LambdaMaker

LambdaMaker is a simple, modular Python utility that automates the creation, packaging, configuration, and deployment of AWS Lambda functions, especially those processing and/or triggered from s3, using only standard Python and boto3.

🚀 Features

• Package Python-based Lambda functions from local code and dependencies
• Create an IAM role with appropriate permissions
• Deploy the Lambda function to AWS
• Set environment variables from a .env file
• Optionally configure S3 bucket triggers for Lambda execution
• Supports a JSON config file for consistent and repeatable deployment

📦 Installation

You can install LambdaMaker directly from PyPI:

pip install lambdamaker

⚙️ Requirements

LambdaMaker was developed and tested using Python 3.12, which is currently supported by AWS Lambda. However, the version can be configured (see python_version below).

• You must have valid AWS credentials configured in ~/.aws (via aws configure or similar).
• If using S3 triggers, the S3 bucket must already exist.
• Docker must be installed and running if use_docker is set to true. If Docker Desktop is required, ensure it is manually started before running.
• If openai, pydantic, or other compiled dependencies are used, setting use_docker is strongly recommended.

🔧 Configuration

All routines look for config.json, requirements.txt, and my.env in the same working directory by default. You can override this by passing a working_dir parameter to any of the functions.

By default, any additional Python source files specified under mylib_files in the configuration will be copied from a directory named mylib in the user's home folder ($HOME/mylib). You may override this by passing the mylib_dir parameter with a different path.

If you're using the example project in the mylambda folder in this repository, you can run the tool using working_dir="mylambda" and mylib_dir="." to pick up helloworld.py from the same folder.

Common Parameters

• replace (bool, default: False): If True, existing AWS resources such as the Lambda function, IAM role, or S3 triggers will be updated or replaced. If False, existing resources are left untouched.
• working_dir (Path or str, optional): Specifies the directory where config.json, requirements.txt, and my.env are located. Defaults to the current working directory.
• mylib_dir (Path or str, optional): Directory from which to copy the files listed under mylib_files. Defaults to $HOME/mylib.
• use_docker (bool, default: False): Enables Docker-based builds to ensure compatibility with AWS Lambda Linux environment, particularly for packages requiring native binaries. When set to true, Docker must be running or the user will be prompted.
• python_version (str, default: "3.12"): Specifies the Python runtime for both Docker image used during zip creation and the AWS Lambda deployment.

Example config.json

{
  "lambda_name": "s3lambda",
  "entry_file": "helloworld.py",
  "entry_func": "lambda_handler",
  "mylib_files": ["helloworld.py"],
  "output_dir": ".",
  "memory_size": 128,
  "timeout": 120,
  "ephemeral_storage": 512,
  "role_name": "s3lambda",
  "s3_buckets": ["*"],
  "trigger_bucket": null,
  "trigger_filetypes": [],
  "use_docker": false,
  "python_version": "3.12"
}

• The entry_file must be either listed in mylib_files or included in your requirements.txt.
• my.env uses standard .env file format:

USERNAME=World

Environment variables defined here will be injected into your Lambda runtime.

✅ Example Usage

from lambdamaker import (
    create_iam_role,
    create_lambda_zip,
    create_or_update_lambda,
    configure_s3_trigger
)

create_iam_role()
create_lambda_zip()
create_or_update_lambda()
configure_s3_trigger()

Or call the main function:

from lambdamaker import main
main()  # safer default: replace=False

To use the included sample from the /mylambda folder:

main(working_dir="mylambda", mylib_dir="mylambda")

🔐 IAM and Security

The tool will:

• Automatically create an IAM role if it doesn't exist
• Attach AWSLambdaBasicExecutionRole
• Optionally grant access to S3 buckets (full or restricted)

🙣 S3 Triggers

To enable S3 triggers:

• Set trigger_bucket to a valid bucket name
• Set trigger_filetypes to a list of suffixes like [".json", ".mp4"]

The tool will:

• Add invoke permission for the bucket
• Create a trigger per suffix
• Preserve triggers for other Lambda functions on the bucket

📄 License

MIT License

Contributions and issue reports are welcome!