lambda-layer-builder's Introduction

AWS Lambda Layer Builder

A docker-based utility to create lambda layer packages for Python runtime on demand.

Prerequisites

Clone this repo & follow the steps in windows-commands.bat

Build Docker Image from Dockerfile
```
docker build -t layer-builder-image .
```

Run a Container from the Image

docker run -td --name=layer-builder layer-builder-image

Update requirements.txt (local) to list the libraries and versions your project needs. Example:
```
pandas==1.4.2
requests==2.27.1
```

Copy requirements.txt from host to container

docker cp .\requirements.txt layer-builder:/

Run install.sh inside the container

docker exec -i layer-builder /bin/bash < ./install.sh

This script performs the following steps:
- creates and activates a python virtualenv
- installs the requested libraries (requirements.txt) from pip
- creates a zip file named python.zip with all installed packages
Copy the python.zip thus created from container to host
```
docker cp layer-builder:/python.zip python.zip
```

Stop and delete the container

docker stop layer-builder
docker rm layer-builder

⚠️Do NOT rename the zip file. AWS Lambda needs the file to be named python.zip. This zip file can be uploaded to AWS console when creating a new AWS Lambda Layer.

💡 Tip: For storing the zip file for future usage, since you cannot rename the zip file, you can instead create a folder with a descriptive name that describes the contents of the python.zip and move the zip file to that folder. You may also choose to place the requirements.txt file that was used to generate that zip file alongside the zip in same folder.