## AWS Lambda Python Runtime Interface Client We have open-sourced a set of software packages, Runtime Interface Clients (RIC), that implement the Lambda [Runtime API](https://docs.aws.amazon.com/lambda/latest/dg/runtimes-api.html), allowing you to seamlessly extend your preferred base images to be Lambda compatible. The Lambda Runtime Interface Client is a lightweight interface that allows your runtime to receive requests from and send requests to the Lambda service. The Lambda Python Runtime Interface Client is vended through [pip](https://pypi.org/project/awslambdaric). You can include this package in your preferred base image to make that base image Lambda compatible. ## Requirements The Python Runtime Interface Client package currently supports Python versions: - 3.7.x up to and including 3.11.x ## Usage ### Creating a Docker Image for Lambda with the Runtime Interface Client First step is to choose the base image to be used. The supported Linux OS distributions are: - Amazon Linux 2 - Alpine - CentOS - Debian - Ubuntu Then, the Runtime Interface Client needs to be installed. We provide both wheel and source distribution. If the OS/pip version used does not support [manylinux2014](https://www.python.org/dev/peps/pep-0599/) wheels, you will also need to install the required build dependencies. Also, your Lambda function code needs to be copied into the image. ```dockerfile # Include global arg in this stage of the build ARG FUNCTION_DIR # Install aws-lambda-cpp build dependencies RUN apt-get update && \ apt-get install -y \ g++ \ make \ cmake \ unzip \ libcurl4-openssl-dev # Copy function code RUN mkdir -p ${FUNCTION_DIR} COPY app/* ${FUNCTION_DIR} # Install the function's dependencies RUN pip install \ --target ${FUNCTION_DIR} \ awslambdaric ``` The next step would be to set the `ENTRYPOINT` property of the Docker image to invoke the Runtime Interface Client and then set the `CMD` argument to specify the desired handler. Example Dockerfile (to keep the image light we use a multi-stage build): ```dockerfile # Define custom function directory ARG FUNCTION_DIR="/function" FROM public.ecr.aws/docker/library/python:buster as build-image # Include global arg in this stage of the build ARG FUNCTION_DIR # Install aws-lambda-cpp build dependencies RUN apt-get update && \ apt-get install -y \ g++ \ make \ cmake \ unzip \ libcurl4-openssl-dev # Copy function code RUN mkdir -p ${FUNCTION_DIR} COPY app/* ${FUNCTION_DIR} # Install the function's dependencies RUN pip install \ --target ${FUNCTION_DIR} \ awslambdaric FROM public.ecr.aws/docker/library/python:buster # 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} ENTRYPOINT [ "/usr/local/bin/python", "-m", "awslambdaric" ] CMD [ "app.handler" ] ``` Example Python handler `app.py`: ```python def handler(event, context): return "Hello World!" ``` ### Local Testing To make it easy to locally test Lambda functions packaged as container images we open-sourced a lightweight web-server, Lambda Runtime Interface Emulator (RIE), which allows your function packaged as a container image to accept HTTP requests. You can install the [AWS Lambda Runtime Interface Emulator](https://github.com/aws/aws-lambda-runtime-interface-emulator) on your local machine to test your function. Then when you run the image function, you set the entrypoint to be the emulator. *To install the emulator and test your Lambda function* 1) From your project directory, run the following command to download the RIE from GitHub and install it on your local machine. ```shell script mkdir -p ~/.aws-lambda-rie && \ curl -Lo ~/.aws-lambda-rie/aws-lambda-rie https://github.com/aws/aws-lambda-runtime-interface-emulator/releases/latest/download/aws-lambda-rie && \ chmod +x ~/.aws-lambda-rie/aws-lambda-rie ``` 2) Run your Lambda image function using the docker run command. ```shell script docker run -d -v ~/.aws-lambda-rie:/aws-lambda -p 9000:8080 \ --entrypoint /aws-lambda/aws-lambda-rie \ myfunction:latest \ /usr/local/bin/python -m awslambdaric app.handler ``` This runs the image as a container and starts up an endpoint locally at `http://localhost:9000/2015-03-31/functions/function/invocations`. 3) Post an event to the following endpoint using a curl command: ```shell script curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}' ``` This command invokes the function running in the container image and returns a response. *Alternately, you can also include RIE as a part of your base image. See the AWS documentation on how to [Build RIE into your base image](https://docs.aws.amazon.com/lambda/latest/dg/images-test.html#images-test-alternative).* ## Development ### Building the package Clone this repository and run: ```shell script make init make build ``` ### Running tests Make sure the project is built: ```shell script make init build ``` Then, * to run unit tests: `make test` * to run integration tests: `make test-integ` * to run smoke tests: `make test-smoke` ### Troubleshooting While running integration tests, you might encounter the Docker Hub rate limit error with the following body: ``` You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limits ``` To fix the above issue, consider authenticating to a Docker Hub account by setting the Docker Hub credentials as below CodeBuild environment variables. ```shell script DOCKERHUB_USERNAME= DOCKERHUB_PASSWORD= ``` Recommended way is to set the Docker Hub credentials in CodeBuild job by retrieving them from AWS Secrets Manager. ## Security If you discover a potential security issue in this project we ask that you notify AWS/Amazon Security via our [vulnerability reporting page](http://aws.amazon.com/security/vulnerability-reporting/). Please do **not** create a public github issue. ## License This project is licensed under the Apache-2.0 License.