​

Running a Node.js application in the background

​

Method 1: Using nohup

nohup node index.js &

• nohup: Command to run the process immune to hangups.
• node index.js: Your Node.js application entry point.
• &: Runs the process in the background.

​

Method 2: Using screen

1. Start a new screen session:
   screen -S my-node-app
   
2. Run your Node.js application:
   node index.js
   
3. Detach from the screen session by pressing Ctrl + A, then D.
4. To reattach to the session later:
   screen -r my-node-app
   

​

Method 3: Using tmux

1. Start a new tmux session:
   tmux new -s my-node-app
   
2. Run your Node.js application:
   node index.js
   
3. Detach from the tmux session by pressing Ctrl + B, then D.
4. To reattach to the session later:
   tmux attach -t my-node-app
   

​

Method 4: Using pm2

1. Install pm2 globally:
   npm install -g pm2
   
2. Start your Node.js application with pm2:
   pm2 start index.js
   
3. To list all running applications:
   pm2 list
   
4. To save the process list and resurrect them on reboot:
   pm2 save
   pm2 startup
   

​

Method 5: Using Systemd

1. Create a new service file for your application:
   sudo nano /etc/systemd/system/my-node-app.service
   
2. Add the following content to the service file:
   [Unit]
   Description=My Node.js Application
   After=network.target
   
   [Service]
   ExecStart=/usr/bin/node /path/to/your/index.js
   Restart=always
   User=your-username
   Group=your-groupname
   Environment=PATH=/usr/bin:/usr/local/bin
   Environment=NODE_ENV=production
   WorkingDirectory=/path/to/your/application
   
   [Install]
   WantedBy=multi-user.target
   
3. Reload systemd to apply the new service:
   sudo systemctl daemon-reload
   
4. Start your service:
   sudo systemctl start my-node-app
   
5. Enable the service to start on boot:
   sudo systemctl enable my-node-app
   

​

Summary

• nohup is simple and easy.
• screen and tmux are great for interactive processes.
• pm2 offers advanced features for managing and monitoring Node.js applications.
• systemd integrates well with the system’s init process and is robust for production environments.