feat: ✨ Federated gateway

.vscode/settings.json

@@ -1,5 +1,6 @@
 {
   "cSpell.words": [
-    "nestjs"
+    "nestjs",
+    "supergraph"
   ]
 }

apps/gateway/src/app/app.module.ts

@@ -1,10 +1,23 @@
+import { IntrospectAndCompose } from '@apollo/gateway';
+import { ApolloGatewayDriver, ApolloGatewayDriverConfig } from '@nestjs/apollo';
 import { Module } from '@nestjs/common';
+import { GraphQLModule } from '@nestjs/graphql';
+import { subgraphsConfig } from '@graphql-federation-workspace/applications-config';
 
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
 
 @Module({
-  imports: [],
+  imports: [
+    GraphQLModule.forRoot<ApolloGatewayDriverConfig>({
+      driver: ApolloGatewayDriver,
+      gateway: {
+        supergraphSdl: new IntrospectAndCompose({
+          subgraphs: subgraphsConfig,
+        }),
+      },
+    }),
+  ],
   controllers: [AppController],
   providers: [AppService],
 })

apps/gateway/src/main.ts

@@ -14,9 +14,7 @@ async function bootstrap() {
   const port = gatewayConfig.port;
 
   await app.listen(port);
-  Logger.log(
-    `🚀 Application is running on: http://${gatewayConfig.host}:${port}`
-  );
+  Logger.log(`🚀 Application is running on: ${gatewayConfig.host}:${port}`);
 }
 
 bootstrap();

apps/users-application/src/main.ts

@@ -14,9 +14,7 @@ async function bootstrap() {
   const port = userSubGraph.port;
 
   await app.listen(port);
-  Logger.log(
-    `🚀 Application is running on: http://${userSubGraph.host}:${port}`
-  );
+  Logger.log(`🚀 Application is running on: ${userSubGraph.host}:${port}`);
 }
 
 bootstrap();

libs/application-config/src/index.ts

@@ -1 +1,2 @@
 export * from './lib/applications-config';
+export * from './lib/subgraphs-config';

libs/application-config/src/lib/applications-config.ts

@@ -1,6 +1,7 @@
 interface ApplicationConfig {
   host: string;
   port: string;
+  name: string;
 }
 
 const DEFAULT_HOST = 'localhost';
@@ -15,15 +16,18 @@ const DEFAULT_PORT = {
 export const gatewayConfig: ApplicationConfig = {
   host: process.env['GATEWAY_HOST'] ?? DEFAULT_HOST,
   port: process.env['GATEWAY_PORT'] ?? DEFAULT_PORT.gateway,
+  name: 'gateway',
 };
 
 // Graphql
 export const userSubGraph: ApplicationConfig = {
   host: process.env['USER_HOST'] ?? DEFAULT_HOST,
   port: process.env['USER_PORT'] ?? DEFAULT_PORT.user,
+  name: 'user',
 };
 
 export const taskSubGraph: ApplicationConfig = {
   host: process.env['TASK_HOST'] ?? DEFAULT_HOST,
   port: process.env['TASK_PORT'] ?? DEFAULT_PORT.task,
+  name: 'task',
 };

libs/application-config/src/lib/subgraphs-config.ts

@@ -0,0 +1,10 @@
+import { ServiceEndpointDefinition } from '@apollo/gateway';
+
+import { userSubGraph } from './applications-config';
+
+export const subgraphsConfig: ServiceEndpointDefinition[] = [
+  {
+    name: userSubGraph.name,
+    url: `${userSubGraph.host}:${userSubGraph.port}/graphql`,
+  },
+];