# nodejs-graphql-microservices

**Repository Path**: mirrors_KieranLafferty/nodejs-graphql-microservices

## Basic Information

- **Project Name**: nodejs-graphql-microservices
- **Description**: GraphQL API with gRPC back-end microservices written in Node.js. Used for learning/trial & boilerplate purposes only.
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-12-20
- **Last Updated**: 2026-05-10

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Node.js GraphQL API + gRPC microservices

This project is a [monorepo](https://gomonorepo.org/) containing a [GraphQL](https://graphql.org/) API with [gRPC](https://grpc.io/) back-end microservices all written in Node.js. This project is mainly used for learning/trial and boilerplate purposes only.

## Graph Model

When creating GraphQL APIs, one must understand what [Graph Theory](https://en.wikipedia.org/wiki/Graph_theory) and Graph Data Modelling are. One must also [think in graphs](https://graphql.org/learn/thinking-in-graphs/) as per the GraphQL specification recommends. A diagram of the graph data model is shown below.

![Graph Model](https://raw.githubusercontent.com/benjsicam/nodejs-graphql-microservices/master/docs/img/graph-model.png)

### Explanation

1. Users can write both posts and comments therefore, users are authors posts and comments.
2. Posts are authored by users and comments can be linked/submitted for them.
3. Comments are authored by users and are linked/submitted to posts.

## Architecture Overview
 
The GraphQL API acts as a gateway/proxy for the different microservices it exposes. The resolvers of the GraphQL API make calls to the gRPC microservices through client-server communication. The services and the data interchange are defined using [Protocol Buffers](https://developers.google.com/protocol-buffers/). The gRPC microservices handle and fulfill the requests whether they are database or storage operations or any other internal or external calls.

### Diagram

A diagram of the architecture is shown below.

![Architecture Diagram](https://raw.githubusercontent.com/benjsicam/nodejs-graphql-microservices/master/docs/img/archi-diagram.png)

This architecture implements the following Microservice Design Patterns:

1. [Microservice Architecture](https://microservices.io/patterns/microservices.html)
2. [Subdomain Decomposition](https://microservices.io/patterns/decomposition/decompose-by-subdomain.html)
3. [Externalized Configuration](https://microservices.io/patterns/externalized-configuration.html)
4. [Remote Procedure Invocation](https://microservices.io/patterns/communication-style/rpi.html)
5. [API Gateway](https://microservices.io/patterns/apigateway.html)
6. [Database per Service](https://microservices.io/patterns/data/database-per-service.html)

## Layers

### API Layer

[GraphQL](https://graphql.org/) acts as the API Layer for the architecture. It takes care of listening for client requests and calling the appropriate back-end microservice to fulfill them.

### Microservice Layer

[MaliJS](https://mali.js.org/) was chosen as the framework to do the gRPC microservices. [Protocol buffers](https://developers.google.com/protocol-buffers/) was used as the data interchange format between the client (GraphQL API) and the server (gRPC microservices).

### Persistence Layer

PostgreSQL is used as the database and [Sequelize](https://sequelize.org) is used as the Object-Relational Mapper (ORM).

## Deployment

Deployment is done with containers in mind. A Docker Compose file along with Dockerfiles for each project are given to run the whole thing on any machine. It's recommended to use [Kubernetes](https://kubernetes.io/) for deploying microservices at scale in production. [Istio](https://istio.io/) takes care of service discovery, distributed tracing and other observability requirements.

## How to Run

### Pre-requisites

You must install the following on your local machine:

1. Node.js (v12.x recommended)
2. Docker
3. Docker Compose
4. PostgreSQL Client (libpq as required by [pg-native](https://www.npmjs.com/package/pg-native#install))

### Running

1. On the Terminal, go into the project's root folder (`cd /project/root/folder`) and execute `npm start`. The start script will install all npm dependencies for all projects, lint the code, transpile the code, build the artifacts (Docker images) and run all of them via `docker-compose`.

2. Once the start script is done, the GraphQL Playground will be running on [http://localhost:3000](http://localhost:3000)

### Video Demo (old)

[![GraphQL + gRPC Microservices](https://raw.githubusercontent.com/benjsicam/nodejs-graphql-microservices/master/docs/img/vid-preview.jpg)](https://youtu.be/SuH2K92FOaE)