AWS Lambda container on Docker template

app.py

def handler(event, context):
  return 'Hello from AWS Lambda using Python!'

docker-compose.yaml

version: "3.6"

services:
  lambda:
    container_name: lambda
    build: .
    volumes:
      - $HOME/.aws/:/root/.aws/
    ports:
      - "9000:8080"
    env_file:
      - .env.local

Dockerfile

FROM public.ecr.aws/lambda/python:3.9

# Copy function code
COPY app.py ${LAMBDA_TASK_ROOT}

# Install the function's dependencies using file requirements.txt
# from your project folder.

COPY requirements.txt  .
RUN  pip3 install -r requirements.txt --target "${LAMBDA_TASK_ROOT}"

# Set the CMD to your handler (could also be done as a parameter override outside of the Dockerfile)
CMD [ "app.handler" ]

requirements.txt

# some additional libraries

c.f. https://docs.aws.amazon.com/ja_jp/lambda/latest/dg/python-image.html