Deploy Python Lambda functions with container images

You can deploy your Lambda function code as a container image. AWS provides the following resources to help you build a container image for your Python function:

• AWS base images for Lambda

  These base images are preloaded with a language runtime and other components that are required to run the image on Lambda. AWS provides a Dockerfile for each of the base images to help with building your container image.

• Open-source runtime interface clients

  If you use a community or private enterprise base image, add a runtime interface client to the base image to make it compatible with Lambda.

AWS base images for Python

AWS provides the following base images for Python:

Tags	Runtime	Operating system	Dockerfile
3, 3.8	Python 3.8	Amazon Linux 2	Dockerfile for Python 3.8 on GitHub
3.7	Python 3.7	Amazon Linux 2018.03	Dockerfile for Python 3.7 on GitHub
3.6	Python 3.6	Amazon Linux 2018.03	Dockerfile for Python 3.6 on GitHub
2, 2.7	Python 2.7	Amazon Linux 2018.03	Dockerfile for Python 2.7 on GitHub

Docker Hub repository: amazon/aws-lambda-python

Amazon ECR repository: gallery.ecr.aws/lambda/python

Python runtime interface clients

Install the runtime interface client for Python using the pip package manager:

pip install awslambdaric

For package details, see Lambda RIC on the Python Package Index (PyPI) website.

You can also download the Python runtime interface client from GitHub.

Deploying Python with an AWS base image

When you build a container image for Python using an AWS base image, you only need to copy the python app to the container and install any dependencies.

To build and deploy a Python function with the python:3.8 base image.

1. On your local machine, create a project directory for your new function.

2. In your project directory, add a file named app.py containing your function code. The following example shows a simple Python handler.

   import sys
   def handler(event, context):
       return 'Hello from AWS Lambda using Python' + sys.version + '!'        

3. Use a text editor to create a Dockerfile in your project directory. The following example shows the Dockerfile for the handler that you created in the previous step.

   FROM public.ecr.aws/lambda/python:3.8
   
   COPY app.py   ./
   CMD ["app.handler"]      

4. To create the container image, follow steps 4 through 7 in Create an image from an AWS base image for Lambda.

Create a Python image from an alternative base image

For an example of how to create a Python image from an Alpine base image, see Container image support for Lambda on the AWS Blog.