feat: add graphql gateway

.env.example

@@ -1,2 +1,3 @@
 PORT=3000
+GATEWAY_PORT=3052
 SAMPLE_DATABASE_URL=postgres://user:secret@localhost:5432/postgres?schema=public

.nxignore

@@ -1 +1,2 @@
-schema.graphql
+schema.graphql
+supergraph.graphql

apps/api/src/app/app.module.ts

@@ -17,6 +17,7 @@ import { ApolloDriver } from '@nestjs/apollo'
             driver: ApolloDriver,
             autoSchemaFile: '../../schema.graphql',
             playground: false,
+            introspection: true,
             plugins: [ApolloServerPluginLandingPageLocalDefault()],
         }),
         SampleModule.forRoot({

apps/gateway/.eslintrc.json

@@ -0,0 +1,18 @@
+{
+  "extends": ["../../.eslintrc.json"],
+  "ignorePatterns": ["!**/*"],
+  "overrides": [
+    {
+      "files": ["*.ts", "*.tsx", "*.js", "*.jsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.ts", "*.tsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.js", "*.jsx"],
+      "rules": {}
+    }
+  ]
+}

apps/gateway/Dockerfile

@@ -0,0 +1,19 @@
+# Install dependencies only when needed
+FROM docker.io/node:lts-alpine as deps
+# Check https://github.com/nodejs/docker-node/tree/b4117f9333da4138b03a546ec926ef50a31506c3#nodealpine 
+# to understand why libc6-compat might be needed.
+RUN apk add --no-cache libc6-compat
+WORKDIR /usr/src/app
+COPY ./node_modules ./node_modules
+
+# Production image, copy all the files and run nest
+
+FROM docker.io/node:lts-alpine as runner
+RUN apk add --no-cache dumb-init
+ENV NODE_ENV production
+ENV PORT 3000
+WORKDIR /usr/src/app
+COPY --from=deps /usr/src/app/node_modules ./node_modules
+COPY dist/apps/gateway .
+EXPOSE 3000
+CMD ["dumb-init", "node", "main.js"]

apps/gateway/jest.config.ts

@@ -0,0 +1,15 @@
+/* eslint-disable */
+export default {
+    displayName: 'gateway',
+    preset: '../../jest.preset.js',
+    globals: {
+        'ts-jest': {
+            tsconfig: '<rootDir>/tsconfig.spec.json',
+        },
+    },
+    testEnvironment: 'node',
+    transform: {
+        '^.+\\.[tj]s$': 'ts-jest',
+    },
+    moduleFileExtensions: ['ts', 'js', 'html'],
+}

apps/gateway/project.json

@@ -0,0 +1,82 @@
+{
+  "name": "gateway",
+  "$schema": "../../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "apps/gateway/src",
+  "projectType": "application",
+  "targets": {
+    "build": {
+      "executor": "@nx/webpack:webpack",
+      "dependsOn": ["graphql:compose"],
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "target": "node",
+        "compiler": "tsc",
+        "outputPath": "dist/apps/gateway",
+        "main": "apps/gateway/src/main.ts",
+        "tsConfig": "apps/gateway/tsconfig.app.json",
+        "assets": ["apps/gateway/src/assets"]
+      },
+      "configurations": {
+        "production": {
+          "optimization": true,
+          "extractLicenses": true,
+          "inspect": false,
+          "fileReplacements": [
+            {
+              "replace": "apps/gateway/src/environments/environment.ts",
+              "with": "apps/gateway/src/environments/environment.prod.ts"
+            }
+          ]
+        }
+      }
+    },
+    "serve": {
+      "executor": "@nx/js:node",
+      "options": {
+        "buildTarget": "gateway:build"
+      },
+      "configurations": {
+        "production": {
+          "buildTarget": "gateway:build:production"
+        }
+      }
+    },
+    "lint": {
+      "executor": "@nx/linter:eslint",
+      "outputs": ["{options.outputFile}"],
+      "options": {
+        "lintFilePatterns": ["apps/gateway/**/*.ts"]
+      }
+    },
+    "test": {
+      "executor": "@nx/jest:jest",
+      "outputs": ["{workspaceRoot}/coverage/{projectRoot}"],
+      "options": {
+        "jestConfig": "apps/gateway/jest.config.ts",
+        "passWithNoTests": true
+      }
+    },
+    "graphql:compose": {
+      "executor": "schematics:graphql-gateway-compose"
+    },
+    "container": {
+      "executor": "@nx-tools/nx-container:build",
+      "dependsOn": ["build"],
+      "options": {
+        "engine": "docker",
+        "metadata": {
+          "images": ["nx/gateway"],
+          "load": true,
+          "tags": [
+            "type=schedule",
+            "type=ref,event=branch",
+            "type=ref,event=tag",
+            "type=ref,event=pr",
+            "type=sha,prefix=sha-"
+          ]
+        }
+      }
+    }
+  },
+  "tags": []
+}

apps/gateway/src/assets/supergraph.graphql

@@ -0,0 +1,38 @@
+schema
+  @core(feature: "https://specs.apollo.dev/core/v0.2"),
+  @core(feature: "https://specs.apollo.dev/join/v0.1", for: EXECUTION)
+{
+  query: Query
+}
+
+directive @core(as: String, feature: String!, for: core__Purpose) repeatable on SCHEMA
+
+directive @join__field(graph: join__Graph, provides: join__FieldSet, requires: join__FieldSet) on FIELD_DEFINITION
+
+directive @join__graph(name: String!, url: String!) on ENUM_VALUE
+
+directive @join__owner(graph: join__Graph!) on INTERFACE | OBJECT
+
+directive @join__type(graph: join__Graph!, key: join__FieldSet) repeatable on INTERFACE | OBJECT
+
+type Query {
+  samplePing: String! @join__field(graph: API)
+}
+
+enum core__Purpose {
+  """
+  `EXECUTION` features provide metadata necessary to for operation execution.
+  """
+  EXECUTION
+
+  """
+  `SECURITY` features provide metadata necessary to securely resolve fields.
+  """
+  SECURITY
+}
+
+scalar join__FieldSet
+
+enum join__Graph {
+  API @join__graph(name: "api" url: "http://localhost:3000/graphql")
+}

apps/gateway/src/environments/environment.prod.ts

@@ -0,0 +1,3 @@
+export const environment = {
+    production: true,
+}

apps/gateway/src/environments/environment.ts

@@ -0,0 +1,3 @@
+export const environment = {
+    production: false,
+}

apps/gateway/src/main.ts

@@ -0,0 +1,79 @@
+import { Logger } from '@nestjs/common'
+import { ApolloServer } from '@apollo/server'
+import { startStandaloneServer } from '@apollo/server/standalone'
+import { ApolloGateway } from '@apollo/gateway'
+import { readFileSync } from 'fs'
+const logger = new Logger('Application')
+
+//do something when app is closing
+process.on('exit', exitHandler.bind(null, { cleanup: true }))
+
+//catches ctrl+c event
+process.on('SIGINT', exitHandler.bind(null, { exit: true }))
+
+// catches "kill pid" (for example: nodemon restart)
+process.on('SIGUSR1', exitHandler.bind(null, { exit: true }))
+process.on('SIGUSR2', exitHandler.bind(null, { exit: true }))
+
+//catches uncaught exceptions
+process.on('uncaughtException', exitHandler.bind(null, { exit: true }))
+
+import env from 'env-var'
+import { join } from 'path'
+
+//do something when app is closing
+process.on('exit', exitHandler.bind(null, { cleanup: true }))
+
+//catches ctrl+c event
+process.on('SIGINT', exitHandler.bind(null, { exit: true }))
+
+// catches "kill pid" (for example: nodemon restart)
+process.on('SIGUSR1', exitHandler.bind(null, { exit: true }))
+process.on('SIGUSR2', exitHandler.bind(null, { exit: true }))
+
+//catches uncaught exceptions
+process.on('uncaughtException', exitHandler.bind(null, { exit: true }))
+
+async function bootstrap() {
+    const port = env.get('GATEWAY_PORT').default(3052).asPortNumber()
+
+    const server = new ApolloServer({
+        gateway: new ApolloGateway({
+            supergraphSdl: readFileSync(
+                join(__dirname, 'assets', 'supergraph.graphql'),
+            ).toString(),
+        }),
+    })
+
+    const { url } = await startStandaloneServer(server, {
+        listen: {
+            port,
+        },
+    })
+
+    logger.log(`Gateway ready at ${url}`)
+}
+
+try {
+    bootstrap().catch((err) => {
+        logger.error(err, err.stack)
+    })
+} catch (err) {
+    logger.error(err, err.stack)
+}
+
+function exitHandler(options, exitCode) {
+    if (options.cleanup) {
+        logger.log('exit: clean')
+    }
+    if (exitCode || exitCode === 0) {
+        if (exitCode !== 0) {
+            logger.error(exitCode, exitCode.stack)
+        } else {
+            logger.log(`exit: code - ${exitCode}`)
+        }
+    }
+    if (options.exit) {
+        process.exit()
+    }
+}

apps/gateway/supergraph.config.yaml

@@ -0,0 +1,5 @@
+subgraphs:
+  api:
+    routing_url: http://localhost:3000/graphql
+    schema:
+      file: ./../api/schema.graphql

apps/gateway/tsconfig.app.json

@@ -0,0 +1,12 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../dist/out-tsc",
+    "module": "commonjs",
+    "types": ["node"],
+    "emitDecoratorMetadata": true,
+    "target": "es2015"
+  },
+  "exclude": ["jest.config.ts", "**/*.spec.ts", "**/*.test.ts"],
+  "include": ["**/*.ts"]
+}

apps/gateway/tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "files": [],
+  "include": [],
+  "references": [
+    {
+      "path": "./tsconfig.app.json"
+    },
+    {
+      "path": "./tsconfig.spec.json"
+    }
+  ]
+}

apps/gateway/tsconfig.spec.json

@@ -0,0 +1,9 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../dist/out-tsc",
+    "module": "commonjs",
+    "types": ["jest", "node"]
+  },
+  "include": ["jest.config.ts", "**/*.test.ts", "**/*.spec.ts", "**/*.d.ts"]
+}

libs/schematics/executors.json

@@ -15,6 +15,11 @@
       "implementation": "./src/executors/prisma/migrate/executor",
       "schema": "./src/executors/prisma/migrate/schema.json",
       "description": "Run Prisma migrations"
+    },
+    "graphql-gateway-compose": {
+      "implementation": "./src/executors/graphql/gateway-compose/executor",
+      "schema": "./src/executors/graphql/gateway-compose/schema.json",
+      "description": "Run Apollo Rover supergraph composer"
     }
   }
 }

libs/schematics/src/executors/graphql/gateway-compose/executor.ts

@@ -0,0 +1,29 @@
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+import { GraphQLGatewayComposeExecutorSchema } from './schema'
+import { getExecOutput } from '@actions/exec'
+
+export default async function runExecutor(
+    options: GraphQLGatewayComposeExecutorSchema,
+) {
+    const args: string[] = []
+
+    options.config
+        ? args.push(`--config=${options.config}`)
+        : args.push(`--config=apps/gateway/supergraph.config.yaml`)
+
+    options.output
+        ? args.push(`-o=${options.output}`)
+        : args.push(`-o=apps/gateway/src/assets/supergraph.graphql`)
+
+    await getExecOutput(`rover supergraph compose`, args, {
+        ignoreReturnCode: true,
+    }).then((res) => {
+        if (res.stderr.length > 0 && res.exitCode != 0) {
+            throw new Error(`${res.stderr.trim() ?? 'unknown error'}`)
+        }
+    })
+
+    return {
+        success: true,
+    }
+}

libs/schematics/src/executors/graphql/gateway-compose/schema.d.ts

@@ -0,0 +1,4 @@
+export interface GraphQLGatewayComposeExecutorSchema {
+    config?: string
+    output?: string
+} // eslint-disable-line

libs/schematics/src/executors/graphql/gateway-compose/schema.json

@@ -0,0 +1,18 @@
+{
+  "$schema": "http://json-schema.org/schema",
+  "version": 2,
+  "title": "Build executor",
+  "description": "",
+  "type": "object",
+  "properties": {
+    "config": {
+      "type": "string",
+      "description": "The path to the supergraph config"
+    },
+    "output": {
+      "type": "string",
+      "description": "Output file to generate SDL"
+    }
+  },
+  "required": []
+}