Discourse SSO OIDC Bridge - A Python PyPI package and a Docker image

This Python package contains a Flask application that when deployed can be used as and endpoint for Discourse when setting up it's SSO. It will then be able to wrap a OIDC provider and avoid various limitations of not being setup as a Discourse SSO provider.

The Flask application can be deployed using a Docker image that is also within this repo and published to docker hub as consideratio/discourse-sso-oidc-bridge.

This repo was made standing on the shoulders giants who made most of the initial work. Thank you @fmarco76 and @stevenmirabito for the valuable work you have made!

• https://github.com/fmarco76/DiscourseSSO
• https://github.com/ComputerScienceHouse/DiscourseOIDC

I also did some Dockerfile refinements thanks to @greut's excellent Medium article.

Installation

Note that this only installs a Python package containing a Flask application, you must use gunicorn or another WSGI compatible webserver to host it and setup TLS etc.

pip install --upgrade discourse-sso-oidc-bridge-consideratio

To startup a the Flask app within a prebuilt Docker image, do the following.

docker run --rm -p 8080:8080 consideratio/discourse-sso-oidc-bridge

To actually use it, you should make it deployed in a way that it is accessible for discourse and its users, so it can redirect arriving users who wants to login to it. To do this, visit the discourse settings and search for sso.

NOTE: When you do this setup, you want to check and fill in enable sso, sso url, and sso secret. What you write in your sso secret should be repeated in your bridge configuration.

Bridge Configuration

These are common configuration options, but you can find some more exotic ones within default.py.

To configure these, you have two options.

• You can provide provide a Python based config file and set the CONFIG_LOCATION environment variable allowing the application to locate it.

  #######################
  # Flask Configuration #
  #######################
  
  DEBUG = True
  
  # NOTE: Your OIDC provider needs to have "Login redirect URIs" setup to the following
  # endpoint managed by flask-pyoidc:
  # https://discourse-sso.example.com/redirect_uri
  PREFERRED_URL_SCHEME = 'https'
  SERVER_NAME = 'discourse-sso.example.com'
  SECRET_KEY = 'my-secret-key-that-i-came-up-with-myself'
  
  # NOTE: Relates to OIDC_SESSION_PERMANENT as well.
  #       http://flask.pocoo.org/docs/1.0/config/#PERMANENT_SESSION_LIFETIME
  # NOTE: You may want to learn about the "maximum session age" setting in discourse
  #       as well.
  # PERMANENT_SESSION_LIFETIME = 2678400
  
  
  ################################
  # OpenID Connect Configuration #
  ################################
  
  # NOTE: Relates to PERMANENT_SESSION_LIFETIME as well.
  #       https://github.com/zamzterz/Flask-pyoidc#flask-configuration
  # OIDC_SESSION_PERMANENT = True
  
  # NOTE: If you add /.well-known/openid-configuration to your OIDC_ISSUER, you should get a bunch of JSON details back if you got it right.
  OIDC_ISSUER = 'https://my-oidc-provider.com'
  OIDC_CLIENT_ID = 'my-client-id-from-my-oidc-provider'
  OIDC_CLIENT_SECRET = 'my-secret-key-from-my-oidc-provider'
  OIDC_SCOPE = 'openid profile email offline_access'
  
  ###########################
  # Discourse Configuration #
  ###########################
  
  DISCOURSE_URL = 'https://discourse.example.com'
  DISCOURSE_SECRET_KEY = 'my-other-secret-that-i-came-up-with-myself'
  

• You can set environment variables with the same name as the config options. The default python config will look in these environment variables and use them if available.

OIDC Provider Configuration

You must have a client_id and client_secret from your OIDC issuer. The issuer must also accept redirecting back to <PREFERRED_URL_SCHEME>://<bridge_url>/redirect_uri, which for example could be https://discourse-sso.example.com/redirect_uri.

Development Notes

To make changes and test them

1. Clone the repo

2. Install pipenv using pip.

   pip install pipenv
   

3. Setup a virtual development environment

   pipenv install --dev
   
   # Optionally enter the environment
   pipenv shell
   

4. Run tests

   pipenv run pytest
   

Build and upload a PyPI release

1. Test, build and upload the package

   # Make sure you are up to date with what you have declared to require
   pipenv install --dev
   
   # Update changelog, fix requirements, etc.
   pipenv lock -r > requirements.txt
   
   # Run tests
   pipenv run pytest
   
   # Verify that the Dockerfile can build and start
   docker build --tag discourse-sso-oidc-bridge:local . && docker run --rm discourse-sso-oidc-bridge:local
   
   # Let PBR update the ChangeLog
   # FIXME: Can I update the ChangeLog in a more minimalistic way?
   pipenv run python setup.py install
   
   # Commit and tag to influence the PyPI version
   # PBR will look for the latest tag and then append development
   # versions based on your git commits since the latest tag.
   git add .
   git commit
   
   
   TAG=$(pipenv run python -c 'from pbr.version import VersionInfo; print(VersionInfo("discourse_sso_oidc_bridge").version_string())')
   git tag -a $TAG -m "Release $TAG"
   
   # Build the package
   pipenv run python setup.py sdist bdist_wheel
   
   # Upload the package to PyPI
   pipenv run twine upload --skip-existing --username consideratio dist/*
   

2. Push git commits and tags

   git push
   git push --tags
   

3. Build, run, and push a Docker image

   # Build and run
   docker build -t consideratio/discourse-sso-oidc-bridge:$TAG .
   docker run --rm -p 8080:8080 consideratio/discourse-sso-oidc-bridge:$TAG
   
   # Build and push
   docker build -t consideratio/discourse-sso-oidc-bridge:$TAG -t consideratio/discourse-sso-oidc-bridge:latest .
   docker push consideratio/discourse-sso-oidc-bridge:$TAG
   

Deployment notes

I have deployed this using a simpler not published Helm chart. I'm happy to open source this as well for a complete solution. But to avoid overworking something that few has interest for it in I'd appreciate if you showed interest in this by emailing me or opening an issue or similar.