Technical test

This repo was initiated during an hiring process as my answer to a technical test. It eveloved as a demonstrator for the BFF pattern and thin wrappers around spring-boot-starter-oauth2-resource-server and spring-boot-starter-oauth2-client I maintain on Github and publish on maven-central.

I was asked to produce an app related to the "Bao-Loc" problem: provide the distinct integers between 1 and 9 such as x1 + 13 * x2 / x3 + x4 + 12 * x5 - x6 - 11 + x7 * x8 / x9 - 10 = 66

Disclaimer

You should not copy code from this repo to answer a similar test: what is contained here is quite specific and you'll be instantly spotted as cheater.

Architecture

I propose:

• two options for OAuth2 security:
  • Angular application configured as an OAuth2 public client using angular-auth-oidc-client, where the browser application has access to OAuth2 tokens and authorizes its requests with JWTs.
  • Backend For Frontend pattern where the Angular application has not access to OAuth2 tokens. It is secured with sessions on the BFF. spring-cloud-gateway is configured as BFF (OAuth2 confidential client with TokenRelayfilter) and replaces session cookies with access token Authorization header before forwarding a request from the browser to resource server.
• a multi-module maven project in api folder:
  • built with Spring boot (web, JPA, validation, security, native, actuator)
  • documented with OpenAPI (Swagger)
  • backed by a relational database (Postgresql)
  • secured with OpenID: authentication enables the API to scope solutions to current user ones for all CRUD operations
• an Angular workspace in angular-ui folder, which contains:
  • 2 Angular applications: one for each security implementations
  • 2 API client libs generated from OpenAPI specs: one for gateway endpoints for BFF client (login options, logout and user-info endpoints), and another for solutions REST API
  • 2 common libraries for domain classes as well as shared components (reduce code duplication between the two applications to a very few code lines)
• Github CI / CD with deployment to a K8s managed cluster at OVH:
  • application using BFF is available from here
  • application configured as OAuth2 public client is available from there

Users registration and authentication is managed by a Keycloak instance deployed on the same K8s cluster.