Viburnum

Viburum - it's a small framework built on top of AWS CDK to simplify development and deploying AWS Serverless web applications.

Installing

Package consist of two pats primitives that help to describe your handlers and resources and deployer that will convert primitives into CloudFormation using CDK.

Installing only primitives

pip install viburnum

Installing with deployer

pip install "viburnum[deployer]"

Lambda function will require only primitives to work correctly. That's why it's recommended to add viburnum into requirements.txt and viburnum[deployer] into requirements-dev.txt

Project structure

Each Lambda function handler is represented as folder with handler.py inside and other files if required.

Example handler.py:

from viburnum.application import Request, Response, route

@route("/tests/{id}", methods=["GET"])
def get_test(request: Request, test_queue):
    print(f"Get test: {request.path_params.get('id')}")
    return Response(200, {})

In the root folder you need to have app.py file with Application, this file used by deployer and CDK to determine all related resources.

Example app.py

import aws_cdk as cdk
from viburnum.deployer.builders import AppConstruct
from viburnum.application import Application, Sqs

from functions.api.get_test.handler import get_test

app = Application("TestApp")
# Handlers
app.add_handler(get_test)

context = cdk.App()
AppConstruct(context, app)
context.synth()

All logic that shared across all lambdas, must be placed inside shared folder, and it will plugged into Lambda as a Layer.

Recommended structure

├── functions
│   ├── __init__.py
│   ├── api
│   │   ├── __init__.py
│   │   ├── some_api
│   │   │    ├── __init__.py
│   │   │    ├── handler.py
│   │   │    └── ...
│   │   │
│   │   └── ...
│   │   
│   ├── jobs
│   │   ├── __init__.py
│   │   ├── some_job
│   │   │    ├── __init__.py
│   │   │    ├── handler.py
│   │   │    └── ...
│   │   │
│   │   └── ...
│   │   
│   └── workers
│       ├── __init__.py
│       ├── some_job
│       │    ├── __init__.py
│       │    ├── handler.py
│       │    └── ...
│       │
│       └── ...
│      
├── shared
│   ├── __init__.py
│   └── ...
│
├── app.py
├── requirements-dev.txt
└── requirements.txt

CLI tool

Viburnum deployer include CLI tool that helps initializing project and creating a new handlers. After initializing project folder with cdk init app --language python you can call virburnum init, that command will change some files so Virburnum can work correctly. There is command for creating new handlers virburnum add [HANDLER_TYPE] that will create a handler.

Supported HANDLER_TYPE:

• api
• worker
• job

Example app

Simple example app