Publish or Update AWS Lambda Layer for python

• Objective
• Usage
  • Inputs
  • Example
• Published Layer Name

Objective

A Lambda layer is a .zip file archive that contains supplementary code or data. Layers usually contain library dependencies, a custom runtime, or configuration files. Layers promote code sharing and separation of responsibilities so that you can iterate faster on writing business logic.

Reasons to use layers are listed below:

• To reduce the size of your deployment packages.
• To separate core function logic from dependencies.
• To share dependencies across multiple functions.
• To use the Lambda console code editor.

Objective of this action is to streamline the process of publishing an AWS Lambda Layer in GitHub workflows, eliminating the need to manually write code.

Usage

Usage of this action requires following parameters.

Inputs

Name	Type	Required	Description
python_version	string	No	Python Version, default value is 3.7
layer_name	string	Yes	Name of AWS Lambda Layer
layer_directory	string	No	Path of requirements.txt file in repository.
bucket_name	string	Yes	S3 bucket name where lambda layer will be uploaded
bucket_path	string	No	Folder path inside the S3 bucket (Optional)
aws_account_id	string	No	An AWS Account ID to grant layer usage permissions to, default value is * to share with all accounts

The python_version only accepts versions of python mentioned in AWS Lambda docs; Lambda runtimes.

The layer_name can be anything you prefer. This is restricted to letters, numbers, hyphens, and underscores.

The layer_directory is the folder path in git repository where requirements.txt file exists. It is optional in case requirements.txt file is in root of repository.

The bucket_name parameter is the name of S3 bucket in which you want to upload the lambda layer.

The bucket_path parameter is the folder path for lambda layer in S3 bucket. Use the format lambda-layers/ to add S3 path.

The aws_account_id parameter is an AWS account number with which you want to share the lambda layer. To share it with all accounts, use "*".

Example

name: publish-python-lambda-layer
on:
  push:
    branches:
      - dev
jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Configure AWS Credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: ${{ secrets.AWS_REGION }}

      - name: Publish Lambda layer
        uses: UmerMuxhal/python-lambda-layer@v1
        with:
          python_version: 3.8
          layer_name: "my-lambda-layer"
          layer_directory: "requirements_folder"
          bucket_name: "my-s3-bucket"
          bucket_path: "layers/"
          aws_account_id: ${{ secrets.AWS_ACCOUNT_ID }}

Published Layer Name

The ARN of published lambda layer will look like the following.

arn:aws:lambda:<AWS_REGION>:<AWS_ACCOUNT_ID>:layer:<layer_name>-<python_version>:<layer_version>