Hyper Quart Rest API

This is a starter project to start serving API's with use of the new async/await keywords in Python and make use of ASGI (Asynchronous Server Gateway Interface). Ideally this should lead to performance increases vs. a traditional WSGI-served app, which is common with many Flask/Django setups - 3x faster Flask apps

Installation

• Clone the repo: git clone git@github.com:edmundpf/HyperQuartRestApi.git
• Create the LOGS directory for hypercorn log files: mkdir LOGS
• Install the python requirements: python3 -m pip install requirements.txt

Flask-to-Quart Migration

• Quart shares the same modules/functions as Flask, so replacing flask with quart and Flask with Quart in your imports/any occurences in your code will leave you with a working app.
• Additional changes are needed to take advantage of async calls though, your route functions must make use of the async/await keywords...
  • Flask example:

    @app.route('/')
    def route():
      data = request.get_json()
      return render_template_string("Hello {{name}}", name=data['name'])

  • Quart example:

    @app.route('/')
    async def route():
      data = await request.get_json()
      return await render_template_string("Hello {{name}}", name=data['name'])

  • The following common methods will need the await keyword and must be placed in an async function block

    await request.data
    await request.get_json()
    await request.form
    await request.files
    await render_template()
    await render_template_string()

• For more information see the Quart Documentation - Migration from Flask

Deployment

• The app can be served with the command hypercorn app:app
• This repo includes an example DEPLOY shell script that will require some modifications to use:

  cat > /usr/bin/nonhup
  nohup "$@" </dev/null >/dev/null 2>&1 &
  ^C
  chmod +x /usr/bin/nonhup
  chmod +x DEPLOY

• Deploy with the command ./DEPLOY
  • The nonhup command that was added is a wrapper for nohup that prevents a command from hanging in the console and also prevents the nohup.out file from being created
• The included deployment script serves the app on localhost:5000, automatically reloads after adding/changing files in the app directory, and redirects the error logs to LOGS/app.log
• Further customization options for Hypercorn - Hypercorn Documentation