Extensive Flask boilerplate using best practices with a focus on implementing an OAuth 2.0 client.

• OAuth 2.0 - Server-side authorization for Google, Facebook.
• Flask-Login for local authorization, using Argon2 password hashing.
• Flask app design using Blueprints and Application Factories.
• Bootstrap 4 Beta as frontend.
• SQLAlchemy ORM using relationships, constraints, joins, labels, ...
• Loading data from JSON into database.
• Flask-WTF forms with CSRF Protection, Jinja2 macros and dynamically generated QuerySelectField.
• Using Flasks built-in integration of click CLI instead of Flask-Script.
• REST API - JSON endpoints.
• Extensive error handling, logging to console and log file.
• Configuration from file.
• Unit Tests with Coverage.
• Pipenv as Python packaging tool.

There are many libraries available for OAuth 2.0 authorization. Google's oauth2client got recently deprecated and now they recommend google-auth with OAuthLib but their docs are not yet updated. Rauth is unmaintained. I decided to use Flask-OAuthlib, it uses Requests-OAuthlib which is a high-level client library built on OAuthLib & Requests. Please note that Google has also just released one-tap sign-up an auto sign-in on websites.
Currently supported providers: Google, Facebook.

Update @ 2018-01-08: apparently Flask-OAuthlib is now also deprecated and will be replaced by Authlib...

Keeping the extensions to a minimum, others can be easily integrated.

• Flask-OAuthlib
• Flask-Login
• Flask-SQLAlchemy
• Flask-WTF
• CSRF Protection
• Flask-DebugToolbar

Have a look in the Wiki to see how it looks.

Before you can integrate sign-in to your websites, set up your app at Google & Facebook.

Create a Google API Console project and client ID.
Authorized JavaScript origins: http://localhost:5000
Authorized redirect URIs: http://localhost:5000/oauth2/sign-in/google/authorized
Add your client_id and client_secret in myapp/oauth2/google_client_secrets.json

Create and retrieve a Facebook App ID on the App Dashboard.
Open Products > Facebook Login and enable Client OAuth Login and Web OAuth Login.
Valid OAuth redirect URIs: http://localhost:5000
Add your App ID and App Secret to myapp/oauth2/facebook_client_secrets.json

Generate your own secret keys and add them to files run_development.sh, run_testing.sh, run_testing_with_coverage.sh.

Create a virtual environment and start one of the shell scripts, this example uses Pipenv.

pip3 install --user pipenv
pipenv install #This installs everything from the pipfile.
./run_development.sh

Adding multiple ways of sign in for websites, using provider APIs, JavaScript, ... I really hope that with your contributions, we can keep improving this template.

See the LICENSE file for license rights and limitations (MIT).