node.js: route request to different port on same host - node.js

I have a host computer which serves a number of webapplications (not node.js based). It does this using different ports. This means that for example the following applications are live:
app1: http://hostname:3000
app2: http://hostname:3001
app3: http://hostname:3003
Next to that I have a node.js based webapp (running on port 80) which I want to use as a sort of router. When someone navigates to http://localhost/app/app1. I want it to navigate to http://hostname:3000. This is relatively straightforward using a simple redirect. However, I would want to preserve the url http://localhost/app/app1. Can someone point me to a way to make this work using node.js/express?
My routing logic looks somewhat like this (pseudo-code).
app.route('/app/:appName')
.get(appEngine.gotoApp);
appEngine.gotoApp = function(req, res) {
redirectToApp logic
}

You probably better use Nginx setting up a reverse proxy with different locations per application.
It's not what you ask for because it does not use node.js, but if it's the only purpose, Nginx really suits your needs.
For example a Nginx configuration file like should work the way you want :
server {
listen 80;
server_name myapp.com;
location /app1 {
proxy_pass http://APP_PRIVATE_IP_ADDRESS:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location /app2 {
proxy_pass http://APP_PRIVATE_IP_ADDRESS:3001;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location /app3 {
proxy_pass http://APP_PRIVATE_IP_ADDRESS:3003;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}

If you use express, you can try to create the app with the cli express application generator.
It creates an express app and returns it with module exports.
In the server.js file it pass to listen function of the server instance the express app object.
You can create more server object and listen different app with different port.
var server = http.createServer(app);
server.listen(port);
var server2 = http.createServer(app2);
server2.listen(port2);
If you want to point different app based on the url, you can instance an express router instead of express object.
var app1 = express.Router();
Then you can set all your routes into this object with classic get or post or other methods.
Now you are able to pass the router as a middleware of your main express app.
app.use( "app1/", app1 );
You can also pass an express app to middleware, instead of router object, in order to gain the possibility of exec the app with a different url and port server listening.

There is a nice http-proxy lib designed exactly for that!
const httpProxy = require('http-proxy');
const url = require('url');
const proxy = httpProxy.createProxy();
const options = {
'/app/app1': 'http://localhost:3000',
'/app/app2': 'http://localhost:3001',
'/app/app3': 'http://localhost:3003',
}
require('http').createServer((req, res) => {
const pathname = url.parse(req.url).pathname;
for (const [pattern, target] of Object.entries(options)) {
if (pathname === pattern ||
pathname.startsWith(pattern + '/')
) {
proxy.web(req, res, {target});
}
}
}).listen(80);

Related

What's the correct way to get rid of /public from a domain using node.js and nginx?

I've been structuring my website as follows:
someSite
app.js
public
index.html
css
assets
Project1
Project2
...
I'd like for the path to /public/Project1/index.html to be accessible by going to someSite.com/Project1, and similarly for subfolders. I've found this can be accomplished like this:
var express = require('express');
var app = express();
var http = require('http').createServer(app);
var io = require('socket.io')(http);
app.use('/public',express.static(path.join(__dirname, 'public')));
app.get('/', (req, res) => {
res.sendFile(__dirname + '/public/index.html');
});
app.get('/Project1', (req, res) => {
res.sendFile(__dirname + '/public/Project1/index.html');
});
But I don't know if this is standard, or inefficient. It's also breaking all of my relative calls, such as <img src="../assets/someImage.svg">, which no longer point to the correct place. It can be fixed by using absolute urls everywhere, but that feels wrong.
I'm using nginx as a reverse proxy server, which I think is the right place to make this change. My configuration is as follows:
server {
listen 80;
server_name someSite.com www.someSite.com;
rewrite ^(.*) https://$host$1 permanent;
}
server {
listen 443 ssl;
root /var/www/someSite/public;
server_name someSite.com;
ssl_certificate /path/to/credentials.crt;
ssl_certificate_key /path/to/credentials.key;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers HIGH:!aNULL:!MD5;
location / {
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_http_version 1.1;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $host;
proxy_pass http://localhost:3000/;
}
}
I still haven't figured out exactly what's wrong with my nginx configuration, but the hosting from node issue was just a matter of changing
app.use('/public',express.static(path.join(__dirname, 'public')));
to
app.use('/',express.static(path.join(__dirname, 'public')));
and removing subsequent app.get calls.

Node: PORT 443 requires elevated privileges error

I'm using PM2 to start the application and I pass PORT=443 as a parameter while starting the app. However, it returns with an error saying "PORT 443 requires elevated privileges". Though I have generated the certificate and key using openssl and referenced in the code. Appreciate your support
#!/usr/bin/env node
var app = require('../app');
var debug = require('debug')('ls-templates-server:server');
var https = require('https');
var fs = require('fs');
/**
* Get port from environment and store in Express.
*/
var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);
var options = {
key: fs.readFileSync('/home/admin/cert/server.key'),
cert: fs.readFileSync('/home/admin/cert/server.cert')
};
var httpsServer = https.createServer(options, app);
/* for https (production stage) */
httpsServer.listen(port, "0.0.0.0");
httpsServer.on('error', onError);
httpsServer.on('listening', onListening);
/**
* Normalize a port into a number, string, or false.
*/
function normalizePort(val) {
var port = parseInt(val, 10);
if (isNaN(port)) {
// named pipe
return val;
}
if (port >= 0) {
// port number
return port;
}
return false;
}
/**
* Event listener for HTTP server "listening" event.
*/
function onListening() {
var addr = httpsServer.address();
var bind = typeof addr === 'string'
? 'pipe ' + addr
: 'port ' + addr.port;
debug('Listening on ' + bind);
}
Option 1 .
Run PM2 as sudo
If it doesn't work, achieve it using authbind
sudo apt-get install authbind
sudo touch /etc/authbind/byport/443
sudo chown %user% /etc/authbind/byport/443
sudo chmod 755 /etc/authbind/byport/443
Edit ~/.bashrc file and add
+alias pm2='authbind --deep pm2'
at the end of the file, and run
source ~/.bashrc
Finally ensure that pm2 is updated with authbind:
authbind --deep pm2 update
Option 2
Use a different PORT and use Nginx to reverse proxy your application
Eg : change your PORT to 3000
In Nginx , create a server block which forwards the request to your application.
Server Block Eg :
server {
#listen [::]:80;
server_name your-domain.com
#root /var/www/example.com;
#index index.html;
client_max_body_size 20M;
location / {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_pass http://localhost:3000;
proxy_redirect off;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";
proxy_connect_timeout 500000;
proxy_send_timeout 500000;
proxy_read_timeout 500000;
send_timeout 500000;
}
listen 443 ssl;
ssl_certificate /home/admin/cert/server.cert;
ssl_certificate_key /home/admin/cert/server.key;
if ($scheme = http) {
return 301 https://$server_name$request_uri;
}
}
It's best to use Nginx / Authbind method, It's good to run as little as possible as a privileged user, as you want to restrict the potential damage in case someone exploits your program. You don't want to run your Node code as root unless you absolutely have to.
refer
https://pm2.keymetrics.io/docs/usage/specifics/#listening-on-port-80-w-o-root
https://www.digitalocean.com/community/tutorials/how-to-use-pm2-to-setup-a-node-js-production-environment-on-an-ubuntu-vps

how to make Nodejs redirect work when called via Vuejs

I have created and tested the POST and GET request methods in Nodejs such that I can send the user through the Gocardless sign-up API perfectly fine.
This is a sign-up form provided by their API which allows them to input their details and then returns the user back after they fill it in.
But when I set up a front-end using Vuejs and make the same calls previously made from the back end using Axios, it seems that because the "redirect_url" fed back to me from the GC API had previously been fed directly into the browser url before, now, because it seems vue-router has control of the browser, I'm getting a cross origin error.
How can I configure the files to have the Nodejs back end acting as if it had control of the browser?
The end points are described here:
https://developer.gocardless.com/api-reference/#core-endpoints-redirect-flows
My nginx default is:
server {
charset UTF-8;
listen 80;
root /srv/www/sitename/;
index index.html;
server_name sitename.com;
location /api/ {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_http_version 1.1;
proxy_set_header X-NginX-Proxy true;
proxy_pass http://sitename.com:8081;
proxy_ssl_session_reuse off;
proxy_set_header Host $http_host;
proxy_redirect off;
}
location / {
try_files $uri.html $uri $uri/ /index.html;
}
My button from Vuejs front end:
completeOrder()
..and uses axios this way:
import axios from 'axios'
export default() => {
return axios.create({
baseURL: 'http://sitename.com:8081/api'
})
}
And set it up here:
import Api from '#/services/Api'
export default {
completeOrder () {
return Api().post('order')
}
}
In the back end it sends:
app.post('/api/order', function (req, res){
rp({
//rp is npm request-promise
uri: BASE_URL + "/redirect_flows",
method: 'POST',
body:JSON.stringify(input_json),
headers: headers
}) // this works and API sends me the response
.then(function(response) {
var str_response =JSON.parse(response);
url = str_response['redirect_flows']['redirect_url']
// url works fine when I paste into a separate browser
res.redirect(url)
})
.catch(function (err) {
console.error(err);
})
})
Everything works up until the point:
res.redirect(url)
..where the Gocardless API response supplies me with the URL which I need to load into a browser.
It looks something like this:
https://pay-sandbox.gocardless.com/flow/RE000156
I think I need to break out of Vuejs's control of the browser via vue-router just long enough to allow the user to call the form with the redirect_url, then come back to the home page of the app again.
Any ideas very welcome!
I think you actually have a JS error. In the then block you instantiate a response, but you use a res variable to redirect.
Try chaging the variable
.then(function(response) {
var str_response = JSON.parse(response);
url = str_response['redirect_flows']['redirect_url']
// url works fine when I paste into a separate browser
response.redirect(url)
})
I am not a Vue.JS expert, so I don't know if that works, try using a vanilla JS redirect to test this feature:
window.location.href = url;
This way, you will be sure that the url works. After that, try checking out a full Vue.JS option.

How to appropriately reverse-proxy nodejs subroutes?

I am new to nodejs and nginx as well. So what I am trying to do is reverse-proxy node in nginx. I am able to do so but my subsequent routes from nodejs doesn't get reverse-proxied.
app.get('/', (req, res) => {
res.render('index');
});
app.post('/upload', (req, res) => {
upload(req, res, (err) => {
console.log(req.file);
res.render('index' , {
msg: 'File Uploaded!',
file : `uploads/${req.file.filename}`
});
});
});
So here is the basic code. '/' has the index page with a button. And when you click on the button it goes to the '/upload'.
It works without reverse proxy.
My reverse proxy is configured as below.
location /nodeAdmin/ {
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_redirect off;
proxy_buffering off;
proxy_pass http://127.0.0.1:8080/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_cache_bypass $http_upgrade;
}
So now when I go to mydomain.com/nodeAdmin I see the 'index'. But when I click on the upload button, I need to go to /upload of nodejs app but it goes to mydomain.com/upload which does not exist.
It would be great if someone could direct me in the right direction.
I think the issue lies in the html.
Your current html may have something like
upload
Making all the links "relative" should solve your problem
upload
Links starting with / will be relative to the domain, while links starting with ./ will be relative to the current directory (nodeAdmin).

Multiple node.js projects with one domain name, each using path '/' as base url. Nginx & Express.js

I am successfully able to reverse proxy multiple node.js projects to different ports as in the Nginx set up below. What I am trying to accomplish however, is viewing the url as the root when it gets to the Node.js server.
For example, When someone goes to mydomain.com/projects/music_player, is it possible to have the Express application view the request url as just '/' instead of '/projects/music_player'.
My current Nginx setup, and Express configuration example are as follows.
Nginx:
server {
listen 80;
server_name mydomain_name.com;
location / {
proxy_pass http://localhost:8080;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location /projects/music_player/ {
proxy_pass http://localhost:8000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
I want to do this:
app.get("/", function (req, res) {
res.sendFile("index.html");
});
app.listen(8000);
Instead of this:
app.get("/projects/music_player", function (req, res) {
res.sendFile("index.html");
});
app.listen(8000);
I am not sure if that is even possible. The reason is that I would like each of my node node.js/express applications to be deployable as standalone applications, without restructuring the code. I am trying to avoid having a bunch of domain names for each project, plus I think it would be pretty cool.
Yes! Of course you can.
I think the best way to do this is to rewrite your entire program into one express app, but you say you want to avoid this.
Then I think the short way with your current setup is to make each program listen to a different port and then map routes to them in your nginx.
For example:
dog.js
app.get("/", function (req, res) {
res.sendFile("dog.html");
});
app.listen(8001);
cat.js
app.get("/", function (req, res) {
res.sendFile("cat.html");
});
app.listen(8002);
And finally in your nginx config file:
server {
listen 80;
server_name mydomain_name.com;
location / {
proxy_pass http://localhost:8001;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location /cat/ {
rewrite /cat/ / break;
proxy_pass http://localhost:8002;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}
Notice the rewrite directive, this prevents for the /cat/ location from being sent to your cat.js app that only expects the / route.
I ran into this same problem, where I didn't want to fully restructure my backend services while wanting to change the endpoint to match others.
I ended up using node-http-proxy with http-proxy-rules. Grabbing an example from the http-proxy-rules github README, you're solution would resemble the following.
var http = require('http'),
httpProxy = require('http-proxy'),
HttpProxyRules = require('http-proxy-rules');
// Set up proxy rules instance
var proxyRules = new HttpProxyRules({
rules: {
'.*/test': 'http://localhost:8080/cool', // Rule (1)
'.*/test2/': 'http://localhost:8080/cool2/' // Rule (2)
},
default: 'http://localhost:8080' // default target
});
// Create reverse proxy instance
var proxy = httpProxy.createProxy();
// Create http server that leverages reverse proxy instance
// and proxy rules to proxy requests to different targets
http.createServer(function(req, res) {
// a match method is exposed on the proxy rules instance
// to test a request to see if it matches against one of the specified rules
var target = proxyRules.match(req);
if (target) {
return proxy.web(req, res, {
target: target
});
}
res.writeHead(500, { 'Content-Type': 'text/plain' });
res.end('The request url and path did not match any of the listed rules!');
}).listen(6010, cb);
Happy hacking!

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