GraphQL Federation¶

const { ApolloServer, gql } = require("apollo-server-express");
const { buildFederatedSchema } = require("@apollo/federation");
const express = require('express');

const path = '/graphql';
const app = express();

const typeDefs = gql`

  scalar Integer

  extend type Query {
    extend_swapi_health: Health
  }

  extend type Planet @key(fields: "id") {
    id: ID! @external
    diameter: Integer @external
    mass: Int
    calculatedGravity: Integer @requires(fields: "diameter")
  }

  type Health {
    status: String
  }

  input Integer_Where {
    AND: [Integer_Where!]
    OR: [Integer_Where!]
    EQ: Integer
    NEQ: Integer
    LT: Integer
    LTE: Integer
    GT: Integer
    GTE: Integer
    IN: [Integer!]
    NIN: [Integer!]
  }

`

const resolvers = {
  Planet: {
    __resolveReference(reference) {
      return {
        ...reference,
        ...planetList.find(planet => planet.id === reference.id)
      };
    },
    calculatedGravity(reference) {
      console.log('Planet @key/id [' + reference.id + '] diameter [' + reference.diameter + ']');
      let planet = planetList.find(planet => planet.id === reference.id);
      console.log('Found planet its mass is [' + planet.mass + ']');
      // Clearly the wrong calc, its just to show calculated extension
      let gravity = reference.diameter * planet.mass * 100;
      console.log('Calculated gravity [' + this.gravity + ']');
      return gravity
    }
  },
  Query: {
    extend_swapi_health() {
      return { status: "OK"}
    }
  }
};

// Dummy Good to go always returns OK
app.get('/__gtg', function (req, res){
  res.setHeader('Content-Type', 'application/json');
  res.end(JSON.stringify({ gtg: "OK", message: "Mock SOaaS operating as expected" }));
});

// Dummy Health Check always returns OK, no dependencies/healthChecks
app.get('/__health', function (req, res){
  res.setHeader('Content-Type', 'application/json');
  res.end(JSON.stringify({
        status: "OK",
        id: `http://localhost:4006${server.graphqlPath}`,
        name: 'SOaaS Extended HealthCheck',
        type: 'graphql',
        healthChecks: []
      })
  )
});

const server = new ApolloServer({
  schema: buildFederatedSchema([
    {
      typeDefs,
      resolvers
    }
  ]),
  context: params => () => {
    console.log(params.req.body.query);
    console.log(params.req.body.variables);
    console.log(params.req.headers);
  }
});

server.applyMiddleware({app: app, path: path});

app.listen({ port: 4006 }, () => {
  console.log(`Server ready at http://localhost:4006${server.graphqlPath}`);
});

const planetList = [
  {
    id: "https://swapi.co/resource/planet/25",
    mass: 120
  },
  {
    id: "https://swapi.co/resource/planet/13",
    mass: 130
  }
];

const { ApolloServer, gql } = require("apollo-server-express");
const { buildFederatedSchema } = require("@apollo/federation");
const express = require('express');

const path = '/graphql';
const app = express();

const typeDefs = gql`

  extend type Query {
    organization_health: Health
  }

  type Organization @key(fields: "id") {
    id: ID!
    desc: String
    dateFounded: String
  }

  type Health {
    status: String
  }
`;

const resolvers = {
  Organization: {
    __resolveReference(reference) {
      return orgList.find(org => org.id === reference.id);
    }
  },
  Query: {
    organization(_, args) {
      if (args.id) {
        return orgList.filter(org => org.id === args.id);
      } else {
        return orgList;
      }
    },
    organization_health() {
      return { status: "OK"}
    }
  }
};

// Dummy Good to go always returns OK
app.get('/__gtg', function (req, res){
  res.setHeader('Content-Type', 'application/json');
  res.end(JSON.stringify({ gtg: "OK", message: "Mock SOaaS operating as expected" }));
});

// Dummy Health Check always returns OK, no dependencies/healthChecks
app.get('/__health', function (req, res){
  res.setHeader('Content-Type', 'application/json');
  res.end(JSON.stringify({
    status: "OK",
    id: `http://localhost:4007${server.graphqlPath}`,
    name: 'Organization GraphQL HealthCheck',
    type: 'graphql',
    healthChecks: []
  }))
});;

const server = new ApolloServer({
  schema: buildFederatedSchema([
    {
      typeDefs,
      resolvers
    }
  ]),
  context: params => () => {
    console.log(params.req.body.query);
    console.log(params.req.body.variables);
    console.log(params.req.headers);
  }
});

server.applyMiddleware({app: app, path: path});

app.listen({ port: 4007 }, () => {
  console.log(`Server ready at http://localhost:4007${server.graphqlPath}`);
});

const orgList = [
  {
    id: "https://swapi.co/resource/organization/1",
    desc: "The Resistance, also known as the Rebellion, was a private military force founded by General Leia Organa during the cold war between the New Republic and the First Order",
    dateFounded: "28 ABY"
  },
  {
    id: "https://swapi.co/resource/organization/2",
    desc: "The Galactic Empire (19 BBY–5 ABY), also known as the First Galactic Empire, the New Order, or simply the Empire, was the fascist galactic government that replaced the Galactic Republic in the aftermath of the Clone Wars",
    dateFounded: "19 BBY"
  }
];