This sample app showcases federation and apollo gateway using the NestJS Framework. It decouples monolith graphs into seperated microservice graphs across various endpoints while utilizing a main entry point. The gateway also acts as an orchestration layer for authentication providers and for microservices.
The easiest way to decipher project layout is to look at the extension names of the files. Each component follows a pod-style layout where the functional areas belong to a folder structure.
.module - declare a high-level functional component
.resolver - indicates a graphql resolver
.service - indicates a service that interacts with graphql types.
.type - indicates a graphql object type
.entity - indicates a typeorm object, not to be confused with a graphql type.
This gateway and federation api serves two responsibilties.
-
Expose all microservices into a single graph
-
Pass a valid JWT token to microservices which require authentication.
See graphl-api draw.io diagram in this project. The gateway injects authorization tokens into outgoing requests if they exist. Receiving microservice can use this information to determine if a token is valid and has appropriate permissions tied to it in order to carry out a given request. This decouples the gateway architecture as being a lightweight pass-through medium.
$ npm install# development
$ npm run start
# watch mode
$ npm run start:dev
# production mode
$ npm run start:prod# unit tests
$ npm run test
# e2e tests
$ npm run test:e2e
# test coverage
$ npm run test:covThe following frameworks are components of this demo project.
TypeOrm framework is used as a relational db mapping tool to interface with databases> is a specification used to interact with apis in a flexible and powerful way.
Nest framework TypeScript starter repository.
Postgres database implementation for this project. Can be swapped out for another db. See typeorm.config.ts
N/A