Merge pull request #686 from spotify/freben/inventory-again

Make the inventory backend standalone runnable

packages/backend-common/README.md

@@ -24,8 +24,8 @@ import {
 const app = express();
 app.use(requestLoggingHandler());
 app.use('/home', myHomeRouter);
-app.use(errorHandler());
 app.use(notFoundHandler());
+app.use(errorHandler());
 
 app.listen(PORT, () => {
   getRootLogger().info(`Listening on port ${PORT}`);

packages/backend/src/index.ts

@@ -28,32 +28,38 @@ import {
   notFoundHandler,
   requestLoggingHandler,
 } from '@backstage/backend-common';
-import { router as inventoryRouter } from '@backstage/plugin-inventory-backend';
+import { createRouter as inventoryRouter } from '@backstage/plugin-inventory-backend';
+import { createScaffolder } from '@backstage/plugin-scaffolder-backend';
 import compression from 'compression';
 import cors from 'cors';
 import express from 'express';
 import helmet from 'helmet';
 import { testRouter } from './test';
-import { createScaffolder } from '@backstage/plugin-scaffolder-backend';
 
 const DEFAULT_PORT = 7000;
-
 const PORT = parseInt(process.env.PORT ?? '', 10) || DEFAULT_PORT;
-const app = express();
+const logger = getRootLogger().child({ type: 'plugin' });
 
-const scaffolder = createScaffolder();
+async function main() {
+  const inventory = await inventoryRouter({ logger });
+  const scaffolder = createScaffolder();
 
-app.use(helmet());
-app.use(cors());
-app.use(compression());
-app.use(express.json());
-app.use(requestLoggingHandler());
-app.use('/test', testRouter);
-app.use('/inventory', inventoryRouter);
-app.use('/scaffolder', scaffolder);
-app.use(errorHandler());
-app.use(notFoundHandler());
+  const app = express();
 
-app.listen(PORT, () => {
-  getRootLogger().info(`Listening on port ${PORT}`);
-});
+  app.use(helmet());
+  app.use(cors());
+  app.use(compression());
+  app.use(express.json());
+  app.use(requestLoggingHandler());
+  app.use('/test', testRouter);
+  app.use('/inventory', inventory);
+  app.use('/scaffolder', scaffolder);
+  app.use(notFoundHandler());
+  app.use(errorHandler());
+
+  app.listen(PORT, () => {
+    getRootLogger().info(`Listening on port ${PORT}`);
+  });
+}
+
+main();

plugins/inventory-backend/package.json

@@ -5,18 +5,30 @@
   "license": "Apache-2.0",
   "private": true,
   "scripts": {
+    "start": "tsc-watch --onFirstSuccess \"nodemon dist/run.js\"",
     "build": "tsc",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test",
     "clean": "backstage-cli clean"
   },
   "devDependencies": {
-    "@backstage/cli": "^0.1.1-alpha.4"
+    "@backstage/cli": "^0.1.1-alpha.4",
+    "jest-fetch-mock": "^3.0.3",
+    "tsc-watch": "^4.2.3"
   },
   "dependencies": {
-    "express": "^4.17.1"
+    "@backstage/backend-common": "0.1.1-alpha.4",
+    "compression": "^1.7.4",
+    "cors": "^2.8.5",
+    "express": "^4.17.1",
+    "helmet": "^3.22.0",
+    "morgan": "^1.10.0",
+    "winston": "^3.2.1"
   },
   "files": [
     "dist"
-  ]
+  ],
+  "nodemonConfig": {
+    "watch": "./dist"
+  }
 }

plugins/inventory-backend/src/index.ts

@@ -14,4 +14,4 @@
  * limitations under the License.
  */
 
-export { router } from './plugin';
+export * from './service/router';

plugins/inventory-backend/src/inventory/AggregatorInventory.ts

@@ -0,0 +1,35 @@
+/*
+ * 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 { Component, Inventory } from './types';
+
+export class AggregatorInventory implements Inventory {
+  inventories: Inventory[] = [];
+
+  list(): Promise<Array<Component>> {
+    return Promise.all(this.inventories.map(i => i.list())).then(lists =>
+      lists.flat(),
+    );
+  }
+
+  item(id: string): Promise<Component | undefined> {
+    return this.list().then(items => items.find(i => i.id === id));
+  }
+
+  enlist(inventory: Inventory) {
+    this.inventories.push(inventory);
+  }
+}

plugins/inventory-backend/src/inventory/StaticInventory.ts

@@ -0,0 +1,29 @@
+/*
+ * 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 { Component, Inventory } from './types';
+
+export class StaticInventory implements Inventory {
+  constructor(private components: Component[]) {}
+
+  list(): Promise<Array<Component>> {
+    return Promise.resolve([...this.components]);
+  }
+
+  item(id: string): Promise<Component | undefined> {
+    return this.list().then(items => items.find(i => i.id === id));
+  }
+}

plugins/inventory-backend/src/inventory/index.ts

@@ -0,0 +1,19 @@
+/*
+ * 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.
+ */
+
+export * from './AggregatorInventory';
+export * from './StaticInventory';
+export * from './types';

plugins/inventory-backend/src/inventory/types.ts

@@ -14,17 +14,11 @@
  * limitations under the License.
  */
 
-import express from 'express';
+export type Component = {
+  id: string;
+};
 
-export const router = express.Router();
-
-router.get('/', async (_, res) => {
-  res
-    .status(200)
-    .send([
-      { id: 'component1' },
-      { id: 'component2' },
-      { id: 'component3' },
-      { id: 'component4' },
-    ]);
-});
+export type Inventory = {
+  list: () => Promise<Component[]>;
+  item: (id: string) => Promise<Component | undefined>;
+};

plugins/inventory-backend/src/run.ts

@@ -0,0 +1,34 @@
+/*
+ * 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 { getRootLogger } from '@backstage/backend-common';
+import { startServer } from './service/server';
+
+startServer({
+  port: process.env.PLUGIN_PORT ? Number(process.env.PLUGIN_PORT) : 3003,
+  enableCors: process.env.PLUGIN_CORS
+    ? Boolean(process.env.PLUGIN_CORS)
+    : false,
+  logger: getRootLogger(),
+}).catch(err => {
+  getRootLogger().error(err);
+  process.exit(1);
+});
+
+process.on('SIGINT', () => {
+  getRootLogger().info('CTRL+C pressed; exiting.');
+  process.exit(0);
+});

plugins/inventory-backend/src/service/application.ts

@@ -0,0 +1,51 @@
+/*
+ * 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 { createRouter } from './router';
+
+export interface ApplicationOptions {
+  enableCors: boolean;
+  logger: Logger;
+}
+
+export async function createApplication(
+  options: ApplicationOptions,
+): Promise<express.Application> {
+  const app = express();
+
+  app.use(helmet());
+  if (options.enableCors) {
+    app.use(cors());
+  }
+  app.use(compression());
+  app.use(express.json());
+  app.use(requestLoggingHandler());
+  app.use('/', await createRouter({ logger: options.logger }));
+  app.use(notFoundHandler());
+  app.use(errorHandler());
+
+  return app;
+}

plugins/inventory-backend/src/service/router.ts

@@ -0,0 +1,61 @@
+/*
+ * 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 express from 'express';
+import { Logger } from 'winston';
+import { AggregatorInventory, StaticInventory } from '../inventory';
+
+export interface RouterOptions {
+  logger: Logger;
+}
+
+export async function createRouter(
+  options: RouterOptions,
+): Promise<express.Router> {
+  const logger = options.logger.child({ plugin: 'inventory' });
+
+  const inventory = new AggregatorInventory();
+  inventory.enlist(
+    new StaticInventory([
+      { id: 'component1' },
+      { id: 'component2' },
+      { id: 'component3' },
+      { id: 'component4' },
+    ]),
+  );
+
+  const router = express.Router();
+  router
+    .get('/', async (req, res) => {
+      const components = await inventory.list();
+      res.status(200).send(components);
+    })
+    .get('/:id', async (req, res) => {
+      const { id } = req.params;
+      const component = await inventory.item(id);
+      if (component) {
+        res.status(200).send(component);
+      } else {
+        res.status(404).send();
+      }
+    });
+
+  const app = express();
+  app.set('logger', logger);
+  app.use('/', router);
+
+  return app;
+}

plugins/inventory-backend/src/service/server.ts

@@ -0,0 +1,48 @@
+/*
+ * 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 { Server } from 'http';
+import { Logger } from 'winston';
+import { createApplication } from './application';
+
+export interface ServerOptions {
+  port: number;
+  enableCors: boolean;
+  logger: Logger;
+}
+
+export async function startServer(options: ServerOptions): Promise<Server> {
+  const logger = options.logger.child({ service: 'inventory-backend' });
+
+  logger.debug('Creating application...');
+  const app = await createApplication({
+    enableCors: options.enableCors,
+    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);
+    });
+  });
+}

plugins/inventory-backend/src/setupTests.ts

@@ -13,3 +13,5 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
+require('jest-fetch-mock').enableMocks();

plugins/inventory-backend/tsconfig.json

@@ -10,6 +10,7 @@
     "target": "es5",
     "module": "commonjs",
     "esModuleInterop": true,
+    "lib": ["es2019"],
     "types": ["node", "jest"]
   }
 }