Implement SSO - POC/MVP

[otarza]

Followup on #13

Prepare SSO Drupal instance

• Setup new Docker containers for SSO;
• Setup initial SSO Drupal installation;
• Install simple_oauth module;
• Generate certificates for simple_oauth using omgwtfssl docker container;
• Configure simple_oauth global settings;
• Add new Drupal instance to Falcon codebase;
• Create new simple_oauth client config entity;
• Test auth token generation according to simple_oauth docs.
• Create simple_oauth_sso module to support SSO features.
• Implement auth route and a controller.
• Implement login form which will authenticate user against simple_oauth;
• Implement login.js custom library which will handle login form;
• Implement redirect after authentication;
• Write documentation on using simple_oauth_sso with simple_oauth.
• Configure SSO instance for platform.sh;

Implement Drupal 8 sso_client module for backend services

• Implement custom AuthenticationProvider;
• Receive auth token from API Bus;
• Make request to SSO and try to authenticate using auth token;
• Create "proxy" user if it's new;
• Store session for the user with same expiration and validation details provided from SSO.
• If received request with already authenticated valid token and session is not expired yet, authenticate user;

Implement standalone javascript SSO module

• Implement a login button which will take user to SSO auth route with proper redirect back url in query parameter.
• Implement a login handler for when user gets back with auth token in query parameter;
• Store auth token, refresh token and expire date in local storage.
• Implement auth client which will send auth token to API Bus and gets authenticated user data as a response;
• Store user data in local storage;
• Implement token validation handler, so if it's not valid or expired, user should be redirected to SSO auth route;

Prepare API Bus for handling auth requests

• get to know to API Bus and implement proper way to handle and pass requests from frontend to backend services;