@harmonyjs/controller-apollo-gateway/dist-src/index.js

Apollo Gateway controller for Harmony

import { ApolloGateway, RemoteGraphQLDataSource, } from '@apollo/gateway';
import { ApolloServer } from '@harmonyjs/apollo-fastify';
let gatewayReference = null;
let firstComposition = true;
function didUpdateComposition(callback, serviceNumber) {
    return function (services) {
        if (services.serviceDefinitions.length === serviceNumber && !firstComposition) {
            callback();
        }
        firstComposition = false;
    };
}
/*
 * The Apollo Controller exposes a GraphQL endpoint through an Apollo Server
 */
const ControllerApolloGateway = function (config) {
    return ({
        name: 'ControllerApolloGateway',
        async initialize({ server, logger }) {
            const { path, enablePlayground, services, authentication, gatewayConfig, apolloConfig, routeConfig, } = config;
            logger.info('Registering GraphQL Federation endpoint...');
            const gateway = gatewayReference || new ApolloGateway({
                ...(gatewayConfig || {}),
                serviceList: services,
                buildService({ url }) {
                    return new RemoteGraphQLDataSource({
                        url,
                        willSendRequest({ request, context }) {
                            if (context.headers) {
                                Object.keys(context.headers).forEach((header) => {
                                    request.http.headers.set(header, context.headers[header]);
                                });
                            }
                        },
                    });
                },
            });
            if (config.servicePoller) {
                if (!gatewayReference) {
                    logger.warn('Service polling enabled');
                    logger.warn('This is a development feature only. Do not use in production!');
                }
                firstComposition = true;
                gatewayReference = gateway;
                gatewayReference.experimental_pollInterval = 1000;
                gatewayReference.logger.disableAll(true);
                gatewayReference.startPollingServices();
                gatewayReference.experimental_didUpdateComposition = didUpdateComposition(config.servicePoller, config.services.length);
            }
            const apolloServer = new ApolloServer({
                ...(apolloConfig || {}),
                gateway,
                playground: !!enablePlayground,
                introspection: !!enablePlayground,
                context: ({ request }) => ({
                    headers: request.headers,
                }),
                subscriptions: false,
            });
            const routeOptions = { ...(routeConfig || {}) };
            if (authentication) {
                // @ts-ignore
                if (!server[authentication.validator]) {
                    logger.error('The provided authentication controller was not initialized');
                    logger.error(`Make sure the authentication controller ${authentication().name} is present in your controllers array and is before ${this.name}`);
                    throw new Error('Missing controller');
                }
                const preValidation = [];
                if (routeOptions.preValidation) {
                    if (Array.isArray(routeOptions.preValidation)) {
                        preValidation.push(...routeOptions.preValidation);
                    }
                    else {
                        preValidation.push(routeOptions.preValidation);
                    }
                }
                // @ts-ignore
                preValidation.push(server[authentication.validator].try);
                routeOptions.preValidation = preValidation;
            }
            await server.register(apolloServer.createHandler({
                path,
                cors: true,
                routeOptions,
            }));
            logger.info(`GraphQL endpoint at ${path}`);
            if (enablePlayground) {
                logger.info(`GraphQL playground at ${path}`);
            }
        },
    });
};
export default ControllerApolloGateway;