Apollo GraphQL Federation

Apollo GraphQL Federation demo in multiple languages.

Federated Service Demo

This project is used to demo joing Graph layers from various languages and libraries.

graph TD
  Client(Client)--request-->Gateway(Data Graph Gateway - Node)
  Gateway-->Customers(Customers - Node)
  Customers-->Gateway
  Gateway-->Orders(Orders - Node)
  Orders-->Gateway
  Gateway-->Products(Products - Node)
  Products-->Gateway
  Gateway-->Reviews(Reviews - Ruby)
  Reviews-->Gateway
  Gateway--response-->Client

Installation

Make sure you are using the latest Node LTS nvm use
Install Dependencies yarn install
Start Federated Services yarn start-services
Start Gateway (Data Graph) yarn start-gateway
Start Apollo Client Next.js App yarn start-client
Visit http://localhost:4000 in browser to launch GraphQL Playground (Graphiql)

tip: if you need to kill any tcp ports lsof -ti tcp:<PORT> | xargs kill or sudo kill -9 $(lsof -i :<PORT> -t)

Queries and Mutations

Example Queries

Refer to DOCS inside Graphiql for more information on queries and muations.

allOrders: Retrieve all orders.

query {
  allOrders {
    id
    financialStatus
    fulfillmentStatus
    customer {
      id
      firstName
      lastName
      email
    }
  }
}

customerByEmail: Retrieves customer information by email including all orders placed by customer.

query {
  customerByEmail(email: "janedoe@example.com") {
    firstName
    lastName
    email
    orders {
      id
      financialStatus
      fulfillmentStatus
    }
  }
}

Example Mutations

deleteOrder: Deletes one order.

mutation {
  deleteOrder(id: "order-2") {
    id
    financialStatus
    fulfillmentStatus
    customer {
      id
      firstName
      lastName
      email
    }
  }
}

Apollo Persisted Queries

Apollo servers features automatic persisted queries. Apollo Client will make a GET request utalizing a SHA256 hash to reference a query. If that query is not in memory on Apollo Server, it will respond with "code": "PERSISTED_QUERY_NOT_FOUND", subsequently Apollo Client will then make a standard GraphQL POST request to Apollo Server with the same hash so that Apollo Server can save the query in memory.

Redis, Memcached, or any standard key value store can be used to persist the data on your Apollo Server. By default Apollo Server will utalize in-memory cache.

Advatages include improved network performance by utalizing HTTP caching to reduce query string size on GET requests.

Sample query string parameters sent on GET request

{
  "persistedQuery": {
    "version":1,"sha256Hash":"3652ff3ed3e55b94ab31a26a3c65221f30df1432e80d6ebbd3cabf730eac3b94"
  }
}

Apollo Graph Manager

Apollo Graph Manager (formerly Apollo Engine) is a cloud service that helps you manage, validate, and secure your organization's data graph.

graph LR
  A(Data Graph Gateway)-->B(Apollo Graph Manager)
  B-->A

Publish Schema to Graph Manager

note: use npx if not installed globally, npm install -g apollo

Run all services yarn start-services and gateway yarn start-gateway
Login or create an account Apollo Data Graph Manager.
Update ENGINE_API_KEY in .env file.
Push schema to Data Graph Manager from root apollo service:push --endpoint=http://localhost:4000
Register each federated services apollo service:push --serviceName="customers" --serviceURL="http://customers-graphql.svc.cluster.local:4001/" --endpoint="http://localhost:4001/"
List all federated services: apollo service:list

TODO: connect to CI/CD process

tsoisauce / apollo-graphql-federation