Build Python AWS Lambda deployment packages with Docker

We are building for Python 3.8 and on the latest amazonlinux 2. You can either use lambda.zip directly or add lambda-layer.zip as a layer to your lambda_function.py. Python binary is in /opt/bin/python3.8.

Why?

• Logging in to EC2 and creating a deployment package by hand is clumsy. Instead, script package creation around the amazonlinux 2 image.

How to use

• Mount /src as a docker volume, this is where you should put your lambda code.
• Deployment packages lambda.zip and lambda-layer.zip are written to /deploy directory.
• Modify and mount run.sh script to /opt/run.sh.
• Pass environment variables:
  • GIT_REPO - clone this git repo into /src.
  • PIP_PACKAGES - space separated list of packages you want to add to your lambda zip.
  • REM_LAMBDA_FILE - (OPTIONAL) remove the original lambda_function.py file from lambda-layer.zip if you don't need it there.

$ docker pull sam2kb/lambda

$ docker run --rm \
  -v "$(pwd)/src:/src" \
  -v "$(pwd)/run.sh:/opt/run.sh" \
  -v "$(pwd)/deploy:/deploy" \
  -e GIT_REPO="https://github.com/some/repo" \
  -e PIP_PACKAGES="cryptography imap_tools " \
  -e REM_LAMBDA_FILE="lambda_function.py" \
  sam2kb/lambda \
  bash /opt/run.sh

Or run with docker-compose

Remember to modify docker-compose.yml file first

$ docker-compose run --rm lambda

Customize

Modify run.sh to suit your own purposes

Use another Python version

Pass a build ARG with any other Python version as such PYTHON_VER=3.8.0

$ docker build --build-arg PYTHON_VER=3.8.0 -t mylambda .

Or with docker-compose

$ docker-compose build --build-arg PYTHON_VER=3.8.0