feat(backend-common): add common code for service shell

plugins/catalog-backend/package.json

@@ -18,13 +18,10 @@
   "dependencies": {
     "@backstage/backend-common": "^0.1.1-alpha.7",
     "@backstage/catalog-model": "^0.1.1-alpha.7",
-    "compression": "^1.7.4",
-    "cors": "^2.8.5",
     "esm": "^3.2.25",
     "express": "^4.17.1",
     "express-promise-router": "^3.0.3",
     "fs-extra": "^9.0.0",
-    "helmet": "^3.22.0",
     "knex": "^0.21.1",
     "lodash": "^4.17.15",
     "morgan": "^1.10.0",

plugins/catalog-backend/src/service/standaloneApplication.ts

@@ -1,71 +0,0 @@
-/*
- * Copyright 2020 Spotify AB
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import {
-  errorHandler,
-  notFoundHandler,
-  requestLoggingHandler,
-} from '@backstage/backend-common';
-import compression from 'compression';
-import cors from 'cors';
-import express from 'express';
-import helmet from 'helmet';
-import { Logger } from 'winston';
-import { EntitiesCatalog, LocationsCatalog } from '../catalog';
-import { HigherOrderOperation } from '../ingestion';
-import { createRouter } from './router';
-
-export interface ApplicationOptions {
-  enableCors: boolean;
-  entitiesCatalog: EntitiesCatalog;
-  locationsCatalog?: LocationsCatalog;
-  higherOrderOperation?: HigherOrderOperation;
-  logger: Logger;
-}
-
-export async function createStandaloneApplication(
-  options: ApplicationOptions,
-): Promise<express.Application> {
-  const {
-    enableCors,
-    entitiesCatalog,
-    locationsCatalog,
-    higherOrderOperation,
-    logger,
-  } = options;
-  const app = express();
-
-  app.use(helmet());
-  if (enableCors) {
-    app.use(cors());
-  }
-  app.use(compression());
-  app.use(express.json());
-  app.use(requestLoggingHandler());
-  app.use(
-    '/catalog',
-    await createRouter({
-      entitiesCatalog,
-      locationsCatalog,
-      higherOrderOperation,
-      logger,
-    }),
-  );
-  app.use(notFoundHandler());
-  app.use(errorHandler());
-
-  return app;
-}

plugins/catalog-backend/src/service/standaloneServer.ts

@@ -14,13 +14,15 @@
  * limitations under the License.
  */
 
+import { createServiceBuilder } from '@backstage/backend-common';
 import { Server } from 'http';
 import { Logger } from 'winston';
+import { HigherOrderOperations } from '..';
 import { DatabaseEntitiesCatalog } from '../catalog/DatabaseEntitiesCatalog';
 import { DatabaseLocationsCatalog } from '../catalog/DatabaseLocationsCatalog';
 import { DatabaseManager } from '../database/DatabaseManager';
-import { HigherOrderOperations, LocationReaders } from '../ingestion';
-import { createStandaloneApplication } from './standaloneApplication';
+import { createRouter } from './router';
+import { LocationReaders } from '../ingestion';
 
 export interface ServerOptions {
   port: number;
@@ -33,11 +35,11 @@ export async function startStandaloneServer(
 ): Promise<Server> {
   const logger = options.logger.child({ service: 'catalog-backend' });
 
+  logger.debug('Creating application...');
   const db = await DatabaseManager.createInMemoryDatabase(logger);
-
   const entitiesCatalog = new DatabaseEntitiesCatalog(db);
   const locationsCatalog = new DatabaseLocationsCatalog(db);
-  const locationReader = new LocationReaders(options.logger);
+  const locationReader = new LocationReaders();
   const higherOrderOperation = new HigherOrderOperations(
     entitiesCatalog,
     locationsCatalog,
@@ -45,25 +47,18 @@ export async function startStandaloneServer(
     logger,
   );
 
-  logger.debug('Creating application...');
-  const app = await createStandaloneApplication({
-    enableCors: options.enableCors,
+  logger.debug('Starting application server...');
+  const router = await createRouter({
     entitiesCatalog,
     locationsCatalog,
     higherOrderOperation,
     logger,
   });
-
-  logger.debug('Starting application server...');
-  return await new Promise((resolve, reject) => {
-    const server = app.listen(options.port, (err?: Error) => {
-      if (err) {
-        reject(err);
-        return;
-      }
-
-      logger.info(`Listening on port ${options.port}`);
-      resolve(server);
-    });
+  const service = createServiceBuilder()
+    .enableCors({ origin: 'http://localhost:3000' })
+    .addRouter('/catalog', router);
+  return await service.start().catch(err => {
+    logger.error(err);
+    process.exit(1);
   });
 }