This repository demonstrates a GraphQL Federation setup using Apollo Router and three distinct subgraphs: Product, Review, and Shipping. It showcases how to combine multiple independent GraphQL services into a single, unified supergraph.

The project consists of the following components:

• Apollo Router: The entry point for all GraphQL queries. It orchestrates requests across the different subgraphs.
• Product Service: A subgraph responsible for product-related data (e.g., id, name, price, weight).
• Review Service: A subgraph handling product reviews (e.g., id, body).
• Shipping Service: A subgraph providing shipping information, including estimated delivery times, which depends on data from the Product service.

To get this project up and running, follow these steps:

• Docker (Docker Compose included)
• Go (for building the Go services, though Docker handles this)

The supergraph schema is composed using the Apollo Rover CLI. This step generates the supergraph.graphql file that the Apollo Router uses.

make compose-supergraph

This command will:

• Pull the worksome/rover:latest Docker image if not already present.
• Run the Rover CLI in a Docker container to compose the supergraph based on router/supergraph-config.yaml.
• Output the combined schema to router/supergraph.graphql.

Once the supergraph is composed, you can start all services using Docker Compose:

make start

This command will:

• Build the Docker images for the product, review, and shipping services.
• Start all four services (router, product, review, shipping) in detached mode.

To stop everything:

make stop

This command simply stop all docker containers.

• Product Service: Exposes product details.
  • Endpoint: http://localhost:8081/query
• Review Service: Manages product reviews.
  • Endpoint: http://localhost:8082/query
• Shipping Service: Provides shipping estimates.
  • Endpoint: http://localhost:8083/query

Once all services are running, the GraphQL supergraph endpoint will be available at:

http://localhost:4000/

You can use a GraphQL client (like Apollo Sandbox, GraphQL Playground, or Insomnia) to send queries to this endpoint and interact with the federated graph.

Example Query:

query GetProductList {
  productList {
    id
    name
    price
    weight
    reviews {
      id
      body
    }
    estimatedDeliveryTime
  }
}

Alternatively, you can access http://localhost:4000/graphql to enter the router sandbox mode, where instrospection can be done, and sample queries can be constructed more easily before running.