Federation

A demonstration of microservices architecture using Apollo Federation.

Overview

This project implements a federated GraphQL architecture consisting of:

• Gateway: An Apollo Gateway that acts as the single entry point (Supergraph).
• Services: Independent services that compose the supergraph.
  • users: Manages user data and authentication.
• Clients: Frontend applications consuming the supergraph.
  • next: A Next.js application using Apollo Client with Automatic Persisted Queries (APQ).

Prerequisites

• Node.js
• Yarn

Installation

Install dependencies for all workspaces:

yarn install

Running the Project

Start the gateway and all services concurrently:

yarn dev

This command will:

1. Start the users subgraph.
2. Wait for the users service to be ready.
3. Start the gateway.
4. Start the next client.

Development

Commit Messages

This project uses Commitizen and Commitlint to ensure standardized commit messages.

To create a commit, stage your changes and run:

yarn commit

This will prompt you to fill in the required fields for a conventional commit message.

Alternatively, you can run Commitizen manually without installation via npx:

npx cz

Optional: Enforce conventional commits

To enforce conventional commits with Husky + commitlint:

yarn add -D @commitlint/cli @commitlint/config-conventional husky

Project Structure

• gateway/: Apollo Gateway service. Only for local development. Apollo Router will be used in production.
• services/: Directory containing subgraph services.
  • users/: NestJS-based users subgraph.
• clients/: Directory containing frontend applications.
  • next/: Next.js-based client application.
    • Uses @apollo/client for GraphQL communication.
    • Implements Automatic Persisted Queries (APQ) to reduce network overhead by sending query hashes instead of full query strings.

Minikube Workflow

Minikube is a tool that lets you run Kubernetes locally. It runs a single-node Kubernetes cluster on your personal computer (including Windows, macOS and Linux PCs) so that you can try out Kubernetes, or for daily development work.

Installation

You need to have Minikube and Docker installed.

• Docker: Please refer to the official Docker documentation for installation instructions.
• Minikube: Please refer to the official Minikube documentation for installation instructions.

Core Concepts

• Minikube: Creates and manages a local Kubernetes cluster on your machine. It sets up a virtual machine (or uses Docker) to run the cluster nodes.
• kubectl: The command-line tool used to communicate with the Kubernetes API. You use it to inspect, manage, and deploy resources to your cluster.
• Docker: The containerization platform. We use it here to build the container images for our services (users and gateway) that Minikube will run.

Steps

Follow these steps to deploy the services to a local Minikube cluster.

# Start Minikube
yarn minikube:start

# Build images and apply manifests
yarn deploy:up

# Check deployment status
yarn deploy:status

# Restart deployments
yarn deploy:restart

# View logs
yarn deploy:logs:users
yarn deploy:logs:gateway

# Get the Minikube URL for the gateway
yarn deploy:url

# Stop Minikube
yarn minikube:stop

Minikube Architecture (Hierarchy)

Cluster (Minikube)
└── Nodes (VMs/machines)
    └── Pods (smallest deployable units)
        └── Containers (your actual apps)