containing necessary gems, and the Lambda function code.

Problem:Even though I've successfully built the Docker image, the Lambda function fails to load gems from the Lambda layer. Specifically, I'm trying to load the faraday gem within the Lambda function, but it's throwing a "cannot load such file" error.

My current file structure is as follows:

• Gemfile
• Gemfile.lock
• Dockerfile
• lambda_function.rb

Here's my Dockerfile:

# Lambda LayerFROM alpine:latest as layer-builderRUN apk add --no-cache ruby ruby-bundler ruby-devRUN mkdir -p /opt/COPY Gemfile Gemfile.lock ./RUN gem install bundler:2.4.22RUN bundle config set --local path /opt/RUN bundle install# Lambda FunctionFROM public.ecr.aws/lambda/ruby:3.2WORKDIR ${LAMBDA_TASK_ROOT}COPY --from=layer-builder /opt/ /opt/COPY Gemfile ${LAMBDA_TASK_ROOT}/COPY Gemfile.lock ${LAMBDA_TASK_ROOT}/COPY lambda_function.rb ${LAMBDA_TASK_ROOT}/RUN echo $(ls /opt/ruby/3.2.0/gems/) # installed gems existCMD [ "lambda_function.LambdaFunction::Handler.process" ]

Here's my Lambda function file:

puts ENV['GEM_PATH'] # /opt/ruby/3.2.0/gems/require 'faraday' # cannot load such file -- faradaymodule LambdaFunction  class Handler    def self.process(event:,context:)      ...    end  endend

Additional Details:

• Steps to Reproduce:

1. Build the Docker image: docker build -t lambda-function:latest . --no-cache
2. Run the Docker container: docker run --rm -p 9000:8080 lambda-function:latest
3. Send a request to the Lambda function: curl 'http://localhost:9000/2015-03-31/functions/function/invocations'

I suspect there might be an issue with how I'm defining the layers or copying files between them. Any insights or suggestions on how to ensure that gems from the Lambda layer are properly loaded within the Lambda function would be greatly appreciated.