I created a frontend app and now trying to incorporate backend into it.
ON the same frontend app i added an index.js file in the root directory, and installed express and required it in index.js file.
Very basic setup as below:
const express = require('express')
const cors = require('cors')
const port = process.env.PORT || 3001
const app = express()
app.get('/', (req, res) => {
res.send({
greetings: 'hi'
})
})
app.listen(port, () => {console.log(`Server on port ${port}`)})
Server is successfully on port 3001 as per my terminal, however, on localhost:3001 I'm not seeing any json response I set up in app.get.
It says Cannot GET / instead. When i inspected in devtool(Network) it says 404.
This seems a very straightforward setup, but what could've gone wrong here?
i just figured why. I installed nodemon but my “start” script is “node index.js”. Should’ve used “nodemon index.js”
Working now with nodemon index.ks
Your code is fine, There are no errors, I tested it and it works as expected.
However few things to note, Keep Backend in Seperate folder/dirctory unless required.
Coming back to your question, There are many possiblity such as some modules are not installed properly
try running following command
//this will install if any library is currupt or not installed properly
npm i
if it doesn't work then try clearing cache
Also keep in mind, In nodeJS dev server does not automatically refresh changes, you need to restart server to see changes or you can use dev dependancy called Nodemon (this will auto restart server on saving changes)
Related
I've read other forums on installing express, I have run
npm install express -g on command prompt as admin.
I did this command a few times and restarted my computer multiple times but Express is still not recognized.
Any help is appreciated.
Express isn't a web server; it is a framework for building web servers.
The express package doesn't provide anything directly executable.
The express documentation has a getting started guide.
If you aren't trying to do server-side programming using Node.js and just want an HTTP server, then the http-server package may be more your speed.
Assuming you’ve already installed Node.js, create a directory to hold your application and make that your working directory.
then follow the below command
npm init
follow step press enter and after
npm install express
make index.js file paste below hello work program.
const express = require('express')
const app = express()
const port = 3000
app.get('/', (req, res) => {
res.send('Hello World!')
})
app.listen(port, () => {
console.log(`Example app listening on port ${port}`)
})
Now you can run file using below command
node index.js
Open your broswer and enter URL : http://localhost:3000/
You can display Hello World!
You have successfully installed node js and express js program.
I'm trying to deploy my MERN app on Elastic Beanstalk, and I seem to be running into a final problem that I just cannot solve.
My app works fine when running my server locally (running node server), but when running on elastic beanstalk, the page never loads.
Upon inspection, the static elements are not being loaded, as seen in Dev Tools:
Image showing ERR_CONNECTION_TIMED_OUT in dev tools
I checked all the EB logs and did not find any errors or helpful messages.
I'm thinking the problem is with EB not being able to find my static files somehow. It should however, my build files are not ignored by git and are deployed to EB.
Here's some background about my project:
My backend and client code are in one project, with the following structure:
project
server.js
frontend
build
static
index.html
I run my app by building the react site, then running "node server" which runs great
Here is the relevent code from my server.js :
const port = process.env.PORT || 8081;
app.use(express.static(path.join(__dirname, 'frontend/build')));
app.get('/*', function (req, res) {
res.sendFile(path.join(__dirname, 'frontend/build/index.html'));
});
app.listen(port, () => {
console.log(`Server is running on port: ${port}`);
});
The server is successfully sending logs that the server is running and that the database has established a connection. So it seems the server is fine, it's just that the front-end is the problem.
eb config file:
option_settings:
aws:elasticbeanstalk:container:nodejs:
NodeCommand: "npm start"
aws:elasticbeanstalk:application:environment:
PORT: 8081
NODE_ENV: production
aws:elasticbeanstalk:container:nodejs:staticfiles:
/static: /frontend/build/static
I'm at a loss on how to solve this. The EB was deployed through the CLI and I haven't messed with any settings. I'm letting EB know where my static files are, and I believe it would say not found, rather than timing out.
Any help would be appreciated
Solved.
The problem was with using Helmet in my express server. I had ommited the code, thinking it not relevant, but here is the top portion of server.js, with the last line being the relevant portion:
const AWS = require('aws-sdk');
const cors = require('cors');
const express = require('express');
const helmet = require('helmet');
const mongoose = require('mongoose');
const path = require('path');
let Download = require('./models/Download.js');
require('dotenv').config();
const app = express();
const port = process.env.PORT || 8081;
app.use(helmet());
Not using helmet solves the issue.
To be honest, I'm not sure why this is the problem.
I assume that the problem is that helmet provides some security that my bare bones EB simply is not providing.
EDIT: Specifically, the problem is with CSP. Setting contentSecurityPolicy to false in Helmet is enough to fix the issue.
I am trying to run the google assistant example webhook nodejs application(index.js) on my own server, but don't know what is the webhosting setup for this..
https://codelabs.developers.google.com/codelabs/your-first-action-on-google-with-webhook/#2
What is the environment to run this app on my server? Since it's not running as a listening server, I can't use nginx, node_cgi is not mature with apache, how am I supposed to run this sample?
Excellent point, and you should be sure to file a bug request on the page to indicate it is unclear.
The code, as presented, is meant to run using Google Cloud Functions.
This doesn't mean you can't run it on your own server - just that you need to know how to run a Node.js server outside of your Apache or Nginx environment. I've seen a number of configurations, but typically you'll have the Node.js server application running and listening to a local port and have a proxy between your externally facing web server at a particular path and this port.
But even that isn't sufficient in this case - the code itself doesn't listen on a port - it expects to be handed a request and response object in the form that Express.js with a JSON middleware can handle. To do that, you'll need to have installed the Express.js library and then start listening with code such as:
const express = require('express');
const app = express();
app.use( express.json() );
app.get('/', (req, res) => exports.bitcoinInfo( req, res ));
app.listen(3000, () => console.log('App listening on port 3000!'));
Thanks for the help to #Prisoner and #Ido Green link works even better! The minimum to run the sample I did the following:
Create a new nodejs project with mainfile main.js, install express and actions-on-google
mkdir googleActionServer
cd googleActionServer
npm init
npm install --save actions-on-google
npm install --save express`
Copy the index.js from google and put this into main.js
const express = require('express');
const bitcoinInfo = require("./index");
const app = express();
app.use( express.json() );
app.post('/', (req, res) => bitcoinInfo.bitcoinInfo( req, res ));
app.listen(3000, () => console.log('App listening on port 3000!'));
Start the application by running:
node ./main.js
To test with DialogFlow, download and install ngrok to /usr/local/bin for ex and then run:
ngrok http 3000
Ngrok will give you an url that is accesible from outside and forward the requests to the nodejs app. It will also create a https for you, so copy paste the https address into DialogFlow webhook address and you are set to go
I have been developing an app from the create-react-app starting project.
Today I have been doing the following on my local machine:
deploying my react app using react-scripts start
deploying my react app by using react-scripts build then either serving the build by either...
(A) using the [npm module serve][] as follows serve -p 4001
(B) or attempting to server using a express app like follows:
Express app:
const express = require('express');
const path = require('path');
const app = express();
app.use(express.static(path.join(__dirname, 'build')));
app.get('/', function (req, res) {
res.sendFile(path.join(__dirname, 'build', 'index.html'));
});
app.listen(4001);
I've just restarted my computer and it's still serving the site at:
http://localhost:4001/ and I cannot figure out how to stop it.
I wouldn't mind the continuous deployment of this server but when I build the project again. The changes are not reflected.
The only work around I've come up with is to now deploy at port 4025 and use the Express method coded above.
How the hell can I get rid of this weird residual app that continues to run (via some react process) at port 4001?
I'd really like that port back for sake of keeping it the same across different machines :(
Turns out that chrome keeps react apps running even if the server stops providing them.
Go to chrome://serviceworker-internals and unregister them.
First i installed the node js with webmatrix and ran a sample node js app. the app was assigned a random port. http://localhost:62369/. After that i installed the express module. As said in their doc. i wrote,
var app = express();
app.get('/',function (req, res) {
res.send('hello world!!');
})
app.listen(3000);
Then i restarted the server. The launched browser was still pointing to http://localhost:62369/ instead of port 3000. Moreover http://localhost:3000/ was not working.
I suggest you to run this code so you can see if you have any problem on saving the code with your IDE:
var app = express(),
port = 4555;
app.get('/',function (req, res) {
res.send('hello world!!');
})
console.log("Server is running on " + port);
app.listen(port);
After that, you need to change the port variable only. It's helpful if you comment what you see after running this code on the console.
make sure that you've saved your code in your file (open it with another editor, maybe something's wrong with your editor), close the command line window and open it again. try to run server. I'm sure the problem is not because of node or express. Try to check everything again.
And also run your server with command line:
cd path/folder
node myFile
I don't know what are you using to run server, but if it's something with UI (in comments you mentioned a click) it can cache your code or something like that. So it's safer to run with commend line.