Mangum CLI

This package provides a command-line interface for generating AWS Lambda & API Gateway deployments used with Mangum.

Note: This is a work-in-progress. PRs welcomed.

Requirements: Python3.7+

Installation

pip install mangum-cli

Commands

mangum init - Create a new deployment configuration.

mangum build - Create a local build.

mangum deploy - Deploy the packaged project.

mangum package - Package the local build.

mangum all - build, package, and deploy.

mangum describe - Retrieve the endpoints for the deployment.

mangum validate - Validate the AWS CloudFormation template.

mangum delete - Delete the CloudFormation stack.

Tutorial

The steps below outline a basic FastAPI deployment, however you should be able to use any ASGI framework/application with the adapter.

Step 1 - Create a local project

First, create a new directory app/, this is the folder that will contain the main application code and function handler.

Then create a file asgi.py with the following:

from mangum import Mangum
from fastapi import FastAPI


app = FastAPI()


@app.post("/items/")
def create_item(item_id: int):
    return {"id": item_id}


@app.get("/items/")
def list_items():
    items = [{"id": i} for i in range(10)]
    return items


@app.get("/")
def read_root():
    return {"Hello": "World!"}


handler = Mangum(app)

This demonstrates a basic FastAPI application, the most relevant part is:

handler = Mangum(app)

The handler variable will be used as the handler name defined in the CloudFormation template to be generated later.

Lastly, create a requirements.txt file to include Mangum and FastAPI in the build:

mangum
fastapi

Step 2 - Create a new deployment configuration

Run the following command with a name for the project (required) and optionally include the name of an S3 bucket, the region and the runtime version (these values can be changed later):

mangum init <name> [bucket-name] [region-name] [runtime]

After defining the configuration a mangum.yml file will be generated, the current directory should now look this:

├── app
│   └── asgi.py
├── mangum.yml
└── requirements.txt

Step 3 - Create a local build

Run the following command to create a local application build:

mangum build

This will create a build/ directory containing the application code and any dependencies included in requirements.txt.

Step 4 - Package the local build

Run the following command to package the local build:

mangum package

This wraps the AWS CLI's package command, it uses the definitions in mangum.yml to produce a packaged.yml file and a template.yml file.

Step 5 - Deploy the packaged build

Run the following command to deploy the packaged build:

mangum deploy

This wraps the AWS CLI's deploy command. It may take a few minutes to complete. If successful, the endpoints for the deployed application will be displayed in the console.

Step 6 - Delete CloudFormation stack

Run the following command to delete the CloudFormation stack:

mangum delete

Appendix.A - Enable shell completion.

You can enable shell completion by running the install option.

mangum complement bash

Candidates can be displayed by pressing the tab key.

$ mangum [TAB][TAB]
all            complement     delete         describe       package
build          create-bucket  deploy         init           validate

Appendix.B - build, package, and deploy.

If you want to execute build, package, and deploy sequentially, do as follows:

mangum all