Repository files navigation

The Lambda Runtime Interface Emulator is a proxy for Lambda’s Runtime and Extensions APIs, which allows customers tolocally test their Lambda function packaged as a container image. It is a lightweight web-server that convertsHTTP requests to JSON events and maintains functional parity with the Lambda Runtime API in the cloud. Itallows you to locally test your functions using familiar tools such as cURL and the Docker CLI (when testingfunctions packaged as container images). It also simplifies running your application on additional computes.You can include the Lambda Runtime Interface Emulator in your container image to have it accept HTTPrequests instead of the JSON events required for deployment to Lambda. This component does not emulateLambda’s orchestrator, or security and authentication configurations. You can get started by downloading and installing it on your local machine. When the Lambda Runtime API emulator is executed, a/2015-03-31/functions/function/invocations endpoint will be stood up within the container that you post data to it in order to invoke your function for testing.

• Installing
• Getting started
  • Test an image with RIE included in the image
    • To test your Lambda function with the emulator
  • Build RIE into your base image
    • To build the emulator into your image
  • Test an image without adding RIE to the image
    • To test an image without adding RIE to the image
• How to configure
• Level of support
• Security
• License

Instructions for installing AWS Lambda Runtime Interface Emulator for your platform

There are a few ways you use the Runtime Interface Emulator (RIE) to locally test your function depending on the base image used.

The AWS base images for Lambda include the runtime interface emulator. You can also follow these steps if you built the RIE into your alternative base image.

1. Build your image locally using the docker build command.

   docker build -t myfunction:latest .

2. Run your container image locally using the docker run command.

   docker run -p 9000:8080 myfunction:latest

   This command runs the image as a container and starts up an endpoint locally atlocalhost:9000/2015-03-31/functions/function/invocations.

3. Post an event to the following endpoint using a curl command:

   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.

You can build RIE into a base image. Download the RIE from GitHub to your local machine and update your Dockerfile to install RIE.

1. Create a script and save it in your project directory. Set execution permissions for the script file.

   The script checks for the presence of theAWS_LAMBDA_RUNTIME_API environment variable, which indicates the presence of the runtime API. If the runtime API is present, the script runsthe runtime interface client. Otherwise, the script runs the runtime interface emulator.

   The following example shows a typical script for a Node.js function.

   #!/bin/shif [-z"${AWS_LAMBDA_RUNTIME_API}" ];thenexec /usr/local/bin/aws-lambda-rie /usr/bin/npx aws-lambda-ricelseexec /usr/bin/npx aws-lambda-ricfi

2. Download theruntime interface emulator for your target architecture (aws-lambda-rie for x86_64 oraws-lambda-rie-arm64 for arm64) from GitHub into your project directory.

3. Install the emulator package and changeENTRYPOINT to run the new script by adding the following lines to your Dockerfile:

   To use the default x86_64 architecture

   ADD aws-lambda-rie /usr/local/bin/aws-lambda-rieENTRYPOINT ["/entry_script.sh" ]

   To use the arm64 architecture:

   ADD aws-lambda-rie-arm64 /usr/local/bin/aws-lambda-rieENTRYPOINT ["/entry_script.sh" ]

4. Build your image locally using the docker build command.

   docker build -t myfunction:latest.

5. Run your image locally using the docker run command.

   docker run -p 9000:8080 myfunction:latest

You install the runtime interface emulator to your local machine. When you run the container image, you set the entry point to be the emulator.

1. From your project directory, run the following command to download the RIE (x86-64 architecture) from GitHub and install it on your local machine.

   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

   To download the RIE for arm64 architecture, use the previous command with a different GitHub download url.

   https://github.com/aws/aws-lambda-runtime-interface-emulator/releases/latest/download/aws-lambda-rie-arm64 \

2. Run your Lambda image function using the docker run command.

   docker run -d -v~/.aws-lambda-rie:/aws-lambda -p 9000:8080 myfunction:latest \    --entrypoint /aws-lambda/aws-lambda-rie<image entrypoint><(optional) image command>

   This runs the image as a container and starts up an endpoint locally atlocalhost:9000/2015-03-31/functions/function/invocations.

3. Post an event to the following endpoint using a curl command:

   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.

aws-lambda-rie can be configured through Environment Variables within the local running Image.You can configure your credentials by setting:

• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY
• AWS_SESSION_TOKEN
• AWS_REGION

You can configure timeout by settingAWS_LAMBDA_FUNCTION_TIMEOUT to the number of seconds you want your function to timeout in.

The rest of these Environment Variables can be set to match AWS Lambda's environment but are not required.

• AWS_LAMBDA_FUNCTION_VERSION
• AWS_LAMBDA_FUNCTION_NAME
• AWS_LAMBDA_FUNCTION_MEMORY_SIZE

You can use the emulator to test if your function code is compatible with the Lambda environment, executes successfullyand provides the expected output. For example, you can mock test events from different event sources. You can also useit to test extensions and agents built into the container image against the Lambda Extensions API. This componentdoesnot emulate the orchestration behavior of AWS Lambda. For example, Lambda has a network and securityconfigurations that will not be emulated by this component.

• You can use the emulator to test if your function code is compatible with the Lambda environment, runs successfully and provides the expected output.
• You can also use it to test extensions and agents built into the container image against the Lambda Extensions API.
• This component doesnot emulate Lambda’s orchestration, or security and authentication configurations.
• The component doesnot support X-ray and other Lambda integrations locally.
• The component supports only Linux, for x86-64 and arm64 architectures.

SeeCONTRIBUTING for more information.

This project is licensed under the Apache-2.0 License.