@wundergraph/cosmo-to-apollo-schema

Schema Loader

An Apollo Gateway plugin/helper that helps you to import your subgraphs directly from your Cosmo execution config and compose it into a supergraph sdl. It supports multiple import methods, including:

• Config File Watcher
• CDN Polling
• S3 Polling

Example Usage

import { ApolloGateway } from '@apollo/gateway';
import { ApolloServer } from '@apollo/server';
import { startStandaloneServer } from '@apollo/server/standalone';
// 1. Import Schema Loader
import { SchemaLoader } from '@wundergraph/cosmo-to-apollo-schema';

// 2. Configure with file, cdn or s3
const cosmoSchemaLoader = new SchemaLoader({
  filePath: './cosmo-config.json',
});

// 3. Pass it to the gateway subgraphSdl
const gateway = new ApolloGateway({
  supergraphSdl: cosmoSchemaLoader.supergraphSdl,
});

const server = new ApolloServer({
  gateway,
});

startStandaloneServer(server);

Loader Options

At least one of CDN, S3 or file path must be provided.

SchemaLoaderOptions {
  cdn?: CDNOptions;
  s3?: S3Options;
  filePath?: string;

  /*** Defaults to 15000 (15 seconds) */
  pollInterval?: number;
}

CDN

Poll the CDN for config file. The default interval is 15 seconds.

interface CDNOptions {
  endpoint?: string;
  token: string;
  signatureKey?: string;
}

endpoint: The url to the cdn. (default https://cosmo-cdn.wundergraph.com).

token: The token for your Federated Graph. You can generate one with the token create command.

signatureKey: The optional signature key is the one used to sign your config in your admission server.

Usage with Cosmo Cloud

Once you have a token generated using wgc router token create your_graph_name, you can use it in your environment file (.env) as shown below. This fetches from cosmo cloud as the default. Feel free to specify a signatureKey if you have configured admission.

import dotenv from 'dotenv';
import { ApolloGateway } from '@apollo/gateway';
import { ApolloServer } from '@apollo/server';
import { startStandaloneServer } from '@apollo/server/standalone';
import { SchemaLoader } from '@wundergraph/cosmo-to-apollo-schema';

dotenv.config();

// Fetches from Cosmo Cloud CDN by default
const cosmoSchemaLoader = new SchemaLoader({
  cdn: {
    // Token for your federated graph on cosmo.
    token: process.env.GRAPH_TOKEN,
  },
  pollInterval: 3000,
});

const gateway = new ApolloGateway({
  supergraphSdl: cosmoSchemaLoader.supergraphSdl,
});

const server = new ApolloServer({
  gateway,
});

startStandaloneServer(server).then(({ url }) => {
  console.log(`🚀  Server ready at ${url}`);
});

File

The plugin watches for any config file changes for the provided path and updates the sdl accordingly.

filePath: string;

S3

Poll your S3 bucket for the execution config. The default interval is 15 seconds.

interface S3Options {
  endpoint: string;
  port?: number;
  accessKey: string;
  secretKey: string;
  region?: Region;
  secure?: boolean;
  bucketName: string;
  objectPath: string;
}