AbsintheFederationExample

To start your Phoenix server:

• Run mix setup to install and setup dependencies
• Start Phoenix endpoint with mix phx.server or inside IEx with iex -S mix phx.server

Now you can visit localhost:4000 from your browser.

Ready to run in production? Please check our deployment guides.

Learn more

• Official website: https://www.phoenixframework.org/
• Guides: https://hexdocs.pm/phoenix/overview.html
• Docs: https://hexdocs.pm/phoenix
• Forum: https://elixirforum.com/c/phoenix-forum
• Source: https://github.com/phoenixframework/phoenix

Rover CLI

Rover is a CLI for managing and maintaining graphs.

https://www.apollographql.com/docs/rover/

brew install rover

Fetch GraphQL server's schema via introspection

rover graph introspect http://api.example.com/graphql > api.graphql
rover graph introspect http://api2.example.com/graphql > api2.graphql

Compose a federated supergraph schema from multiple subgraphs

Create a supergraph.yml config file which identifies the back end servers and graphs:

federation_version: 2
subgraphs:
  foo:
    routing_url: https://foo.example.com/
    schema:
      file: ./foo.graphql
  bar:
    routing_url: https://bar.example.com/
    schema:
      file: ./bar.graphql

Create output supergraph schema:

rover supergraph compose --config ./supergraph.yml > supergraph.graphql

Start Apollo Router

docker-compose up router

Query router

curl --request POST --header 'content-type: application/json' --url http://localhost:4000/graphql --data '{"query":"query { __typename }"}'
curl --request POST --header 'content-type: application/json' --url http://localhost:4000/graphql --data '{"query":"query { __schema { types {name} } }"}'
curl --request POST --header 'content-type: application/json' --url http://localhost:4000/graphql --data '{"query":"query { allLinks { id url description } }"}'

Links

• https://www.apollographql.com/docs/router/
• https://www.apollographql.com/docs/rover/commands/supergraphs/
• https://romankudryashov.com/blog/2022/07/apollo-router/