FaastAPI

Easily create OpenFaas functions built on top of FastAPI Python framework

Warning:

This project is in its early phase. It might be subject to a lot of changes and many features might be added/removed.

Overview

FaastAPI is built on top of FastAPI framework, pydantic library, and jinja2 library.

It allows developers to quickly generate OpenFaas functions.

Several plugins can be used to quicly set up a rest API. A command line interface can be installed with the package so that functions can be tested locally.

Installation

You can install package using pip:

pip install faastapi

By default, the command line interface and plugins are not installed. You can choose to install the cli using the cli extra:

pip install faastapi[cli]

Example

A simple Faastapi function file (by default Faastapi search files named faastapi.yml) can be as follow:

---
apiversion: v1

meta:
  name: hello-faastapi
  version: 0.3.4

  image: gcharbon/hello-fastapi
  tags:
    - test
    - demo
  description: A dummy function to demonstrate Faastapi

build:
  plugins:
    basic-auth:
      username: admin
      password: password
    mongodb:
      host:  127.0.0.1
      port: 27017
      database: demo
    sqlite:
      uri: sqlite:///example.db
    async-sqlite:
    instrumentation:

run:
  script: hello.py
  function: say_hello
  method: post
  input:
    name: 
      type: str
      default: World
  output:
    message: str
    date: datetime
    drivers: Dict[str,str]

Considering the file hello.py is present next to faastapi.yml with the following content:

import datetime


def say_hello(context, name):
    return {
        "message": f"Hello {name}",
        "date": datetime.datetime.now(),
        "drivers": {
            "mongodb": str(context.mongodb),
            "sqlite": str(context.sql),
            "async-sqlite": str(context.async_sql),
        },
    }

Note: As you can see function must always accept an argument named context. In this case, since sqlite, async-sqlite and mongodb plugins where specified, clients are available in the context.

When the user run faastapi function new -f faastapi.yml openfaas, an OpenFaas function will be generated in the openfaas directory. This function can then be deployed to OpenFaas with faas-cli:

cd openfaas/
faas-cli up -f function.yml

You can then try the function on OpenFaas portal (http://<OPENFAAS_URL>):

You can also access the documentation of the function at http://<OPENFAAS_URL>/function/hello-faastapi/docs:

List of available plugins

Security plugins:

• basic-auth: Enables a basic authentication in your application.

Note: Username and password can be configured as in the above example

• oauth2-password: Enable simple oauth2 with password and bearer.

Note: At this moment, configuration of user database is not possible, thus usage is limited to default values (username: admin, password: secret)

Databases plugins:

• sqlite: Injects an sqlalchemy Session with sqlite3 engine into the context by default.
• postgres: Injects an sqlachemy Session with psycopg2 engine into the context by default.
• mysql: Injects an sqlalchemy Session with mysqlclient engine into the context by default.
• async-sqlite: Injects a databases.Database instance with aiosqlite engine into the context by default.
• async-postgres: Injects a databases.Database instance with asyncpg engine into the context by default.
• async-mysql: Injects a databases.Database instance with aiomysql engine into the context by default.

Note: All those plugins accept a single configuration variable: uri

• mongodb: Injects a pymongo.Database instance into the context.

Note: MongoDB plugin can be configured using the variables: host (default to 127.0.0.1), port (default to 27017) and database (default to test)

• redis: Injects a Redis instance into the context.

Note: Redis plugin can be configured using the variables: host (default to 127.0.0.1), port (default to 6379) and db (default to 0)