Local Composition

You may want to generate a federated schema for local development without making any changes to your Configured Schema in the Inigo cloud. Inigo offers two ways to do this:

1. Use inigo compose with a local Gateway configuration
2. Use inigo compose with a LocalCompose configuration

In either case, the entire federated schema definition will be printed out, and if there are errors, the errors will be printed out instead of a federated schema.

Local Gateway Approach

By using a Gateway configuration that you only use for local development, you can easily reference all of your local supergraph schema files and compose them together into a federated graph as shown in example 2.

gateway.yaml

kind: Gateway
name: apollo-gateway-fed-2-demo
label: dev
spec:
  composition: ApolloFederation_v2
  services:
    - name: accounts
      url: "http://localhost:4001/graphql"
      schema_files:
        - ../services/accounts/schema.graphql
    - name: reviews
      url: "http://localhost:4002/graphql"
      schema_files:
        - ../services/reviews/schema.graphql
    - name: products
      url: "http://localhost:4003/graphql"
      schema_files:
        - ../services/products/schema.graphql
    - name: inventory
      url: "http://localhost:4004/graphql"
      schema_files:
        - ../services/inventory/schema.graphql

Example 1. A Local Gateway configuration referencing local subgraph schema files.

Creating a composed schema from a local Gateway configuration file is done using the inigo compose command as such:

inigo compose local-gateway.yaml > supergraph.graphql

LocalCompose Approach

If you need more flexibility on how you locally compose your subgraphs, LocalCompose makes this possible. For example, you may not have a copy on your local machine of all of the peer subgraphs that you would need to compose using a Gateway configuration.

Inside the LocalCompose configuration, you can supply the federated graph to use as a base and the subgraphs to override. For each subgraph override, you can specify where to get the schema for that subgraph. Schema source can come from a local schema file, fetched via a URL endpoint, or fetched from the Inigo cloud.

IMPORTANT

In order to run inigo compose with the LocalCompose, a composed schema must be available in your Schema Repository.

note

LocalCompose does not have side effects in the Inigo cloud when inigo compose is run

In Example 2, each subgraph fetches his or her schema using a different source. New subgraphs can also be added by providing a new subgraph name that is not currently part of the federated schema.

local.compose.yaml

kind: LocalCompose
name: federated_service_name (1)
spec:
  services:
    - name: service_one (2)
      url: http://service_one:8000/query
      source:
        schema_files:
          - ../graphql/service_one.graphql

    - name: service_two (3)
      url: http://service_two:8000/query
      source:
        ref: service_two:dev

    - name: service_three (4)
      url: http://service_three:8000/query
      source:
        sdl_url: http://service_three:8000/query
        sdl_headers:
          - name: Authorization
            value: Bearer <token>

    - name: service_new (5)
      url: http://service_new:8000/query
      source:
        schema_files:
          - ../graphql/new.graphql

Example 2. LocalCompose configuration overriding subgraph configurations.

The following list references the numbered labels in Example 2 and provides further explanation:

1. The federated_service_name Gateway name that is used for the federated schema, and the federated schema should already be published using inigo publish
2. Override the service_one subgraph with a local schema file.
3. Override the service_two subgraph with a service_two:dev Subgraph
4. Override the service_three subgraph with a URL referencing an SDL
5. Add a new service_new to be locally composed with the others

Creating a composed schema from a LocalCompose configuration file is done using the inigo compose command as such:

inigo compose local-compose.yaml > supergraph.graphql