地址：https://www.codewithharry.com/blogpost/deploy-nodejs-app-on-ubuntu/

How to deploy a Node.js application in production

In this post, we will see how to run and deploy NodeJS apps in production. Follow the steps below:

Step 1 - Install Nodejs

Let's download nodejs from Nodesource. NodeSource is a company which provides enterprise-grade Node support and maintains a repository containing the latest versions of Node.js.

curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash -

Let's install nodejs now:

sudo apt-get install -y nodejs

Check the installation of node and npm using the following commands:

node --version && npm --version

You will see the versions of nodejs and npm

Step 2 - Creating a sample nodejs file

Let's create a sample app and paste some basic code into it.

sudo vi app.js

Paste the following code inside it:

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 at http://localhost:${port}`)
})

Lets now install express so that we can run this app server:

npm install express

run the application

node app.js

You should now be able to see the hello world page when you visit http://server-ip:3000

Step 3 - Using pm2 as a process manager

Let's install and use pm2 as a process manager. Install pm2 using the commands below:

sudo npm i pm2 -g

Start the application using the following command:

pm2 start app.js

Step 4 - Configuring Nginx as a reverse proxy

Now let's configure Nginx as a reverse proxy. This will help us get the security features from Nginx. Also, we can serve static content using Nginx.

Let's install Nginx using the following command:

sudo apt install nginx

Let's create a conf file for our Nodejs app using the command below

sudo vi /etc/nginx/sites-available/nodeApp

Copy the following content to this file

server{
  server_name 165.232.177.116;

      location / {
        proxy_pass http://localhost: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;
    }
}

Activate this configuration using the command below:

sudo ln -s /etc/nginx/sites-available/nodeApp /etc/nginx/sites-enabled

Visit http://your-ip/ and your application should work fine. Happy coding!