williamhaw / federation-demo-caliban

federation-demo-caliban

This repository reimplements Apollo's federation-demo using Scala and Caliban.

Contents

Service	Api	Server
Accounts	AccountsApi	AccountsServer
Reviews	ReviewsApi	ReviewsServer
Products	ProductsApi	ProductsServer
Inventory	InventoryApi	InventoryServer

Requirements

• sbt > 1.x
• recent version of npm and node

Setup and Run

1. Run all servers by starting the sbt shell:

    > sbt

2. Inside the sbt shell, run:

   ...
   [info] started sbt server
   sbt:federation-demo-caliban> run AllServers
   

3. In the repository root, run

   > npm install

4. Then run

   > npm run start-gateway

5. Navigate to http://localhost:4000 in your preferred browser.
6. To observe traces with OpenTelemetry, run Jaeger with:

   docker run -d --name jaeger \
    -e COLLECTOR_ZIPKIN_HOST_PORT=:9411 \
    -p 5775:5775/udp \
    -p 6831:6831/udp \
    -p 6832:6832/udp \
    -p 5778:5778 \
    -p 16686:16686 \
    -p 14250:14250 \
    -p 14268:14268 \
    -p 14269:14269 \
    -p 9411:9411 \
    jaegertracing/all-in-one:1.29

   Then navigate to http://localhost:16686/. Run queries and observe the traces being logged.
7. Close both gateway and services by hitting Ctrl-C.

Example Queries

query ExampleQuery {
  me {
    id
    name
    username
    reviews {
      body
      product {
        name
      }
    }
  }
  topProducts(first: 3) {
    upc
    name
    price
    weight
    inStock
    shippingEstimate
    reviews {
      body
      author {
        name
        username
      }
    }
  }
}

Notes

• AccountsServer uses Play to serve GraphQL Playground and run the GQL interpreter. The other servers use Akka HTTP directly.