Updated server.js to handle MongoDb Exception.

backend/server.js

@@ -6,15 +6,37 @@ import Info from './models/Info';
 
 const app = express();
 const router = express.Router();
-var port = 4000;
+var port = 3000;
 app.use(cors());
 // var bodyParser = require('body-parser');
 app.use(bodyParser.json());
 app.use(bodyParser.urlencoded({ extended: true }));
-mongoose.connect('mongodb://localhost:27017/form',{ useNewUrlParser: true } );
+var dbURL = 'mongodb://127.0.0.1:27017/form';
+mongoose.connect(dbURL, { useNewUrlParser: true } );
 
 const connection = mongoose.connection;
 
+connection.on('error', function (err) {
+  // If first connect fails because mongod is down, try again later.
+  // This is only needed for first connect, not for runtime reconnects.
+  // See: https://github.com/Automattic/mongoose/issues/5169
+  if (err.message && err.message.match(/failed to connect to server .* on first connect/)) {
+    console.log(new Date(), String(err));
+
+    // Wait for a bit, then try to connect again
+    setTimeout(function () {
+      console.log("Retrying first connect...");
+      connection.openUri(dbURL).catch(() => {});
+      // Why the empty catch?
+      // Well, errors thrown by db.open() will also be passed to .on('error'),
+      // so we can handle them there, no need to log anything in the catch here.
+      // But we still need this empty catch to avoid unhandled rejections.
+    }, 20 * 1000);
+  } else {
+    // Some other error occurred.  Log it.
+    console.error(new Date(), String(err));
+  }
+});
 connection.once('open', () => {
   console.log('MongoDB database connection established successfully!');
 });

src/app/home/info.service.ts

@@ -6,7 +6,10 @@ import { HttpClient } from '@angular/common/http';
 })
 export class InfoService {
 
-  uri = 'http://localhost:4000';
+  // uri = 'http://54.226.207.32:4000';
+  // uri = 'http://localhost:4000';
+  //when pushing to github uncomment this
+  uri = 'http://54.197.12.23:3000';
 
   constructor(private http: HttpClient) { }