Terraform AWS Lambda Python Layer Module

This Terraform module creates an AWS Lambda layer for specified Python packages. It supports both public and private Python package repositories, such as PyPI or Artifactory, allowing you to manage dependencies flexibly for your Lambda functions.

Example Usage

The following module definition can be used to create a lambda layer.

1. Basic Usage (Public PyPI)

Use the module without specifying pip_repo_config if all packages are available in public PyPI.

module "public_lambda_layer" {
  source        = "git::https://github.com/vickyboston20/terraform-aws-python-lambda-layer.git?ref=1.0.0"
  layer_name    = "public-lambda-layer"
  package_names = [
    "boto3",
    "pyotp==2.9.0"
  ]
  compatible_runtimes = [
    "python3.10",
    "python3.11",
    "python3.12"
  ]
}

2. Advance Usage (Private Artifactory)

Set pip_repo_config to define additonal repository settings for private packages.

module "private_lambda_layer" {
  source        = "git::https://github.com/vickyboston20/terraform-aws-python-lambda-layer.git?ref=1.0.0"
  layer_name    = "private-lambda-layer"
  package_names = [
    "private_sample_lib==1.0.13"
  ]
  pip_repo_config = [
    {
      extra_index_url = "https://example.com/artifactory/api/pypi/pypi-repos/simple"
      trusted_host    = "example.com"
    }
  ]
  compatible_runtimes = [
    "python3.10",
    "python3.11",
    "python3.12"
  ]
}

3. Force Rebuild the Lambda Layer

To rebuild the Lambda layer on demand, set the force_rebuild variable to true. This triggers the regeneration of the Lambda Layer, even if there are no changes in the packages

module "lambda_layer_with_force_rebuild" {
  source        = "git::https://github.com/vickyboston20/terraform-aws-python-lambda-layer.git?ref=1.0.0"
  layer_name    = "force-rebuild-lambda-layer"
  package_names = [
    "boto3",
    "pyotp==2.9.0"
  ]
  compatible_runtimes = [
    "python3.10",
    "python3.11",
    "python3.12"
  ]
  force_rebuild = true
}

Input Variables

Variable Name	Type	Default	Description
layer_name	string	required	Specifies the name for the Lambda layer.
package_names	list(string)	required	List of Python packages to include in the Lambda layer.
pip_repo_config	list(object({ extra_index_url = string, trusted_host = string }))	[]	Optional configuration for private package repository. Must contain only one entry if specified.
compatible_runtimes	list(string)	[]	List of compatible Python runtimes (e.g., python3.11, python3.12).
force_rebuild	bool	false	If set to true, forces the Lambda layer to rebuild even if no changes are detected.

Output

Name	Description
lambda_layer_arn	The ARN of the created Lambda layer.

Using lambda_layer_arn in a Lambda function

The module outputs lambda_layer_arn, which you use to attach this layer to your lambda function.

resource "aws_lambda_function" "sample_lambda_function" {
  function_name = "sample-function"
  runtime       = "python3.12"
  handler       = "index.handler"
  role          = aws_iam_role.lambda_role.arn
  filename      = "path/to/lambda/function.zip"
  layers        = [module.private_lambda_layer.lambda_layer_arn]
}