spawner/render/__main__.py

"""Web Server Gateway Interface with autoreload to render spawner template.

Usage: `python -m render`

"""
from traceback import format_exc

from flask import Flask, render_template, request
from glicid_spawner.form import TEMPLATES, options_from_form
from glicid_spawner.micromamba import MicromambaEnv
from glicid_spawner.resources import CPU, GPU, RAM
from livereload import Server

# Dummy username and python environments
USERNAME = 'john-doe'
ENVS = [
    MicromambaEnv('USER', 'foo', f'/{USERNAME}/envs/foo'),
    MicromambaEnv('USER', 'bar', f'/{USERNAME}/envs/bar'),
    MicromambaEnv('GLOBAL', 'baz', '/global/envs/baz'),
]
OPTIONS = {
    'username': USERNAME,
    'envs': ENVS,
    'cpus': CPU,
    'rams': RAM,
    'gpus': GPU,
}


# Flask app
app = Flask(__name__)
app.debug = True


@app.route('/')
def home():
    """Form spawner home page."""
    return render_template(
        'form.html',
        spawner_options_form=TEMPLATES.get_template('spawner_form.jinja').render(**OPTIONS),
        options=OPTIONS,
    )


@app.route('/submit', methods=['POST'])
def submit():
    """Reformat form data and extract spawner options.

    https://jupyterhub.readthedocs.io/en/stable/reference/spawners.html#spawner-options-from-form

    """
    formdata = dict(request.form.lists())

    # Trying to parse the options from the formdata
    try:
        return render_template(
            'options.html', formdata=formdata, options=options_from_form(formdata)
        )
    except Exception:
        return render_template('options.html', formdata=formdata, err=format_exc())


def server_autoreload():
    """Start auto-reload server."""
    server = Server(app.wsgi_app)
    server.serve()


if __name__ == '__main__':
    server_autoreload()