backend-app-api: refactor hostFactory into createHttpServer

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/backend-app-api/package.json

@@ -48,12 +48,14 @@
     "minimatch": "^5.0.0",
     "node-forge": "^1.3.1",
     "selfsigned": "^2.0.0",
+    "stoppable": "^1.1.0",
     "winston": "^3.2.1"
   },
   "devDependencies": {
     "@backstage/cli": "workspace:^",
     "@types/fs-extra": "^9.0.3",
-    "@types/node-forge": "^1.3.0"
+    "@types/node-forge": "^1.3.0",
+    "@types/stoppable": "^1.1.0"
   },
   "files": [
     "dist",

packages/backend-app-api/src/lib/http/createHttpServer.ts

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2020 The Backstage Authors
+ *
+ * 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 * as http from 'http';
+import * as https from 'https';
+import stoppableServer from 'stoppable';
+import { RequestListener } from 'http';
+import { LoggerService } from '@backstage/backend-plugin-api';
+import { HttpServerOptions, ExtendedHttpServer } from './types';
+import { getGeneratedCertificate } from './getGeneratedCertificate';
+
+/**
+ * Creates a Node.js HTTP or HTTPS server instance.
+ *
+ * @public
+ */
+export async function createHttpServer(
+  listener: RequestListener,
+  options: HttpServerOptions,
+  deps: { logger: LoggerService },
+): Promise<ExtendedHttpServer> {
+  const server = await createServer(listener, options, deps);
+
+  const stopper = stoppableServer(server, 0);
+
+  return Object.assign(server, {
+    start() {
+      return new Promise<void>((resolve, reject) => {
+        const handleStartupError = (error: Error) => {
+          server.close();
+          reject(error);
+        };
+
+        server.on('error', handleStartupError);
+
+        const { host, port } = options.listen;
+        server.listen(port, host, () => {
+          server.off('error', handleStartupError);
+          deps.logger.info(`Listening on ${host}:${port}`);
+          resolve();
+        });
+      });
+    },
+
+    stop() {
+      return new Promise<void>((resolve, reject) => {
+        stopper.stop((error?: Error) => {
+          if (error) {
+            reject(error);
+          } else {
+            resolve();
+          }
+        });
+      });
+    },
+
+    port() {
+      const address = server.address();
+      if (typeof address === 'string' || address === null) {
+        throw new Error(`Unexpected server address '${address}'`);
+      }
+      return address.port;
+    },
+  });
+}
+
+async function createServer(
+  listener: RequestListener,
+  options: HttpServerOptions,
+  deps: { logger: LoggerService },
+): Promise<http.Server> {
+  if (options.https) {
+    const { certificate } = options.https;
+    if (certificate.type === 'generated') {
+      const credentials = await getGeneratedCertificate(
+        certificate.hostname,
+        deps.logger,
+      );
+      return https.createServer(credentials, listener);
+    }
+    return https.createServer(certificate, listener);
+  }
+
+  return http.createServer(listener);
+}

packages/backend-app-api/src/lib/http/getGeneratedCertificate.ts

@@ -16,86 +16,16 @@
 
 import fs from 'fs-extra';
 import { resolve as resolvePath, dirname } from 'path';
-import express from 'express';
-import * as http from 'http';
-import * as https from 'https';
 import { LoggerService } from '@backstage/backend-plugin-api';
-import { HttpsSettings } from './config';
 import forge from 'node-forge';
 
 const FIVE_DAYS_IN_MS = 5 * 24 * 60 * 60 * 1000;
 
 const IP_HOSTNAME_REGEX = /:|^\d+\.\d+\.\d+\.\d+$/;
 
-/**
- * Creates a Http server instance based on an Express application.
- *
- * @param app - The Express application object
- * @param logger - Optional Winston logger object
- * @returns A Http server instance
- *
- */
-export function createHttpServer(
-  app: express.Express,
-  logger?: LoggerService,
-): http.Server {
-  logger?.info('Initializing http server');
-
-  return http.createServer(app);
-}
-
-/**
- * Creates a Https server instance based on an Express application.
- *
- * @param app - The Express application object
- * @param httpsSettings - HttpsSettings for self-signed certificate generation
- * @param logger - Optional Winston logger object
- * @returns A Https server instance
- *
- */
-export async function createHttpsServer(
-  app: express.Express,
-  httpsSettings: HttpsSettings,
-  logger?: LoggerService,
-): Promise<http.Server> {
-  logger?.info('Initializing https server');
-
-  let credentials: { key: string | Buffer; cert: string | Buffer };
-
-  if ('hostname' in httpsSettings?.certificate) {
-    credentials = await getGeneratedCertificate(
-      httpsSettings.certificate.hostname,
-      logger,
-    );
-  } else {
-    logger?.info('Loading certificate from config');
-
-    credentials = {
-      key: httpsSettings?.certificate?.key,
-      cert: httpsSettings?.certificate?.cert,
-    };
-  }
-
-  if (!credentials.key || !credentials.cert) {
-    throw new Error('Invalid HTTPS credentials');
-  }
-
-  return https.createServer(credentials, app) as http.Server;
-}
-
-function getCertificateExpiration(cert: string, logger?: LoggerService) {
-  try {
-    const crt = forge.pki.certificateFromPem(cert);
-    return crt.validity.notAfter.getTime() - Date.now();
-  } catch (error) {
-    logger?.warn(`Unable to parse self-signed certificate. ${error}`);
-    return 0;
-  }
-}
-
-async function getGeneratedCertificate(
+export async function getGeneratedCertificate(
   hostname: string,
-  logger?: LoggerService,
+  logger: LoggerService,
 ) {
   const hasModules = await fs.pathExists('node_modules');
   let certPath;
@@ -109,24 +39,30 @@ async function getGeneratedCertificate(
   }
 
   if (await fs.pathExists(certPath)) {
-    const cert = await fs.readFile(certPath);
-    const remainingMs = getCertificateExpiration(cert.toString(), logger);
-    if (remainingMs > FIVE_DAYS_IN_MS) {
-      logger?.info('Using existing self-signed certificate');
-      return {
-        key: cert,
-        cert,
-      };
+    try {
+      const cert = await fs.readFile(certPath);
+
+      const crt = forge.pki.certificateFromPem(cert.toString());
+      const remainingMs = crt.validity.notAfter.getTime() - Date.now();
+      if (remainingMs > FIVE_DAYS_IN_MS) {
+        logger.info('Using existing self-signed certificate');
+        return {
+          key: cert,
+          cert,
+        };
+      }
+    } catch (error) {
+      logger.warn(`Unable to use existing self-signed certificate, ${error}`);
     }
   }
 
-  logger?.info('Generating new self-signed certificate');
-  const newCert = await createCertificate(hostname);
+  logger.info('Generating new self-signed certificate');
+  const newCert = await generateCertificate(hostname);
   await fs.writeFile(certPath, newCert.cert + newCert.key, 'utf8');
   return newCert;
 }
 
-async function createCertificate(hostname: string) {
+async function generateCertificate(hostname: string) {
   const attributes = [
     {
       name: 'commonName',

packages/backend-app-api/src/lib/http/types.ts

@@ -14,6 +14,21 @@
  * limitations under the License.
  */
 
+import * as http from 'http';
+
+/**
+ * An HTTP server extended with utility methods.
+ *
+ * @public
+ */
+export interface ExtendedHttpServer extends http.Server {
+  start(): Promise<void>;
+
+  stop(): Promise<void>;
+
+  port(): number;
+}
+
 /**
  * Options for starting up an HTTP server.
  *

yarn.lock

@@ -3388,6 +3388,7 @@ __metadata:
     "@types/express": ^4.17.6
     "@types/fs-extra": ^9.0.3
     "@types/node-forge": ^1.3.0
+    "@types/stoppable": ^1.1.0
     cors: ^2.8.5
     express: ^4.17.1
     express-promise-router: ^4.1.0
@@ -3395,6 +3396,7 @@ __metadata:
     minimatch: ^5.0.0
     node-forge: ^1.3.1
     selfsigned: ^2.0.0
+    stoppable: ^1.1.0
     winston: ^3.2.1
   languageName: unknown
   linkType: soft