Runtime.ImportModuleError: Unable to import module '': No module named ''

[nataliemona]

Following Python 3.9 Alpine Linux instructions from:
https://aws.amazon.com/blogs/aws/new-for-aws-lambda-container-image-support/

The only line I changed in the Dockerfile is:
COPY app/* ${FUNCTION_DIR} to COPY app.py ${FUNCTION_DIR}

# Define global args
ARG FUNCTION_DIR="/home/app/"
ARG RUNTIME_VERSION="3.9"
ARG DISTRO_VERSION="3.12"

# Stage 1 - bundle base image + runtime
# Grab a fresh copy of the image and install GCC
FROM python:${RUNTIME_VERSION}-alpine${DISTRO_VERSION} AS python-alpine
# Install GCC (Alpine uses musl but we compile and link dependencies with GCC)
RUN apk add --no-cache \
    libstdc++

# Stage 2 - build function and dependencies
FROM python-alpine AS build-image
# Install aws-lambda-cpp build dependencies
RUN apk add --no-cache \
    build-base \
    libtool \
    autoconf \
    automake \
    libexecinfo-dev \
    make \
    cmake \
    libcurl
# Include global args in this stage of the build
ARG FUNCTION_DIR
ARG RUNTIME_VERSION
# Create function directory
RUN mkdir -p ${FUNCTION_DIR}
# Copy handler function
COPY app.py ${FUNCTION_DIR}
# Optional – Install the function's dependencies
# RUN python${RUNTIME_VERSION} -m pip install -r requirements.txt --target ${FUNCTION_DIR}
# Install Lambda Runtime Interface Client for Python
RUN python${RUNTIME_VERSION} -m pip install awslambdaric --target ${FUNCTION_DIR}

# Stage 3 - final runtime image
# Grab a fresh copy of the Python image
FROM python-alpine
# Include global arg in this stage of the build
ARG FUNCTION_DIR
# Set working directory to function root directory
WORKDIR ${FUNCTION_DIR}
# Copy in the built dependencies
COPY --from=build-image ${FUNCTION_DIR} ${FUNCTION_DIR}
# (Optional) Add Lambda Runtime Interface Emulator and use a script in the ENTRYPOINT for simpler local runs
ADD https://github.com/aws/aws-lambda-runtime-interface-emulator/releases/latest/download/aws-lambda-rie /usr/bin/aws-lambda-rie
COPY entry.sh /
RUN chmod 755 /usr/bin/aws-lambda-rie /entry.sh
ENTRYPOINT [ "/entry.sh" ]
CMD [ "app.handler" ]

app.py

import json


def handler(event, context):
    body = {
        "message": "Go Serverless v1.0! Your function executed successfully!",
        "input": event,
    }
    response = {
        "statusCode": 200,
        "body": json.dumps(body),
    }
    return response

entry.sh

#!/bin/sh
if [ -z "${AWS_LAMBDA_RUNTIME_API}" ]; then
    exec /usr/bin/aws-lambda-rie /usr/local/bin/python -m awslambdaric $1
else
    exec /usr/local/bin/python -m awslambdaric $1
fi

Running: curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{"payload": "hello world!"}'
Getting the error: {"errorMessage": "Unable to import module '': No module named ''", "errorType": "Runtime.ImportModuleError"}

This is hard to debug because the module is an empty string.

I am able to connect to the docker container with docker exec -it <name> /bin/sh and then run the handler directly with python -c 'import app; print(app.handler({}, {}))'. The handler runs with no errors if I run it directly.

[matthewchung74]

you might want to try something like this.

import json
import traceback

def respond(err, res=None):
    return {
        "statusCode": "400" if err else "200",
        "body": err["message"] if err else json.dumps(res),
        "headers": {"Content-Type": "application/json"},
    }

def lambda_handler(event, context): 
    try:
        import sys
        # from lib.inference import predict
    except Exception as e:
        error = str(e)
        stacktrace = json.dumps(traceback.format_exc())
        message = "Exception: " + error + "  Stacktrace: " + stacktrace
        err = {"message": message}
        return respond(err)

    return respond(None, "wow25520003")

i can't find the original link I got it from, but it will catch import errors.

[maxday]

Thanks for reaching out, since there is no activity on this issue, I'll close it for now, let us know if you still facing the issue or if you feel that it should not have been closed. Thanks!