Quart§

To run apps built with the Quart web framework using Unit:

Install Unit with a Python 3.5+ language module.
Create a virtual environment to install Quart’s PIP package:
```
$ cd /path/to/app/
$ python3 --version
      Python 3.Y.Z
$ python3 -m venv venv
$ source venv/bin/activate
$ pip install quart
$ deactivate
```
Warning

Create your virtual environment with a Python version that matches the language module from Step 1 up to the minor number (3.Y in this example). Also, the app type in Step 5 must resolve to a similarly matching version; Unit doesn’t infer it from the environment.

Let’s try a WebSocket-enabled version of a tutorial app, saving it as /path/to/app/asgi.py:

from quart import Quart, websocket

app = Quart(__name__)

@app.route('/')
async def hello():
    return '<body><h1>Hello, World!</h1></body>'

# Let's add WebSocket support to the app as well
@app.websocket('/ws')
async def ws():
    while True:
        await websocket.send('Hello, World!')

Run the following command so Unit can access the application directory:
```
# chown -R unit:unit /path/to/app/
```
Note

The unit:unit user-group pair is available only with official packages, Docker images, and some third-party repos. Otherwise, account names may differ; run the ps aux | grep unitd command to be sure.

For further details, including permissions, see the security checklist.

Next, prepare the Quart configuration for Unit (use real values for type, home, and path):

{
    "listeners": {
        "*:80": {
            "pass": "applications/quart"
        }
    },

    "applications": {
        "quart": {
            "type": "python 3.Y",
            "path": "/path/to/app/",
            "home": "/path/to/app/venv/",
            "module": "asgi",
            "callable": "app"
        }
    }
}

Upload the updated configuration. Assuming the JSON above was added to config.json:

# curl -X PUT --data-binary @config.json --unix-socket \
       /path/to/control.unit.sock http://localhost/config/

Note

The control socket path may vary; run unitd -h or see Startup and Shutdown for details.

After a successful update, your app should be available on the listener’s IP address and port:

$ curl http://localhost

      <body><h1>Hello, World!</h1></body>

$ wscat -c ws://localhost/ws

      < Hello, World!
      < Hello, World!
      < Hello, World!
      ...

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v. 1.33.0

Quart§