I created a script in nodejs that extract data from database and create a file with all db data. I create also a webserver node js listening on port 3000 and with forever is working in listening mode all time. But now the script is without web interface and use a command line prompt and other modules. How remote users can use a remote script like : node scrip.js like a command shell prompt on locale machine ?
This code working but in-globe only hello world not my prompt command and db retrieve info. Thanks
var app = connect().use(connect.static('public')).listen(3000, "0.0.0.0");
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(3000, '127.0.0.1');
console.log('Server running at http://127.0.0.1:3000/');
I'm not completely sure I understand what you are asking. But if you are just asking how to communicate with a local server running on port 3000.
Then if this is a GET request, you could simply type 'http://localhost:3000/' in a browser, or you could use a tool like postman, I recommend the Chrome app.
Local server is listening on port 3000, but i can see only hello world. But when one user access to my url http://ip:3000/ needs to use a command shell like >
node script.js because i have different operations db retrieve information and input user data from command line input.
I would like to run a website developed with node.js in local.
I already installed node.js but when I lauch a .js file on my terminal, nothing happen ( $ node file.js )
Also, I guess I have to simulate a server ? How can I do that with node?
You can start a simple server with the example that can be found on nodejs.org:
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(1337, "127.0.0.1");
console.log('Server running at http://127.0.0.1:1337/');
https://nodejs.org/en/about/
To develop a website it is very helpful to use a web framework such as Express.
http://expressjs.com/
You should use:
npm start file.js
but also be sure to check out nodemon, which is very helpful for debugging - it restarts your app on code change.
Also be sure to check out the express generator, which will set up a node+express app that you can check out to figure how to get the server and routes going.
I set up a Node JS server, and made a request to it, it just loads and loads and eventually says "Server not found". Here is the code for my file:
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');
When going to externalIP:1337, the phenomenon described above happens. I am running Ubuntu 14.04, node JS version 0.10.32.
What is going on?
You're specifically listening to 127.0.0.1 which is localhost. If you want to allow connection via the external IP, you should omit the '127.0.0.1' argument in your listen. i.e. change listen(1337, '127.0.0.1') to listen(1337). Otherwise go to localhost:1337 instead.
The problem is that you're only listening for requests on localhost. If you try to access the server from outside the system you won't get there because the server isn't listening on a LAN IP.
Change
.listen(1337, '127.0.0.1');
to
.listen(1337);
That will listen on all available network interfaces on the system. You could specify a LAN IP (just like you did for localhost) if you wanted to listen on a specific network interface.
Sorry.
Apparently tomcat was also using port 80. So by disabling tomcat I got it to work.
Thanks.
I have a Node.js/Express.js app running on my server that only works on port 3000 and I'm trying to figure out why. Here's what I've found:
Without specifying a port (app.listen()), the app runs but the web page does not load.
On port 3001 (app.listen(3001)) or any other port that is not in use, the app runs but the web page does not load.
On port 2999, the app throws an error because something else is using that port.
On port 3000, the app runs and the web page loads fine.
I know that Express apps default to port 3000. But strangely, my app only runs when I explicitly make it run on port 3000 (app.listen(3000)).
I found this on line 220 of /usr/bin/express:
app.set(\'port\', process.env.PORT || 3000);
Which is doing as previously stated: setting the port to what is specified or to 3000 if nothing is specified.
How could I make my app work on a different port such as 8080 or 3001?
Thanks!
Edit: Code Sample (Very Simple Node/Express App)
var express = require("express");
var app = express();
app.get('/', function(req, res){
res.send('hello world');
});
// Only works on 3000 regardless of what I set environment port to or how I set [value] in app.set('port', [value]).
app.listen(3000);
The following works if you have something like this in your app.js:
http.createServer(app).listen(app.get('port'),
function(){
console.log("Express server listening on port " + app.get('port'));
});
Either explicitly hardcode your code to use the port you want, like:
app.set('port', process.env.PORT || 3000);
This code means set your port to the environment variable PORT or if that is undefined then set it to the literal 3000.
Or, use your environment to set the port. Setting it via the environment is used to help delineate between PRODUCTION and DEVELOPMENT and also a lot of Platforms as a Service use the environment to set the port according to their specs as well as internal Express configs. The following sets an environment key=value pair and then launches your app.
$ PORT=8080 node app.js
In reference to your code example, you want something like this:
var express = require("express");
var app = express();
// sets port 8080 to default or unless otherwise specified in the environment
app.set('port', process.env.PORT || 8080);
app.get('/', function(req, res){
res.send('hello world');
});
// Only works on 3000 regardless of what I set environment port to or how I set
// [value] in app.set('port', [value]).
// app.listen(3000);
app.listen(app.get('port'));
In bin/www, there is a line:
var port = normalizePort(process.env.PORT || '3000');
Try to modify it.
Try this
$ PORT=8080 node app.js
Try to locate the bin>www location and try to change the port number...
The default way to change the listening port on The Express framework is to modify the file named www in the bin folder.
There, you will find a line such as the following
var port = normalizePort(process.env.PORT || '3000');
Change the value 3000 to any port you wish.
This is valid for Express version 4.13.1
Just a note for Mac OS X and Linux users:
If you want to run your Node / Express app on a port number lower than 1024, you have to run as the superuser:
sudo PORT=80 node app.js
In the lastest version of code with express-generator (4.13.1) app.js is an exported module and the server is started in /bin/www using app.set('port', process.env.PORT || 3001) in app.js will be overridden by a similar statement in bin/www.
I just changed the statement in bin/www.
Noticed this was never resolved... You likely have a firewall in front of your machine blocking those ports, or iptables is set up to prevent the use of those ports.
Try running nmap -F localhost when you run your app (install nmap if you don't have it). If it appears that you're running the app on the correct port and you can't access it via a remote browser then there is some middleware or a physical firewall that's blocking the port.
Hope this helps!
The line you found just looks for the environmental variable PORT, if it's defined it uses it, otherwise uses the default port 3000. You have to define this environmental variable first (no need to be root)
export PORT=8080
node <your-app.js>
If you want to show something you're connected on 3000
var express = require('express')
var app = express()
app.get('/', function (req, res) {
res.send('Hello World!')
})
app.listen(3000, function () {
console.log('Example app listening on port 3000!')
})
I hope that will be helpful to you
Answer according to current version of express
If you talk about the current version of express, if you run app.listen() to start listening without specifying port, Express will chose a random port for your application, to find out about which port it is currently running on use
app.listen(0, () => {
console.log(app.address().port)
}
should output the port of your app. Moreover that first parameter 0 can be totally ignored but is not recommended
In app.js, just add...
process.env.PORT=2999;
This will isolate the PORT variable to the express application.
I am using the minimist package and the node startup arguments to control the port.
node server.js --port 4000
or
node server.js -p 4000
Inside server.js, the port can be determined by
var argv = parseArgs(process.argv.slice(2))
const port = argv.port || argv.p || 3000;
console.log(`Listening on port ${port}...`)
//....listen(port);
and it defaults to 3000 if no port is passed as an argument.
You can then use listen on the port variable.
Make sure you are running from that folder of your application, where you have the package.json.
I think the best way is to use dotenv package and set the port on the .env config file without to modify the file www inside the folder bin.
Just install the package with the command:
npm install dotenv
require it on your application:
require('dotenv').config()
Create a .env file in the root directory of your project, and add the port in it (for example) to listen on port 5000
PORT=5000
and that's it.
More info here
If you are using Nodemon my guess is the PORT 3000 is set in the nodemonConfig.
Check if that is the case.
I'm building an application that links to a node.js hosted on my home computer (78.233.79.103:8000)
The server is properly istalled (if you go to the addres I gave you'll se the socket.io works)
If I run the server in localhost with
node server.js
all is good, the application works
Then when I run the application on my other pc or on my iPad (I wrapped it with phoneGap so it's just a web app included in a native iOS app), trying to connect the io on 78.233.79.103:8000 i got the console log:
io is not defined
here is my sourcecode: https://github.com/synbioz/puissance4
look for the server.js
I know I only call io = require('socket.io').listen(PORT); but kwnow also I should create something like:
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(8000, '78.233.79.103');
that actually doesn't works
Any idea?
probably because .listen() doesn't return this.
try writing them in separate lines.
var io = require('socket.io');
io.listen(PORT);