Busie Flask Helper

A package to help with common initialization code across Busie Flask projects

Helpful for use with the application factory pattern. Allows for modularization of initialization code, such that factories are not cluttered with boilerplate initialization

Installation

pip install busie-flask-helper

Usage

# in app.py, or wherever application initialization lives
from busie_flask import FlaskHelper
helper = FlaskHelper('abs/path/to/project/')
db = helper.db
auth = helper.auth
cache = helper.cache

# Other Initialization Code omitted

def create_app():
    app = Flask(__name__)
    # Other App Factory initialization omitted

    # this invocation initializes all of the helper objects with the application
    # this includes migration commands, models, views, auth, cache client, orm
    helper.init_app(app, 'relative/path/to/models', '/relative/path/to/views')

    return app

# in some module, maybe an API View
from flask import request, render_template
from src.app import auth, app

@app.route('/foo')
@auth.requires_web_auth
def foo():
    return render_template('foo.html')

class SomeView(MethodView):
    decorators = [auth.require_api_auth]

    def get(self):
        if auth.requires_permission('SomeView:bar'):
            return 'ok', 200
        raise AuthError({'code': 'some_error', 'description': 'something went wrong'}, 403)

API

FlaskHelper

Public Properties

• db <[SQLAlchemy] (https://flask-sqlalchemy.palletsprojects.com/en/2.x/)>
• auth <[AuthHelper] (#authhelper)>
• cache <[CacheClient] (#cacheclient)>

Public Methods

• FlaskHelper(root_dir, app=None, models_dir=None, views_dir=None)
  • param root_dir: The root directory of the project, best practice to pass an abspath here. if your application lives in src/app then your root dir should be src/
  • See init_app method documentation for specifics on the other params
• init_app(self, app, models_dir, views_dir)
  • param app: A Flask application instance
  • param models_dir: Relative path to the models directory, with respect to the root_dir that the helper was initialized with
  • param views_dir: same as models_dir, but for views

AuthHelper

This is an Auth0 Integration. It comes with helpful decorators for protecting both API and Web App views. It also automatically adds /login, /callback, and /logout routes to your application for Auth0 Authorization Code Flow Authentication. Note that this feature cannot be disabled at this time, but this ability will be added in a future release. In web applications and API's, merely authenticating should never be enough to gain access to a protected resource.

Public Properties

None

Public Methods

• AuthHelper(app=None): Constructor
• init_app(self, app): Initialize the AuthHelper with a Flask application
  • param app: A Flask application instance. app.config must have AUTH0_AUDIENCE AUTH0_DOMAIN and AUTH0_ALGORITHMS
• requires_api_auth(self, f): A decorator for views that require the auth code with pkce flow.
• requires_web_auth(self, f): A decorator for views that require the auth code flow (no pkce)
• get_rsa_key_from_unverified_token(self, token): Determines the RSA key to use from the token's kid
  • param token: A json web token with appropriate headers
  • return: rsa_key (dict) or None
• handle_rsa_decode(self, rsa_key, token): decodes the token using rsa
  • param rsa_key: dict representation of an RSA key
  • param token: a json web token with necessary claims
• requires_scope(self, required_scope): determine if the auth token has the provided required scope
  • param required_scope: string, the desired scope for the resource
  • return: bool
• requires_permission(self, required_permission): determine if the auth token has the provided required permission
  • param required_permission: string, the desired permission for the resource
  • return: bool
• static -> get_token_auth_header(): gets the auth header from the request context and formats it properly
  • return: str

CacheClient

Public Properties

• redis: The redis instance. Allows for direct interation with the python Redis API

Public Methods

• CacheClient(app=None): Constructor
• init_app(self, app): Initialize the redis client with application.
  • param app: A Flask application instance. app.config must have REDIS_HOST REDIS_PORT and REDIS_DB. NOTE REDIS_PASSWORD is also used, but this method will not throw without it
• get: Alias for redis.get
• set: Alias for redis.set